Sloshing Motion in a Real-Scale Water Storage Tank under Nonlinear Ground Motion
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
water Article Sloshing Motion in a Real-Scale Water Storage Tank under Nonlinear Ground Motion Heng Jin 1,2 , Ruiyin Song 1, * and Yi Liu 1,3 1 Ningbo Institute of Technology, Zhejiang University, Ningbo 315000, China; jinheng@nit.zju.edu.cn (H.J.); liuyilulu@nit.zju.edu.cn (Y.L.) 2 Ningbo Institute of Dalian University of Technology, Ningbo 315016, China 3 Ningbo Shenglong Group Company Limited, Ningbo 315105, China * Correspondence: sry@nit.zju.edu.cn Received: 9 June 2020; Accepted: 18 July 2020; Published: 24 July 2020 Abstract: Water storage tanks in cities are usually large and are occasionally affected by earthquakes. A sudden earthquake can cause pressure pulses that damage water containers severely. In this study, the sloshing motion in a high filling level tank caused by seismic excitation is investigated by the numerical method in a 2D model. Two well-studied strong earthquakes are used to analyze the broadband frequency nonlinear displacement of the tank both in the longitudinal and vertical directions. Based on careful experimental verification, the free surface motion and the elevations at the side wall are captured, and the sloshing pressure response is examined. The results show that the 2D section of the cylindrical tank can be used to estimate the maximum response of the 3D sloshing, and the water motions under the seismic excitations are consistent with the modal characteristics of the sloshing. The time histories response of the water motion reflected that the sloshing response is hysteretic compared with the seismic excitation. The anti-seismic ability of the damping baffle shows that its effect on sloshing pressure suppression is limited, and further study on the seismic design of water tanks in earthquake-prone regions is needed. Keywords: sloshing; ground motion; water storage tank; damping baffle; response analysis 1. Introduction Water is the source of life. It is an essential element in human production and life. Almost all fields including agricultural irrigation, hydropower, climate, etc., are inextricably linked to water; therefore, the management of the water resources is necessary. The utilization, environmental health, and storage safety of the water resources all are part of the management of water. The water tanks, as the container for water storage, are usually large and have higher safety standards. Therefore, it is very important to ensure the safety of the water tank under external environmental loads such as an earthquakes or wind. In high seismic regions, the seismic design of water tanks has attracted more attention from structural engineers as the urban water storage demand increases [1,2]. The design of a liquid container is of particular concern when the sloshing frequency is close to the seismic excitation frequency (i.e., resonance), because pressure pulses from the dynamic load may seriously damage the system [3,4]. Sloshing has been widely studied as a typical fluid motion phenomenon [5]. The free surface motion and the resonance frequency location are the key factors determining the hydrodynamic load in the container, and the movement of the water body in the tank is closely related to external excitations. Therefore, a more careful evaluation of the hydrodynamics performance of a sloshing water storage tank under external excitation is required. Water 2020, 12, 2098; doi:10.3390/w12082098 www.mdpi.com/journal/water
Water 2020, 12, 2098 2 of 14 At first, researchers focused on the sloshing phenomena subject to a harmonic excitation [6–9]. As was shown, sloshing characteristics were influenced by tank parameters such as water depth [10], tank shape [7,11,12], baffle type [9,11,13–15], external excitation [6], and so on [16]. A series of analytical [15,17], numerical [10,18], and experimental [19,20] methods were established for solving the sloshing problem under different conditions. However, Chen et al. [21] compared the response of liquid tanks under harmonic excitations with those under the ground motion excitation, and they found that simple harmonic excitation cannot replace nonlinear seismic excitation for the seismic analysis of liquid tanks, because seismic excitation usually consists of a broadband frequency vibration, and harmonic excitation only contains a single frequency. The primary frequencies of the ground motion decrease with the increasing intensity of a seismic event. The frequencies of a strong earthquake are usually distributed across a lower range, which is similar to the natural frequencies of many large industrial tanks [22]. Therefore, the sloshing phenomena under various types of seismic excitation may differ. In order to improve the computational efficiency and reduce the costs, a small-scale geometric model was usually used on a tank whose characteristic length in the excitation direction was between 0.6 and 1 m [23,24]. However, the ground motion has not been proportionally scaled, along with an overestimated sloshing response estimated. Meanwhile, the filling levels of the tank in the previous study were usually selected to be at a shallow depth [25–27] (depth/tank’s length < 0.1) or near critical depth (depth/tank length ≈ 0.337) [25,28] to study the nonlinear sloshing phenomenon. The limited cases considering high filling level conditions focused on the problem of the impact of water on the tank roof under the large displacement [29]. Jin et al. [19] tested the sloshing response in a high filling level tank with filling depth(d)/tank length(L) = 0.5 by the experiments, and they found that the water motion tended to be linear in such a deep tank, which differed from the violent nonlinear sloshing in the shallow water tank. For city water storage tanks, the size is large, and the filling level is high. The load from the sudden ground movement will be the main threat to its safety. Unlike the long-term loads such as wind or waves in tuned liquid damper systems on high-rise buildings or the liquid tanks in ships, the seismic wave is a non-periodic impulse vibration with a broadband frequency characteristic. Under this condition, the motion response of the water in the container may differ from the previous studies. In this research, the liquid sloshing motion in a real-scale water storage tank was investigated under several selected ground motions, using the computational fluid dynamic (CFD) software—OpenFOAM® (Version: 1906, OpenCFD, Bracknell, UK) [30]. The high filling level, real-scale tank, and ground motion were used to distinguish the present water motion from previous sloshing studies in other fields. First, the numerical model and the governing equation were introduced. The problem of seismic response of the water tank was described in detail. Then, the numerical model was used to discuss the motion of the free surface in the water tank and the sloshing control effect by the damping plate after rigorous numerical verification. 2. Numerical Method and Model 2.1. Governing Equation Navier–Stokes equations [30] were used to describe the incompressible, viscous, water flows in the present numerical model. In the sloshing problem, the sloshing flow was usually assumed to be a laminar flow, and it can give an acceptable result when the free surface motion was small [10,16,31]. In this study, the laminar model was used to solve the governing equations below: ∂ui =0 (1) ∂xi ∂ui ∂u 1 ∂p µ ∂ ∂ui + ui i = − + + fbody (2) ∂t ∂x j ρ ∂xi ρ ∂x j ∂x j
Water 2020, 2020, 12, 12, 2098 x FOR PEER REVIEW 33 of of 14 The meaning of the variables in the above equation is as follows: ρ is the density of the water, ui The meaning represents of thecomponents the velocity variables ininthethe above equation i direction, xi is (i as follows: = x, ρ is the densityand y in two-dimensions of the water, x, y, z in u i represents the three-dimensions), velocity components in the i direction, x p is the pressure, μ is the dynamic viscosity, i (i = x, y in two-dimensions and x, and fbody represents the body forces, y, z in such as gravity. Thep Finite three-dimensions), is the pressure, µ is the dynamic Volume Method (FVM) was viscosity, used for and f bodydiscretization spatial represents theofbody forces, the partial such as gravity. The Finite Volume Method (FVM) was used for spatial discretization differential equations. The quantities of interest, e.g., the pressure and velocity of fluid, were stored of the partial differential equations. at the centroid The volumes. of control quantitiesThe of interest, e.g., the pressure volume-of-fluid and velocity (VoF) method of fluid, to was selected were storedthe capture at the freecentroid surface. of Thecontrol volumevolumes. fractionThe volume-of-fluid of the fluid was defined(VoF) in method was selected the transport equation:to capture the free surface. The volume fraction of the fluid was defined in the transport equation: ρ = ρα=w ater ρ ρ + +(1(1−−ααw ater ))ρρ air, ,v v==α α w ater α w ater v + (1 − α w) ater ) v air, + (1 − α v w ater v , (3) (3) water water water air water water water air water is where αwater isthe thevolume volumefraction fractionof of water water and and vv is is the kinematic viscosity. The volume fraction of following equation: water was expressed by the following equation: ∂ α∂α ∂ui ++ αα ∂ui = =0 (4) ∂ t∂t ∂ xi i 0 ∂x (4) The variable The variable α represents water α represents water when when its value is its value equal to is equal 1 and to 1 and the the interface interface of of water water and and air air when α ≈ 0.5. when α ≈ 0.5. 2.2. Numerical Model The sloshing model was established based on OpenFOAM (Version: 1906), and the results were solved through the interFoam solver. The solution process of the new interFoam solver is shown in Figure 1.1.The ThePIMPLE PIMPLE algorithm, algorithm, a combination a combination of (Pressure of PISO PISO (Pressure ImplicitImplicit with of with Splitting Splitting of Operator) Operator) and SIMPLE (Semi-Implicit Method for Pressure-Linked Equations), in and SIMPLE (Semi-Implicit Method for Pressure-Linked Equations), in Figure 1 was applied to solve the Figure 1 was applied to solve the pressure–velocity pressure–velocity coupling relationship.coupling relationship. More detail Morethe of the solver, detail of the conditions, boundary solver, the boundary and other conditions, setups and other can refer to thesetups can study previous refer to[18]. the previous The meshstudy near [18]. Thesurface the free mesh nearwasthe free surface refined was to improve refined to improve the accuracy of free surface capture. The 6 degree-of-freedom the accuracy of free surface capture. The 6 degree-of-freedom (6DoF) tank movements were imposed (6DoF) tank movements through were imposed a formatted throughofa time displacement formatted series displacement data. of time series data. Figure 1. Figure Solution process 1. Solution process of of the the interFoam interFoam solver. solver. 2.3. Problem Description 2.3. Problem Description To investigate the water motion in a real-scale tank, which was subjected to the ground motions, To investigate the water motion in a real-scale tank, which was subjected to the ground the present numerical model was validated first with experimental tests. The experimental water tank motions, the present numerical model was validated first with experimental tests. The experimental was 1 m (L) × 0.8 m (H) × 0.1 m (B) as shown in Figure 2, and the filling depth d/L was 0.5. The amplitude water tank was 1 m (L) × 0.8 m (H) × 0.1 m (B) as shown in Figure 2, and the filling depth d/L was 0.5. of horizontal displacement A/L was 0.0025, and the excitation frequency ω/ω1 = 0.996 in Figure 2b The amplitude of horizontal displacement A/L was 0.0025, and the excitation frequency ω/ω1 = 0.996 and ω/ω1 = 0.603 in Figure 2c (ω1 is the first-order natural frequency of the liquid tank). The detailed in Figure 2b and ω/ω1 = 0.603 in Figure 2c (ω1 is the first-order natural frequency of the liquid tank). experimental setup and the arrangement of the experimental system were the same as the author’s The detailed experimental setup and the arrangement of the experimental system were the same as previous experimental device, and there is no baffle installation in the validation test [19]. Then, the free the author’s previous experimental device, and there is no baffle installation in the validation test surface shape and the flow motion were compared carefully in Figure 2b,c. The heights of the free [19]. Then, the free surface shape and the flow motion were compared carefully in Figure 2b,c. The surface curves and the time history of the free surface elevation along the left tank wall are also shown heights of the free surface curves and the time history of the free surface elevation along the left tank in Figure 3 and validated based on the experimental result and theory model [32]. The uncertainty wall are also shown in Figure 3 and validated based on the experimental result and theory model analysis was conducted to obtain the standard error and confidence level of the experimental result. [32]. The uncertainty analysis was conducted to obtain the standard error and confidence level of the The numerical result fell within the 95% confidence interval. The theoretical results were a bit biased experimental result. The numerical result fell within the 95% confidence interval. The theoretical results were a bit biased after 14 s, which may be because it did not consider the viscosity and
Water 2020, 12, 2098 4 of 14 Water 2020, 12, x FOR PEER REVIEW 4 of 14 afterWater 14 s,2020, which may 12, x FOR beREVIEW PEER because it did not consider the viscosity and compressibility of the 4 of 14 fluid. In general, the error of the experimental tests was acceptable, and the result of compressibility of the fluid. In general, the error of the experimental tests was acceptable, and the the numerical model compressibility wasresult credible. of the fluid. In general, the error of the experimental tests was acceptable, and the of theFurthermore, numerical model the ability of the present was credible. modelthe Furthermore, to ability simulate strong of the nonlinear present modelwater motion to simulate was result also of the numerical verified with themodel was credible. experimental testFurthermore, of Faltinsen the etability al. of the [33] in present4. Figure model The to simulate tank’s internal strong nonlinear water motion was also verified with the experimental test of Faltinsen et al. [33] in strong nonlinear water motion was also verified with the experimental test of Faltinsen et al. [33] in dimensions Figure were 4. The 1.0 m tank’s × 0.98dimensions internal m × 0.1 m were 1.0 × (length × 0.98 m× ×breadth), m height 0.1 m (lengththe d/L was 0.4, × height and thethe × breadth), A/L Figure 4. The tank’s internal dimensions were 1.0 m × 0.98 m × 0.1 m (length × height × breadth), the was 0.01. The d/L goodthe agreements wereTheobtained in two sets were of tests. The present numerical using a d/Lwas was0.4,0.4,and and the A/L A/L was was 0.01. 0.01. The good agreements good agreements obtained were obtained in in two two sets sets of of tests. tests. TheThe laminar presentassumption presentnumerical can numericalusing be used usingaalaminar to analyze laminar assumption the assumption can sloshing canbebeusedproblem. usedtotoanalyze analyze thethe sloshing sloshing problem. problem. Figure 2. Free 2. 2.Free surface shapeofofsloshing sloshing water in a rectangular tank under horizontal harmonic Figure Figure Freesurface surfaceshape shape of sloshing water water in in aa rectangular tank rectangular tank under under horizontal horizontal harmonic harmonic excitation, (a) data acquisition system, (b) Resonant sloshing, ω/ω1 = 0.996, (c) non-resonant sloshing, excitation, (a) excitation, data acquisition system, (b) Resonant sloshing, ω/ω 1 = 0.996, (c) non-resonant sloshing, (a) data acquisition system, (b) Resonant sloshing, ω/ω1 = 0.996, (c) non-resonant sloshing, ω/ω1 = 0.603. ω/ωω/ω= 0.603. 1 1 = 0.603. Figure 3. The Figure validation 3. The validationofof thethepresent presentnumerical modelwith numerical model withexperimental experimental teststests [19] [19] and and theoretical theoretical solution solution ω/ωω/ω [32],[32], 1 = 10.996, = 0.996, A/L==0.0025, A/L 0.0025, d/L = 0.5.(a) = 0.5. (a)Uncertainty Uncertainty analysis analysis of three of three experimental experimental tests, tests, theFigure error bars the error indicated bars a indicated Standard a Error Standard of Error time of (X-error) time and (X-error) andheight (Y-error) height (Y-error) of the of the 3. The validation of the present numerical model with experimental tests [19] and theoretical free free surface surface wave. wave. (b)solution Red (b) shallow Red shallow area area represented represented the the prediction prediction limitlimit of of the the average average experimental experimental result result [32], ω/ω1 = 0.996, A/L = 0.0025, d/L = 0.5. (a) Uncertainty analysis of three experimental tests, at at aa 95% 95% confidenceconfidence the errorlevel. level. bars indicated a Standard Error of time (X-error) and height (Y-error) of the free surface wave. (b) Red shallow area represented the prediction limit of the average experimental result at a 95% confidence level.
Water 2020, 12, x FOR PEER REVIEW 5 of 14 Water 2020, 12, 2098 5 of 14 Water 2020, 12, x FOR PEER REVIEW 5 of 14 Figure 4. Flow motion through the vertical slot baffle in Faltinsen’s experimental tests [33], τ is the porosity of the baffle, (a) τ = 0.085, ω/ω1 = 1.328, Time = 14 s, (b) τ = 0.527, ω/ω1 = 0.96, Time = 46 s. Figure 4.4. Flow Figure Flow motion motion through through the the vertical vertical slot slot baffle baffle in in Faltinsen’s Faltinsen’s experimental experimental tests tests [33], [33], ττ is is the the porosity porosityof ofthe thebaffle, (a)ττ== 0.085, baffle,(a) 0.085, ω/ω ω/ω11 = = 1.328, Time = 14 s, = 14 (b) ττ ==0.527, s, (b) ω/ω1 1= = 0.527,ω/ω 0.96, 0.96, Time= = Time 4646 s. s. Then, a real-scale water tank in Haroun [34] was selected as the baseline structure for this study. This tankThen, was located in Los Angeles, which is a city with potential the earthquakes risk [35]. The study. tank Then, aa real-scale real-scale waterwater tank tank in in Haroun Haroun [34] [34] was was selected selected as as the baseline structure baseline structure for this for this study. geometry This is shown in Figure 5, with 18 m (Diameter (D)) × 18.25 m (Height′(H′)). The filling depth d This tank tank waswas located located in inLosLosAngeles, Angeles, which which isisaacity citywithwithpotential potentialearthquakes earthquakes risk risk[35]. [35]. TheThe tank tank was 10.8 m (60% D), and then the tank can be regarded as a slender [36] or deep 0 (H )).water 0 tank (2d/D >d geometry geometry is is shown shown in inFigure Figure5,5,with with18 18mm(Diameter (Diameter(D)) (D))××18.2518.25mm(Height (Height′(H′)). The The filling filling depth depth d 1). This filling level was larger than the value of d/D = 0.4, and therefore, the wave motion resembles > 1).> was was10.810.8m (60%D), m(60% D),and andthen thenthe thetank tankcan canbebe regarded regarded as as a slender a slender [36][36] or deep or deep water water tank (2d/D tank (2d/D aThis standing filling wave level with was the largerlargest than free the surface value ofelevations d/D = 0.4, atand the tank walls the therefore, [37].wave The Froude motion number resembles is 1). This filling level was larger than the value of d/D = 0.4, and therefore, the wave motion resembles the only dimensionless aa standing number largesttofree be considered if thereatisthe a scaled model[37]. used. TheIn CFD analysis, standing wave wave with with the the largest free surface elevations surface elevations tankwalls at the tank walls [37]. The Froude Froude number number is simplified is the only assumptions dimensionless and number models to be are usually considered if required there is a to scaled makemodel the calculation used. In CFD process analysis, the only dimensionless number to be considered if there is a scaled model used. In CFD analysis, economically simplified viable. Therefore, a two-dimensional (2D)to Oxymakesection of the cylindrical tank was simplifiedassumptions assumptions andand models models are usually required are usually required the to calculation make the process calculation economically process extracted viable. to build Therefore, a numerical a two-dimensional water tank. The size (2D) Oxy section (2D) of the numerical of theOxy cylindrical tank was the same as the reala economically viable. Therefore, a two-dimensional section tank of thewascylindrical extracted to build tank was water numericaltank in X water and Y tank. directions. The size The of the Z direction numerical in tankthe numerical was the same model as thewasreala symmetry water tank plane. in X The and Y extracted to build a numerical water tank. The size of the numerical tank was the same as the real mesh dependence directions. The Z was tested direction in to ensure the numerical thatmodel the present was a mesh symmetry size can plane.capture The the sloshing mesh dependence surface was water tank in X and Y directions. The Z direction in the numerical model was a symmetry plane. The well testedin toTable ensure1. Finally, that thethe medium present mesh size with Δx =the 0.15 m, Δy =surface 0.05 mwell wasin selected, Table 1.and the mesh dependence was tested to mesh ensuresize thatcan thecapture present mesh sloshing size can capture the sloshing Finally, surface mesh near the free water surface was refined locally. Two well-studied ground motions, the 1940 the wellmedium in Tablemesh size with 1. Finally, the ∆x medium= 0.15 mesh m, ∆ysize = 0.05withm Δx was= selected, 0.15 m, Δy and the mesh = 0.05 m was near the freeand selected, waterthe Imperial surface Valley was (IV) and refined 1971Two locally. San well-studied Fernando (SF)ground earthquakes motions, [38],thewere 1940 selected Imperial forValley the following (IV) and mesh near the free water surface was refined locally. Two well-studied ground motions, the 1940 analysis. 1971 San They Fernandotransferred (SF) a nonlinear earthquakes vibration [38], were(SF) with the selected for broadband the following frequency analysis. to the transferred water tank.a Imperial Valley (IV) and 1971 San Fernando earthquakes [38], were selectedThey for the following The strongvibration nonlinear vibrationwith of the theIV earthquake lasted a to long time, while tank.the SFstrong earthquake hadofstrong analysis. They transferred a broadband nonlinear vibrationfrequency withthe thewater broadband The frequency vibration to the water the IV tank. instantaneous earthquake vertical displacement and short duration. Both the ground motions in the longitudinal The strong lasted a long vibration of time, the IV while the SF earthquake earthquake lasted a long had time, strongwhile instantaneous vertical displacement the SF earthquake had strong (X and direction) short and vertical duration. Both (Y direction) the ground directions motions in thewere considered, longitudinal (X instead ofand direction) the vertical condition (Y in which direction) instantaneous vertical displacement and short duration. Both the ground motions in the longitudinal only longitudinal directions were displacement considered, was applied in previous studiesonly[23,24]. By the way, the locationwas of (X direction) and vertical (Y instead direction) of directions the condition wereinconsidered, which longitudinal instead displacement of the condition in which the SF applied earthquake is close in previousdisplacement to studies [23,24]. the water tank in Haroun. Therefore, the water motion under these only longitudinal wasByapplied the way, inthe location previous of the [23,24]. studies SF earthquake By the way, is close thetolocation the water of different tank in excitations Haroun. might the Therefore, performwater differently. motion under Each these of the ground different motionsmight excitations was scaled perform to differently. the same the SF earthquake is close to the water tank in Haroun. Therefore, the water motion under these peak Each ground of the acceleration ground motions (PGA) wasofscaled0.5 g so to that the samethey represented the same earthquake intensity. The different excitations might perform differently. Eachpeak of theground ground acceleration motions was (PGA)scaled of 0.5 to g sosame the that information they of the two scaled earthquake events is listed in Table 2, and the scaled ground motions peakrepresented the same (PGA) ground acceleration earthquake of 0.5intensity. g so that The theyinformation representedofthe thesame two earthquake scaled earthquake intensity. events The are is shown listed in in Figure Table 2, 6. the scaled ground motions are shown in Figure 6. and information of the two scaled earthquake events is listed in Table 2, and the scaled ground motions are shown in Figure 6. Thegeometry Figure5.5.The Figure geometryofofthe thewater waterstorage storagetank. tank. Figure 5. The geometry of the water storage tank.
Water 2020, 12, x FOR PEER REVIEW 6 of 14 Table 1. Grid dependence of the free surface elevation at the right side wall under the Imperial Valley (IV) earthquake. Water 2020, 12, 2098 6 of 14 Maximum Calculation Averaged Free Surface Peaks at Relative Mesh Description Size (x × y) Time (s) Right Side Wall (x = 9 m) Difference 1Table 1. Grid Fine 0.075 × 0.025 3391 0.1839 m - dependence of the free surface elevation at the right side wall under the Imperial Valley 2(IV) earthquake. Medium (used) 0.15 × 0.05 464 0.1746 m 5% 3 Coarse 0.3 × 0.1 88 0.1580 m 14% Maximum Calculation Averaged Free Surface Peaks Relative Mesh Description Table 2. Information of twoSize (x × y)groundTime strong (s) motions. at Right PGA: peakSide ground = 9 m) Wall (xacceleration, Difference SF: San Fernando. 1 Fine 0.075 × 0.025 3391 0.1839 m - 2 Medium (used) 0.15 × 0.05 464 0.1746 m 5% 3 Coarse 0.3 × 0.1 88 0.1580 Strong Motion Duration Earthquake Event Scaled PGA (g) Scale Factor Scaled PGD* (m) m 14% (s) Longitudinal: Longitudinal: Table 2. Information of two strong ground motions. PGA: peak ground acceleration, SF: San Fernando. IV 0.5zhiweiVertical: 1.78 0.154zhiweiVertical: 30 Earthquake Event 0.317 Scaled PGA (g) Scale Factor 0.048 Scaled PGD* (m) Strong Motion Duration (s) Longitudinal: Longitudinal: 0.5 Longitudinal: Longitudinal: 0.154 SF IV 0.5zhiweiVertical: 1.78 0.41 0.160zhiweiVertical: 30 18 Vertical: 0.317 Vertical: 0.048 0.282 Longitudinal: 0.5 0.120 Longitudinal: 0.160 SF 0.41 18 Vertical: 0.282 Vertical: 0.120 PGD*: peak ground displacement. PGD*: peak ground displacement. Figure 6. Acceleration and displacement of two selected earthquakes, (a) the scaled acceleration and the displacement of the Imperial Valley 1940 earthquake, (b) the scaled acceleration and the displacement of the San Fernando 1971 earthquake.
Water 2020, 12, x FOR PEER REVIEW 7 of 14 Figure 6. Acceleration and displacement of two selected earthquakes, (a) the scaled acceleration and the displacement Figure of and 6. Acceleration the displacement Imperial Valley 1940 of two earthquake, selected (b) the earthquakes, (a) scaled acceleration the scaled andand acceleration the displacement of the San Fernando 1971 earthquake. the displacement of the Imperial Valley 1940 earthquake, (b) the scaled acceleration and the Water 2020, 12, 2098 of the San Fernando 1971 earthquake. displacement 7 of 14 3. Results and Discussion 3. Results and Discussion 3.3.1. Results and Discussion Comparison of Water Motion between Two-Dimensional and Three-Dimensional Results 3.1. Comparison 3.1. In order to Comparison of Water of make Waterthe Motion betweenprocess calculation Motion between Two-Dimensional economical, Two-Dimensional andthe and Three-Dimensional Oxy section wasResults Three-Dimensional Results extracted to study the water sloshing In order order in thethe to make make tank under seismic calculation process excitation. economical,However, the Oxy Oxy in section case thewas 2D extracted simulationtocan be used study the In to the calculation process economical, the section was extracted to study the instead water of the sloshing real in the3D status, tank the under comparison seismic of water excitation. motion However, between in case the the 2D 2D and simulation3D problems can be was used water sloshing in the tank under seismic excitation. However, in case the 2D simulation can be used conducted. instead theAreal of the similar real trend the 3D status, status, can comparison be seen in Figure 7. The of water water free between motion surface atthe the2DOxyand(Z3D3D= 0) section in problems wasthe instead of 3D the comparison of motion between the 2D and problems was 3D simulation conducted. A coincided with the 2D result. Meanwhile, it can be seen that the free surface elevation conducted. A similar similar trend trend can be seen can be seen in in Figure Figure 7. 7. The The free free surface surface at at the the Oxy Oxy (Z (Z = = 0) section in 0) section in the the 3Ddecreased simulation along the Z direction coincided with the from 2D 0 to ±9 result. m (Oyz section Meanwhile, it can of the be seen tank) that in the the free 3D model, surface which is elevation 3D simulation coincided with the 2D result. Meanwhile, it can be seen that the free surface elevation different from decreased alongthe theprevious Z directionresearch direction from 0in0 toa cube to ±9 m tank [10]. They showed a similar sloshing model,response isin decreased along the Z from ±9 m (Oyz section (Oyz section of the tank) of the tank) in the in the 3D3D model, which is which the Z direction. different from from the This is the previous because previous research we research inused a cylindrical in aa cube cube tank tank [10]. tank, [10]. They and They showed the side wall showed aa similar of the similar sloshing tank was a sloshing response curved response inin different surface. the Z Further direction. investigation This is because of the we usedtwo a models is supplied cylindrical tank, and inthe Figure side 8. of the tank was a curved wall the Z direction. This is because we used a cylindrical tank, and the side wall of the tank was a curved surface. Further surface. Further investigation investigation of of the the two two models models is is supplied supplied in in Figure Figure 8. 8. Figure 7. Free surface shape of the sloshing in the water tank under the IV earthquake, (a) 2D case, t = Figure s, 10.25 Figure 7. (b) 7. Free Free3D case, tshape surface surface = 10.25 shape s.the ofof thesloshing sloshingininthe thewater water tank tank under under thethe IVIV earthquake, earthquake, (a) (a) 2D2D case, case, t= = 10.25 t10.25 s, (b) s, (b) 3D 3D case, case, t = 10.25 t = 10.25 s. s. Figure 8. Free surface elevations at the right side wall. Figure 8. Free surface elevations at the right side wall. The maximum free surface Figure elevation appeared 8. Free surface at the elevations Oxyright at the section side of the tank, as seen in Figure 8. wall. In thisThe maximum study, the freefree surface surface on elevation appeared the Oxy section wasat extracted the Oxy section to showof the thetank, water assloshing seen in Figure in the8. In this tank The study, under the free surface seismic excitation. maximum free surfaceThison the Oxy section resultappeared elevation was extracted usually indicated at the Oxythe to show most of section the water dangerous sloshing the tank, section in the of Figure as seen in tank the tank.8. under Therefore,seismic in excitation. order to save This time result and usually calculation indicated costs, the the watermost dangerous movement in section the In this study, the free surface on the Oxy section was extracted to show the water sloshing in the tank most of the dangeroustank. Therefore, section under was in seismic order calculated to here excitation. saveThistime mainly and result calculation based on the usually costs, the thewater 2D simulation. indicated most movement The insection free surface dangerous the most of dangerous shape andtank. the the section time was history Therefore, calculated inof elevation order to savehere mainly between time and based on the thecalculation 2D 2D and 3Dcosts, simulation. simulation the water The free are movement surface further shown in the shape in most and Figures 8the andtime dangerous 9. history They of elevation indicated that thebetween 2D the results 2D were and 3D simulation acceptable. are Therefore, further the shown motion in Figures response section was calculated here mainly based on the 2D simulation. The free surface shape and the time of 8 and water 9. and They the conclusions drawn from history of elevation it should between the 2D be and meaningful. 3D simulation are further shown in Figures 8 and 9. They
Water 2020, 12, x FOR PEER REVIEW 8 of 14 Water 2020, 12, x FOR PEER REVIEW 8 of 14 indicated that the 2D results were acceptable. Therefore, the motion response of water and the Water 2020, 12, indicated conclusions 2098 that the 2D drawn results from were it should meaningful.Therefore, the motion response of water and8 ofthe beacceptable. 14 conclusions drawn from it should be meaningful. Figure 9. Free surface response at selected moments. Figure 9. Free surface response at selected moments. Figure 9. Free surface response at selected moments. 3.2. Free 3.2. Free Surface Surface Motion Motion in in the the High High Filling Filling Depth Depth Water Water Tank Tankunder underSeismic SeismicExcitation Excitation 3.2. Free Surface Motion in the High Filling Depth Water Tank under Seismic Excitation From Figure From Figure6,6,the the largest largest longitudinal longitudinal andand vertical vertical PGDs PGDs appeared appeared in thein the10first first s of 10 the sground of the ground From Figure motions. 6, Duringthe largest this longitudinal stage, the shapes and of vertical the free PGDs surface appeared at the motions. During this stage, the shapes of the free surface at the 2 s, 4 s, 6 s, 8 s, and 10 s and2 s, 4in s, the 6 s, first 8 s, 10 and s 10 of the s and the ground the Fast Fast motions. FourierFourier During Transfer Transfer (FFT)this stage, (FFT) the shapes of twoofof amplitudes amplitudes the ground two ground free surface motions at shown motions are theare 2 s,shown 4 s, in 6 s,in8 10. Figure s, and FigureThe1010.s and The results the Fast results Fourier showed Transfer that the (FFT) response amplitudes of the of water two ground reached the motions maximum are showed that the response of the water reached the maximum displacement of the tank. Although the shown displacement in Figure of 10. the The tank. results Although maximum showed the that the instantaneous maximum instantaneous response displacement of the of water displacement the reachedof the SF earthquake theSFmaximum earthquake was larger (seedisplacement was Tablelarger offree (see 1), the the Tabletank. 1), liquid Although the free the liquid maximum motion instantaneous caused by it was displacement not significantly of the more SF earthquake violent than motion caused by it was not significantly more violent than that of the IV earthquake. The maximum was that oflarger the IV (see Table earthquake. 1), the Thefree free liquid maximum surface motion elevations caused free surface of the twoby itearthquakes was notofsignificantly elevations the more two earthquakes reached 11.20 mviolent thanm,that reached and 11.19 of the 11.20 m IV respectively. andearthquake. The11.19 ratio m, of The maximum respectively. Thefree ratiosurface of the elevations free surface of the elevation twoto earthquakes the original reached water level the free surface elevation to the original water level was only 3.7% for the IV earthquake and 3.6% for 11.20 was m onlyand 3.7%11.19 for m, the respectively. IV earthquake the The SF earthquake.andratio 3.6%offor There the is free the no SFsurface elevation earthquake. significant There difference to isthe here. nooriginal water significant level was difference only 3.7% for the here. IV earthquake and 3.6% for the SF earthquake. There is no significant difference here. Figure 10. Free surface response at selected moments, (a) the free surface response under the Imperial Valley 1940 earthquake, (b) the free surface response under the San Fernando 1971 earthquake.
Imperial Valley 1940 earthquake, (b) the free surface response under the San Fernando 1971 earthquake. The free surface shapes are shown in Figure 10, indicating that the location of the largest node of water vibration is different. The nodes in IV are located around 1/3D and 2/3D, and the nodes in Water 2020, 12, 2098 9 of 14 SF are located at the side wall. They corresponded to the first and third modes sloshing in the water tank, respectively [39]. Based on the Fast Fourier Transfer (FFT), the seismic excitations were transferredTheto free thesurface shapes domain, frequency are shownand in Figure 10, indicating the first that thefrequencies three natural location of the (ωi,largest i = 1,node 2, 3)ofwere marked. The results showed that the primary frequencies of SF and IV were close to ωSF water vibration is different. The nodes in IV are located around 1/3D and 2/3D, and the nodes in are 1 and ω3, located at the side wall. They corresponded to the first and third modes sloshing in the water tank, respectively. Therefore, the corresponding sloshing modes were excited. On the other hand, the odd respectively [39]. Based on the Fast Fourier Transfer (FFT), the seismic excitations were transferred to resonance modes of sloshing are (n = 1, 3, …) usually activated by the anti-symmetric motion (sway the frequency domain, and the first three natural frequencies (ωi, i = 1, 2, 3) were marked. The results in the horizontal showed that the direction) of the container, primary frequencies of SF and IVand wereeven close the to ω1resonance modes (nTherefore, and ω3 , respectively. = 2, 4, …) corresponded to the symmetric motion (heavy in the vertical direction). the corresponding sloshing modes were excited. On the other hand, the odd resonance modes The FFT results in Figure of 10 indicated thatare sloshing the(nresonance = 1, 3, . . . )sloshing is more likely usually activated by the to occur under motion anti-symmetric the IV earthquake. (sway in the horizontal The envelopes direction) of the maximum of the container, and even thefreeresonance surface modes revealed(n =that . . . )effects 2, 4,the of water corresponded to on the the tank walls symmetric were similar (Figure 11), although the excitations of the ground motion were irregular and motion (heavy in the vertical direction). The FFT results in Figure 10 indicated that the resonance sloshing is asymmetric. more likely to Meanwhile, theoccur under the maximum IV surface free earthquake.elevation appeared near the side wall, and the The envelopes of the maximum free surface minimum point was located at the center of the still water level. revealed that the The effects of water level high-water on theattank the walls tank wall were similar (Figure 11), although the excitations of the ground motion of the water tank is also usually the cause of the destruction and overturning of the tank. The were irregular and asymmetric. Meanwhile, the maximum free surface elevation appeared near the side wall, and the minimum point maximum rate of free surface elevation was 6.58% for the IV earthquake and 8.20% for the SF was located at the center of the still water level. The high-water level at the tank wall of the water earthquake. These results mean that earthquakes with large instantaneous displacements, such as tank is also usually the cause of the destruction and overturning of the tank. The maximum rate of the SF earthquake, free may lead surface elevation to more was 6.58% for dangerous situations. the IV earthquake This for and 8.20% wasthe inconsistent SF earthquake. with the conclusion These results reflected meanin theearthquakes that response of withthelarge water motion during instantaneous the first 10 displacements, suchs when as the aSFlarge groundmay earthquake, displacement lead to occurred. Therefore,situations. more dangerous the time This history wasof the free surface inconsistent with theelevation conclusionatreflected the right sideresponse in the wall is of shown the in Figure 12 motion water to helpduring understand the firstthe 10 sabove when aphenomenon. Figure 12 shows large ground displacement thatTherefore, occurred. the sloshing was not the time fullyhistory excitedofinthe thefree early stageelevation surface of the earthquake. The wall at the right side maximum is shown free in surface Figure 12 response did not appear to help understand thestage at the abovewhenphenomenon. the maximumFigure 12ground shows that the sloshing occurred, displacement was not fully andexcited in the early the sloshing stage of phenomenon the earthquake. The maximum free surface response did not appear continued and kept growing, despite the large ground displacement having passed. The elevation at the stage when the maximum groundafter decreased displacement 10 s in theoccurred, and the sloshing SF earthquake event.phenomenon The water kept continued sloshing and stably kept growing, in the IV despite the earthquake large ground displacement having passed. The elevation decreased after 10 s in the SF earthquake event until a new seismic pulse peak appeared, and the elevation increased again. The above results event. The water kept sloshing stably in the IV earthquake event until a new seismic pulse peak indicated that the sloshing excited by the seismic motion was hysteretic compared with the ground appeared, and the elevation increased again. The above results indicated that the sloshing excited by motion. Therefore, the water storage tank still faced the threat of collapse, although the violent the seismic motion was hysteretic compared with the ground motion. Therefore, the water storage ground tankmotion still facedpassed. the threat of collapse, although the violent ground motion passed. Figure 11. The maximum free surface envelope under two different ground motions. Figure 11. The maximum free surface envelope under two different ground motions.
Water 2020, 12, 2098 10 of 14 Water 2020, 12, x FOR PEER REVIEW 10 of 14 Figure 12. Free surface elevations at right side wall. 3.3. Seismic Design of the Water Storage Tank and the Anti-Sloshing Ability of the Damping Baffle 12. Free surface elevations at right side wall. Even a short-term seismicFigure pulse Figure 12.will Free cause continuous surface elevations sloshing at right side wall. in the water storage tank and bring a sloshing load, which delayed more than the ground motion. 3.3. Seismic Design of the Water Storage Tank and the Anti-Sloshing Ability of the For Dampingthe Baffle safety design of the 3.3. Seismic Design of the Water Storage Tank and the Anti-Sloshing Ability of the Damping Baffle water tank in Evenearthquake-prone a short-term seismicareas, a well-studied pulse will cause continuous vertical sloshingdamping baffle in the water (seetank storage Figure and 13) was used to test Even bringits a short-term suppression a sloshing seismic pulse on sloshing, load, which delayed more will such cause thanasthecontinuous [15,20,40,41]. sloshing ground motion.The in the For height water the safety storage ofdesign the baffle tanka and = 2/3d. The of the water mesh around the baffle was refined. Figure 14 gives the free surface elevations at the righttheside wall bring tank ina sloshing load, earthquake-prone which areas, delayed a more well-studied than the vertical ground damping motion. baffle (seeFor the Figure safety 13) wasdesign used of to test water its tank in earthquake-prone suppression on sloshing, such as areas, a well-studied [15,20,40,41]. vertical The height damping of the baffle abaffle = 2/3d.(see TheFigure mesh 13) was around in the cases of tanks with and on without the damping baffle.The The results showed that the vertical the baffle was refined. Figure 14 gives the free surface elevations at the right side wall in the casesThe used to test its suppression sloshing, such as [15,20,40,41]. height of the baffle a = 2/3d. of dampingtanks baffle mesh with had aroundandthea baffle better without was the effect damping onbaffle. refined. the free Figure surface 14 gives The the results elevations free showed surface that the at thedamping elevations vertical atside wall, the right under side baffle wall had a the SF earthquake. in theeffect better casesonofthe tanks freewith andelevations surface without at thethe damping side wall,baffle. underThe the results showed that the vertical SF earthquake. damping baffle had a better effect on the free surface elevations at the side wall, under the SF earthquake. Figure 13. Location of the damping baffle in the water tank and mesh geometry. 13. Location of the damping baffle in the water tank and mesh geometry. Figure Figure 13. Location of the damping baffle in the water tank and mesh geometry. On the other hand, the sloshing pressure on the two measuring points with and without the damping baffle was compared. The two measuring points were located near the bottom and the free surface of the water tank, which were 1 m and 10 m away from the bottom, respectively. Then, the pressure variation at these two points is shown in Figure 15, and the sloshing pressures were normalized by p/ρgh-1 to express the fluctuation of sloshing pressure. Here, the ρgh was the hydrostatic pressure at the selected points. The results showed that the pressure variation ratio near the water surface was larger than that in the bottom area. The damping baffle had a significant suppression effect on the sloshing pressure near the free liquid surface, but this only occurred after the violent ground motion passed. The pressure and free surface elevation had similar trends due to the seismic excitation. With the damping baffle, the maximum response of the sloshing surface and the pressure at the selected points P1 and P2 were suppressed by 16.8%, 5.0%, and 3.5% under the IV earthquake and 37.2%, 0.5%, and 4.2% for the SF earthquake. Then, the conclusion can be drawn that the suppression of sloshing pressure by the vertical damping baffle was limited under the nonlinear seismic excitation, although it can suppress the water motion well. That is probably because the vertical baffle suppressed the violent sloshing through its function of resonant frequency tuning. Since the nonlinear seismic excitation and the structural differences in size and the filling level may cause the different pressure response and the water motion, the results of the baffle configuration in the previous sloshing study
Water 2020, 12, 2098 11 of 14 cannot be applied directly to the seismic design of the tank. Therefore, analysis of the water motion Water 2020, 12, x FOR PEER REVIEW 11 of 14 and pressure within a water storage tank under an earthquake load is still needed. Figure 14. The suppression effect of the vertical damping baffle on sloshing water, (a) the free surface elevation under the Imperial Valley 1940 earthquake, (b) the free surface elevation under the San Fernando 1971 earthquake. On the other hand, the sloshing pressure on the two measuring points with and without the damping baffle was compared. The two measuring points were located near the bottom and the free surface of the water tank, which were 1 m and 10 m away from the bottom, respectively. Then, the pressure variation at these two points is shown in Figure 15, and the sloshing pressures were normalized by p/ρgh-1 to express the fluctuation of sloshing pressure. Here, the ρgh was the hydrostatic pressure at the selected points. The results showed that the pressure variation ratio near the water surface was larger than that in the bottom area. The damping baffle had a significant Figure 14. suppression Theon effect suppression effect the sloshing of the vertical pressure near thedamping baffle free liquid on sloshing surface, water, but this only(a) the free after occurred Figure 14. The suppression effect of the vertical damping baffle on sloshing water, (a) the free surface the violent ground motion passed. The pressure and free surface elevation had similar trendsthe surface elevation under the Imperial Valley 1940 earthquake, (b) the free surface elevation under due to elevation under the Imperial Valley 1940 earthquake, (b) the free surface elevation under the San San Fernando the seismic 1971 earthquake. excitation. Fernando 1971 earthquake. On the other hand, the sloshing pressure on the two measuring points with and without the damping baffle was compared. The two measuring points were located near the bottom and the free surface of the water tank, which were 1 m and 10 m away from the bottom, respectively. Then, the pressure variation at these two points is shown in Figure 15, and the sloshing pressures were normalized by p/ρgh-1 to express the fluctuation of sloshing pressure. Here, the ρgh was the hydrostatic pressure at the selected points. The results showed that the pressure variation ratio near the water surface was larger than that in the bottom area. The damping baffle had a significant suppression effect on the sloshing pressure near the free liquid surface, but this only occurred after the violent ground motion passed. The pressure and free surface elevation had similar trends due to the seismic excitation. Figure 15. Figure The fluctuation 15. The fluctuation of of sloshing sloshing pressure pressure at at selected selected points. points. 4. Conclusions The water motion in a real-scale water storage tank under two well-studied ground motions were investigated based on the OpenFOAM in this study. The experimental tests were conducted for validation of the present numerical model. The larger tank size, the high filling level, and the nonlinear seismic excitation were considered in this research. Other than the previous studies on sloshing in Figure 15. The fluctuation of sloshing pressure at selected points.
Water 2020, 12, 2098 12 of 14 a rectangular water tank, the results under the current conditions were slightly different in terms of baffle configuration design, pressure response, and water sloshing. (1) A comparison between 2D and 3D results of the water sloshing in a cylindrical tank was conducted. The 2D analysis could be used to predict the water sloshing response in a cylindrical tank. The Oxy section gave the maximum free surface elevation of the sloshing, and the most dangerous condition can be covered. (2) Due to the huge size of the water tank and the large mass of the filled water, the free surface motion was small, even under the strong ground motion. The maximum free surface elevation did not exceed 10%. (3) Similar to the response under the harmonic excitation, the free surface motion still satisfied the sloshing modal characteristic under seismic excitation. The maximum free surface elevation appeared at the side wall, and there were two nodes when the seismic frequency was close to the third-order natural frequency of the water tank. (4) In addition, the water motion was hysteretic compared with the ground motion. The maximum free surface elevation appeared after the seismic wave passed instead of the seismic wave was passing. Meanwhile, the pressure response was different, which kept decreasing after the strong seismic wave passed. (5) The effect of the well-used vertical damping baffle on the suppression of sloshing pressure was limited when the strong ground motion was passing. Further study about the seismic design of the water storage tank is still needed. Author Contributions: Writing—original draft, H.J.; Writing—review and editing, R.S. and Y.L. All authors have read and agreed to the published version of the manuscript. Funding: This research was funded by the Natural Science Foundation of Zhejiang, grant number LQ19E090005, the Natural Science Foundation of Ningbo, grant number 2019A610164 and National Natural Science Foundation of China, grant number 51605431. Conflicts of Interest: The authors declare no conflict of interest. References 1. Soroushnia, S.; Tafreshi, S.T.; Omidinasab, F.; Beheshtian, N.; Soroushnia, S. Seismic performance of RC elevated water tanks with frame staging and exhibition damage pattern. Procedia Eng. 2011, 14, 3076–3087. [CrossRef] 2. Korkmaz, K.A.; Sari, A.; Carhoglu, A.I. Seismic risk assessment of storage tanks in Turkish industrial facilities. J. Loss Prev. Process Ind. 2011, 24, 314–320. [CrossRef] 3. Vakilaadsarabi, A.; Miyajima, M.; Murata, K. Study of the Sloshing of Water Reservoirs and Tanks due to Long Period and Long Duration Seismic Motions. In Proceedings of the 15th World Conference on Earthquake Engineering, Lisbon, Portugal, 24–28 September 2012; pp. 1–10. 4. Zama, S.; Nishi, H.; Yamada, M.; Hatayama, K. Damage of Oil Storage Tanks Caused by Liquid Sloshing in the 2003 Tokachi Oki Earthquake and Revision of Design Spectra in the Long-Period Range. In Proceedings of the 14th World Conference on Earthquake Engineering, Beijing, China, 12–17 October 2008; pp. 1–8. 5. Faltinsen, O.M.; Timokha, A.N. Sloshing; Cambridge University Press: Cambridge, UK, 2009. 6. Frandsen, J.B. Sloshing motions in excited tanks. J. Comput. Phys. 2004, 196, 53–87. [CrossRef] 7. Faltinsen, O.M.; Timokha, A.N. An adaptive multimodal approach to nonlinear sloshing in a rectangular tank. J. Fluid Mech. 2001, 432, 167–200. [CrossRef] 8. Virella, J.C.; Prato, C.A.; Godoy, L.A. Linear and nonlinear 2D finite element analysis of sloshing modes and pressures in rectangular tanks subject to horizontal harmonic motions. J. Sound Vib. 2008, 312, 442–460. [CrossRef] 9. Gavrilyuk, I.; Lukovsky, I.; Trotsenko, Y.; Timokha, A. Sloshing in a vertical circular cylindrical tank with an annular baffle. Part 1. Linear fundamental solutions. J. Eng. Math. 2006, 54, 71–88. [CrossRef] 10. Chen, Y.; Xue, M.A. Numerical simulation of liquid sloshing with different filling levels using OpenFOAM and experimental validation. Water 2018, 10, 1752. [CrossRef]
Water 2020, 12, 2098 13 of 14 11. Akyldz, H.; Erdem Ünal, N.; Aksoy, H. An experimental investigation of the effects of the ring baffles on liquid sloshing in a rigid cylindrical tank. Ocean Eng. 2013, 59, 190–197. [CrossRef] 12. Faltinsen, O.M.; Timokha, A.N. Analytically approximate natural sloshing modes for a spherical tank shape. J. Fluid Mech. 2012, 703, 391–401. [CrossRef] 13. Isaacson, M.; Premasiri, S. Hydrodynamic damping due to baffles in a rectangular tank. Can. J. Civ. Eng. 2001, 28, 608–616. [CrossRef] 14. Biswal, K.C.; Bhattacharyya, S.K.; Sinha, P.K. Non-linear sloshing in partially liquid filled containers with baffles. Int. J. Numer. Methods Eng. 2006, 68, 317–337. [CrossRef] 15. Faltinsen, O.M.; Firoozkoohi, R.; Timokha, A.N. Analytical modeling of liquid sloshing in a two-dimensional rectangular tank with a slat screen. J. Eng. Math. 2011, 70, 93–109. [CrossRef] 16. Lee, D.H.; Kim, M.H.; Kwon, S.H.; Kim, J.W.; Lee, Y.B. A parametric sensitivity study on LNG tank sloshing loads by numerical simulations. Ocean Eng. 2007, 34, 3–9. [CrossRef] 17. Jin, H.; Liu, Y.; Song, R.; Liu, Y. Analytical Study on the Effect of a Horizontal Perforated Plate on Sloshing Motion in a Rectangular Tank. J. Offshore Mech. Arct. Eng. 2020, 142. [CrossRef] 18. Jin, H.; Liu, Y.; Li, H.; Fu, Q. Numerical analysis of the flow field in a sloshing tank with a horizontal perforated plate. J. Ocean Univ. China 2017, 16, 575–584. [CrossRef] 19. Jin, H.; Liu, Y.; Li, H.J. Experimental study on sloshing in a tank with an inner horizontal perforated plate. Ocean Eng. 2014, 82, 75–84. [CrossRef] 20. Xue, M.A.; Zheng, J.; Lin, P.; Yuan, X. Experimental study on vertical baffles of different configurations in suppressing sloshing pressure. Ocean Eng. 2017, 136, 178–189. [CrossRef] 21. Chen, W.; Haroun, M.A.; Liu, F. Large amplitude liquid sloshing in seismically excited tanks. Earthq. Eng. Struct. Dyn. 1996, 25, 653–669. [CrossRef] 22. Huerta-Lopez, C.I.; Shin, Y.; Powers, E.J.; Roesset, J.M. Time-frequency analysis of earthquake records. In Proceedings of the 12th World Conference on Earthquake Engineering, Auckland, New Zealand, 30 January–4 February 2000; pp. 1–8. 23. Chen, Y.-H.; Hwang, W.-S.; Ko, C.-H. Sloshing behaviours of rectangular and cylindrical liquid tanks subjected to harmonic and seismic excitations. Earthq. Eng. Struct. Dyn. 2007, 36, 1701–1717. [CrossRef] 24. Xue, M.; Chen, Y.; Yuan, X.; Dou, P. A Study on Effects of the Baffles in Reducing Sloshing in a Container under Earthquake Excitation. In Proceedings of the Twenty-ninth (2019) International Ocean and Polar Engineering Conference, Hawaii, HI, USA, 16–21 June 2019; pp. 3393–3397. 25. Faltinsen, O.M.; Timokha, A.N. Asymptotic modal approximation of nonlinear resonant sloshing in a rectangular tank with small fluid depth. J. Fluid Mech. 2002, 470, 319–357. [CrossRef] 26. Ockendon, H.; Ockendon, J.R.; Johnson, A.D. Resonant sloshing in shallow water. J. Fluid Mech. 1986, 167, 465–479. [CrossRef] 27. Bouscasse, B.; Antuono, M.; Colagrossi, A.; Lugni, C. Numerical and experimental investigation of nonlinear shallow water sloshing. Int. J. Nonlinear Sci. Numer. Simul. 2013, 14, 123–138. [CrossRef] 28. Waterhouse, D.D. Resonant Sloshing Near a Critical Depth. J. Fluid Mech. 1994, 281, 313–318. [CrossRef] 29. Rognebakke, O.F.; Faltinsen, O.M. Sloshing induced impact with air cavity in rectangular tank with a high filling ratio. In Proceedings of the 20th International Workshop on Water Waves and Floating Bodies, Spitsbergen, Norway, 29 May–1 June 2005. 30. Jasak, H.; Jemcov, A.; Tukovic, Z. OpenFOAM: A C++ library for complex physics simulations. In Proceedings of the International Workshop on Coupled Methods in Numerical Dynamics, Dubrovnik, Croatia, 19–21 September 2007; pp. 1–20. 31. Liu, D.; Tang, W.; Wang, J.; Xue, H.; Wang, K. Comparison of laminar model, RANS, LES and VLES for simulation of liquid sloshing. Appl. Ocean Res. 2016, 59, 638–649. [CrossRef] 32. Faltinsen, O.M. A numerical nonlinear method of sloshing in tanks with two-dimensional flow. J. Ship Res. 1978, 22, 193–202. 33. Faltinsen, O.M.; Firoozkoohi, R.; Timokha, A.N. Steady-state liquid sloshing in a rectangular tank with a slat-type screen in the middle: Quasilinear modal analysis and experiments. Phys. Fluids 2011, 23. [CrossRef] 34. Haroun, M.A. Vibration studies and tests of liquid storage tanks. Earthq. Eng. Struct. Dyn. 1983, 11, 179–206. [CrossRef]
You can also read