One-way Fluid-structure Interaction Research Articles

Assessment of typhoon-induced wind and wave effects on fatigue crack growth life in offshore wind turbines

ABSTRACT Fatigue and structural failures in OWT towers are common due to sustained aerodynamic and wave loads. This study predicts the remaining service life of 2.1MW jacket-type Offshore Wind Turbine (OWT) towers, focusing on fatigue crack growth life (FCGL). Using one-way fluid-structure interaction (FSI) simulations with Typhoon "Muifa" parameters, it analyzes stress under wind, wave, and current effects. FNK theory and linear elastic fracture mechanics are applied to calculate FCGL under various loads. The results indicate that the participation of waves and currents significantly affects the stress distribution in both the tower and the tower frame. During the crack propagation process, cracks initially propagate along the thickness direction and then extend along a straight path after penetrating the thickness. Under typhoon conditions, waves and currents cause a significant reduction in the FCGL of the tower, decreasing from 2.46 years to 1.48 years numerically.

One-way fluid–structure interaction modeling and multi-objective optimization of horizontal-axis wind turbine blades equipped with winglets

ABSTRACT This study aims to investigate the effects of backward-directed winglets applied on the NREL Phase-II reference wind turbine geometry on structural and aerodynamic characteristics and to reveal optimized configurations. The aerodynamic pressure distributions on the blades were imposed as boundary conditions for the FEM analyses since the structural characteristics of the turbine were analyzed by adopting a one-way Fluid Structure Interaction (FSI) approach. The Taguchi analysis with an L27 orthogonal array revealed the descending order of importance of design variables on the coefficient of power ( C P ): height, cant angle, toe angle, curvature radius, and finally twist angle. For von-Mises stress, the descending order of importance is height, cant angle, toe angle, twist angle, and curvature radius. A multi-objective genetic algorithm using artificial neural network (ANN) models was used to optimize the objectives C P and von-Mises stress. Pareto-optimal solutions with off-design points were obtained, and their performances were compared to the reference NREL Phase-II geometry. As a result, it was observed that there was an increase in C P from 8.07% to 15.56% and the von-Mises stress showed a considerable increase up to 231.13%. The study demonstrates the aerodynamic benefits and structural drawbacks of various winglet designs in horizontal axis wind turbines.

Numerical Analysis on Static Performances of Graphene Platelet-Reinforced Ethylene-Tetrafluoroethylene (ETFE) Composite Membrane Under Wind Loading

This study examines the static performances of a graphene platelet (GPL)-reinforced ethylene tetrafluoroethylene (ETFE) composite membrane under wind loadings. The wind pressure distribution on a periodic tensile membrane unit was analyzed by using CFD simulations, which considered various wind velocities and directions. A one-way fluid–structure interaction (FSI) analysis incorporating geometric nonlinearity was performed in ANSYS to evaluate the static performances of the composite membrane. The novelty of this research lies in the integration of graphene platelets (GPLs) into ETFE membranes to enhance their static performance under wind loading and the combination of micromechanical modelling for obtaining material properties of the composites and finite element simulation for examining structural behaviors, which is not commonly explored in the existing literature. The elastic properties required for the structural analysis were determined using effective medium theory (EMT), while Poisson’s ratio and mass density were evaluated using rule of mixtures. Parametric studies were carried out to explore the effects of a number of influencing factors, including pre-strain, attributes of wind, and GPL reinforcement. It is demonstrated that higher initial strain effectively reduced deformation under wind loads at the cost of increased stress level. The deformation and stress significantly increased with the increase in wind velocity. The deflection and stress level vary with the wind direction, and the maximum values were observed when the wind comes at 15° and 45°, respectively. Introducing GPLs with a larger surface area into membrane material has proven to be an effective way to control membrane deformation, though it also results in a higher stress level, indicating a trade-off between deformation management and stress management.

Numerical investigation on the effect of an orifice plate on the flow-induced and acoustically induced vibration of a gas transmission pipe

In this paper, a numerical method is proposed for investigating the flow-induced vibration (FIV) and acoustically induced vibration (AIV) of a straight pipe with an orifice plate. First, the turbulent pressure (TP) and acoustic pressure (AP) signals on the pipe wall were obtained through the simulation of an unsteady flow field and the application of Mohring's analogy, respectively. Subsequently, the FIV and AIV of the pipe were calculated by means of one-way fluid-structure interaction and acoustic-structure interaction, respectively. The calculated pressures, flow velocities, and sound powers at the monitoring point were in good agreement with the experimental results reported in the literature. The numerical results revealed that the power spectral densities of the AP were significantly higher than those of the TP on the surface of the tested end pipe, particularly at the natural frequencies of the acoustic modes. In the low-frequency regime, FIV was the dominant factor, whereas in the medium-high frequency regime, particularly above the cutoff frequency of the plane wave, AIV was the dominant factor. The findings of the parametric studies demonstrated that the AP and AIV of the pipe exhibited a considerable increase with the Mach number. Conversely, the TP and FIV demonstrated a more pronounced rise when the Mach number increased from 0.1 to 0.2, followed by a less pronounced increase when the Mach number increased from 0.2 to 0.3. A reduction in the orifice diameter resulted in an increase in the AP and AIV. In contrast, the TP and FIV exhibited a comparatively minor increase.

Studying and analysis of deformation and stresses in horizontal-axis wind turbine using fluid-structure interaction method

Fluid-structure interaction (FSI) studies have become an important tool in the development of wind turbine blades as well as for analyzing and optimizing Horizontal Axis Wind Turbine (HAWT). The most essential elements for estimating the turbine blade strength to withstand extreme wind loads and aerodynamic performance are the blade deformation and the associated stresses. This study aims to compare the strength and analyze the deformation behavior of two models of HAWT blades. A three-dimensional model was created and loaded into a Finite Element (FE) model for analysis. The Computational Fluid Dynamics (CFD) investigation was coupled with the structural model using one-way FSI. In this article, the effect of the aerodynamics on the blade surface of a small HAWT has been studied numerically and experimentally. The airfoil used for the blade profile is S826 airfoil. To provide an appropriate displacement for static measurements, the blade in the experimental investigation is made of thermoplastic polyurethane material (TPU). It is noted that the current experimental findings verify the simulation results, and a comparison between the simulations and the experimental findings reveals a reasonable agreement. The numerical simulations are also implemented on a HAWT epoxy E-glass unidirectional (EEGUD) material. It can be concluded from this study that the blade deformation and stress on the blades are related to the wind speed. The deformation along the span length exhibits nonlinear variation that gradually increases from the blade root and reaches its maximum at the blade tip position. The tip deflection and equivalent stress were found to increase with an increase in wind speed. The dynamic analysis at different tip speed ratios shows the highest deformation at λ = 4, for wind speed of 20 m/s.

Structural Optimization of a Large-Scale 3D-Printed High-Altitude Propeller Blade with Experimental Validation

This paper presents a structural optimization of a 3D-printed thermoplastic-core propeller blade for high-altitude unmanned aerial vehicles using a genetic algorithm. It aims to minimize the weight of the blade by creating longitudinal holes and spars and to minimize the blade tip deflection during operation at an altitude of 16 km. The objective is to check the validity of a 3D-printed material modeling approach for large-scale and more complex 3D-printed parts, such as hollow twisted blades. The approach is based on attentively selecting the printing parameters that reduce the anisotropy of the 3D-printed parts. The linear isotropic behavior of 3D-printed Polylactic Acid and Acrylonitrile Butadiene Styrene M30 tensile samples, which have been tested at ambient and low temperatures (−60°C), is utilized to numerically predict the experimental deformation and natural frequencies of 3D-printed substitute and twisted full blades with good accuracy. The validated linear isotropic model of each material is then used to evaluate the objectives and the constraints of the two-objective optimization process using one-way fluid–structure interaction. Four optimized blades have been selected from the Pareto fronts as candidates, printed, and tested in bending and vibration. The numerical and experimental results of the candidate blades in terms of deformation and natural frequencies are in good agreement, proving the validity of the present macroscale approach for large-scale hollow twisted blades.

Aerodynamic Analysis of Blade Stall Flutter Prediction for Transonic Compressor Using Energy Method

In this study, stall flutter onset prediction in a transonic compressor is carried out using the (uncoupled) energy method with Fourier transform. As the study is conducted computationally using computational fluid dynamics (CFD)-based simulations, the energy method was employed due to its higher computational efficiency by implementing the one-way FSI (Fluid Structure Interaction) model. The energy method is relatively uncommon for determining the aerodynamic damping and flutter prediction, specifically in blade stall conditions for the 3D blade passages. The NASA Rotor 67 was chosen for the validation of the study due to the availability of a wide range of experimental data. A flutter prediction analysis was performed computationally using CFD for the two-blade passages of the rotor in the peak efficiency and stall regions. Prior to this, the modal analysis on the prestressed blade was conducted, considering the centrifugal effects. The modal analysis provided accurate blade frequency and amplitude, which were the inputs of the flutter analysis. The first three modes of blade resonance were studied with a range of nodal diameters within near-peak efficiency and stall regions. The energy method implemented in this study for the flutter analysis was successfully able to predict the aerodynamic damping coefficients of the first three modes for a range of nodal diameters from the periodic-unsteady solution of the defined blade oscillation within the regions of interest (peak efficiency and stall point). The results of the study confirm the rotor blade’s stability within the near-peak region and, most importantly, the prediction of the flutter onset in the stall region. The study concluded that the computationally inexpensive and time-efficient energy method is capable of predicting the stall flutter onset. In the future, further validations of the energy method and investigations related to flow mechanism of stall flutter onset are planned.

Comparison of Laminar and Turbulent K–Omega Shear Stress Transport Models Under Realistic Boundary Conditions Using Clinical Data for Arterial Stenosis

Abstract Early diagnosis of cardiovascular diseases (CVDs), including arterial stenosis, enables targeted treatments that reduce CVD mortality. It is vital to improve the accuracy of early diagnostic tools. Current computational studies of stenosis use mathematical models, such as laminar and k–omega shear stress transport (SST) models, available in ansys (Fluent and CFX), openfoam, and comsol software packages. Users can adjust boundary conditions, such as inlet velocity and outlet pressure using user-defined functions (UDFs) with different expressions and constant values. However, currently there is no rule over what to impose at these boundaries, and previous studies have used various assumptions, such as rigid artery wall, one-way fluid–structure interaction (FSI) or two-way FSI, and the blood's Newtonian or non-Newtonian material properties. This variety in construction has associated deviations of the models from the clinical data and lessens the value of the models as potential diagnostic or predictive tools for medical practitioners. In this study, we examine arterial stenosis models, with severities of 20%, 40%, and 50%, compared with the healthy artery analyzed in terms of strain energy to the artery wall. Additionally, we investigate elastic walls using one-way FSI, comparing with laminar and k–omega SST. These boundary conditions are based on clinical data. The results regarding the strain energy (mJ) behavior along the artery wall show that the k–omega SST model outperforms the laminar model for short arterial segments and under the Newtonian assumption with a no-slip boundary wall and turbulent flow.

Design and dynamic analysis of a spanwise morphing wing for Mars exploration

The application of spanwise morphing wings makes it possible to transport and launch large-size Mars exploration UAVs. This article proposes a modular variable spanwise morphing wing for high-aspect-ratio aircrafts, and analyses the characteristics of the morphing wing by theoretical analysis, numerical simulation and experimental verification. The novel spanwise morphing wing is based on the Sarrus-inspired deployable structure, which can increase the wing's lift by changing the spanwise length. The pre-strain torsion springs are assembled to provide the initial driving moment of the morphing mechanism. A regular triangle cross section is selected by evaluating the bending and torsional stiffness, and deployable triangular prism mechanisms are identified. Through releasing the pre-strain torsion springs to achieve expansion and implant Sarrus linkages along the straight motion paths. A lockable structure is designed, and the main factors affecting the self-locking property are analysed. A rigid origami skin is proposed, which maintains the airfoil's continuous smoothness after spanwise morphing. The kinematics of the spanwise morphing wing unit is developed using the Lagrange equation, and the theoretical models of morphing wings with different numbers of units are obtained. The unit numbers influence fully expanded time, and the time decreases gradually along the wingtip's direction. Finally, a one-way fluid-structure interaction analysis is performed to investigate the spanwise morphing mechanism and origami skin response under aerodynamic loads. Results show that the skeleton mechanism's maximum stress is below the material's yield strength, and the origami skin's maximum out-of-plane deformation is less than 0.5% of the wing chord, which provides a necessary theoretical basis for applying the spanwise morphing wing.

Fluid–structure interaction of a marine rudder at incidence in the wake of a propeller

The structural response of a rudder in the wake of a marine propeller is investigated by one-way fluid–structure interaction approach. The unsteady pressure field gathered by detached eddy simulations is provided to a structural solver for the computation of deformations and stresses of the rudder. The study compares the structural response of the rudder at neutral and two equal and opposite rotations, which are representative of design conditions in straight motion and maneuvering conditions that are experienced under the action of the autopilot for course control or weak maneuvering. The analysis sheds light on the different structural behavior at the two opposite rotation angles, caused by asymmetrical variation along the span of the rudder of the angle of attack induced by the propeller slipstream, by considering the different role played by the tip and hub vortical systems. The test case consists of a rudder with a rectangular plane area and National Advisory Committee for Aeronautics 0015 sectional profile located past the E779A propeller. The propeller operates at low loading conditions, and the rudder is set at incidence δ=0∘,±4∘. The study shows that the response of the rudder is driven by flap and torsion and is asymmetric for the two and opposite rotations. The mean deformation and vibratory response are magnified for δ=−4∘ by at least 70% and 20% for the lateral and edgewise deflections, respectively, with respect to the opposite rudder incidence. In general, the excitation generated by the tip vortex is stronger than that of the hub vortex. In the most critical condition, at δ=−4∘, the excitation associated with the tip vortex is nearly double that of the hub vortex.

One-Way Fluid–Structure Interaction Simulation of the Added Damping of T(0,1) Modes of Two Partially Overlapped Identical Plates in Still Water

Abstract Structures with a partially overlapped status in water can be seen in some engineering applications, and the fluid-structure coupling vibration behavior of two partially overlapped identical plates has been studied previously through the experimental method. In this study, the added damping of the T(0,1) modes of two submerged partially overlapped plates is numerically investigated through the one-way fluid-structure interaction (FSI) method. The relevant numerical settings, like the mesh size, calculated periods, time-step size, and vibration amplitude, were tested first. Then, the numerical results were compared with experimental results, and good agreements were found. Finally, numerical results were analyzed. The vibration status of two plates in the joint abutting area or the overlapped area has an important influence on the added mass variation. When the added mass is higher, the phase difference between modal force and vibration displacement is also greater, which is the main reason for the higher added damping. The relationship between the phase difference and the frequency in water can be approximately fitted to a straight line, which can probably be used to predict the added damping variations caused by fluid boundary changes of submerged structures.

NGHIÊN CỨU TRƯỜNG ỨNG SUẤT BÁNH CÔNG TÁC TẦNG ĐẦU TIÊN MÁY NÉN ĐỘNG CƠ TUA BIN KHÍ TV3-117 BẰNG MÔ PHỎNG SỐ

This article presents the results of stress field calculations for the first stage compressor impeller using the one-way fluid-structure interaction (FSI) method, which helps determine stress concentration zones and safety factors. Numerical analysis conducted with Ansys software reveals that stress concentration occurs near the blade root on the suction side and within the blade lock-disc zone. In these stress concentration zones, such as the blade lock-disc zone and blade suction side, the minimum safety factor is found to be above 2.27. These findings serve as a foundation for future research on impeller stress fields using two-way FSI methods and for providing recommendations to optimize the stress concentration field in the compressor disc.

Study on the optimal elastic modulus of flexible blades for right heart assist device supporting patients with single-ventricle physiologies.

Patients with single-ventricle physiologies continue to experience insufficient circulatory power after undergoing palliative surgeries. This paper proposed a right heart assist device equipped with flexible blades to provide circulatory assistance for these patients. The optimal elastic modulus of the flexible blades was investigated through numerical simulation. A one-way fluid-structure interaction (FSI) simulation was employed to study the deformation of flexible blades during rotation and its impact on device performance. The process began with a computational fluid dynamics (CFD) simulation to calculate the blood pressure rise and the pressure on the blades' surface. Subsequently, these pressure data were exported for finite element analysis (FEA) to compute the deformation of the blades. The fluid domain was then recreated based on the deformed blades' shape. Iterative CFD and FEA simulations were performed until both the blood pressure rise and the blades' shape stabilized. The blood pressure rise, hemolysis risk, and thrombosis risk corresponding to blades with different elastic moduli were exhaustively evaluated to determine the optimal elastic modulus. Except for the case at 8,000 rpm with a blade elastic modulus of 40 MPa, the pressure rise associated with flexible blades within the studied range (rotational speeds of 4,000 rpm and 8,000 rpm, elastic modulus between 10 MPa and 200 MPa) was lower than that of rigid blades. It was observed that the pressure rise corresponding to flexible blades increased as the elastic modulus increased. Additionally, no significant difference was found in the hemolysis risk and thrombus risk between flexible blades of various elastic moduli and rigid blades. Except for one specific case, deformation of the flexible blades within the studied range led to a decrease in the impeller's functionality. Notably, rotational speed had a more significant impact on hemolysis risk and thrombus risk compared to blade deformation. After a comprehensive analysis of blade compressibility, blood pressure rise, hemolysis risk, and thrombus risk, the optimal elastic modulus for the flexible blades was determined to be between 40 MPa and 50 MPa.

Effect of RVAD Cannulation Length on Right Ventricular Thrombosis Risk: An In Silico Investigation

Left ventricular assist devices (LVADs) have been used off-label as long-term support of the right heart due to the lack of a clinically approved durable right VAD (RVAD). Whilst various techniques to reduce RVAD inflow cannula protrusion have been described, the implication of the protrusion length on right heart blood flow and subsequent risk of thrombosis remains poorly understood. This study investigates the influence of RVAD diaphragmatic cannulation length on right ventricular thrombosis risk using a patient-specific right ventricle in silico model validated with particle image velocimetry. Four cannulation lengths (5, 10, 15 and 25 mm) were evaluated in a one-way fluid–structure interaction simulation with boundary conditions generated from a lumped parameter model, simulating a biventricular supported condition. Simulation results demonstrated that the 25-mm cannulation length exhibited a lower thrombosis risk compared to 5-, 10- and 15-mm cannulation lengths due to improved flow energy distribution (25.2%, 24.4% and 17.8% increased), reduced stagnation volume (72%, 68% and 49% reduction), better washout rate (13.0%, 11.6% and 9.1% faster) and lower blood residence time (6% reduction). In the simulated scenario, our findings suggest that a longer RVAD diaphragmatic cannulation length may be beneficial in lowering thrombosis risk; however, further clinical studies are warranted.

Numerical analysis of inflow turbulence intensity impact on the stress and fatigue life of vertical axis hydrokinetic turbine

The present study aims to analyze the effect of upstream turbulence intensity on the hydrodynamic and structural performance of the straight-blade vertical axis turbine. To achieve this, a one-way fluid structure interaction analysis is conducted within the ANSYS workbench environment. Initially, computational fluid dynamics (CFD) simulation is performed at different values of upstream velocity values. Additionally, the impact of upstream turbulence intensity is also analyzed. The CFD simulation results were validated against published experimental work. Once CFD simulation is performed then computed fluid loads are transferred to the ANSYS mechanical structural module. Finite element modeling is performed to compute the stresses and the fatigue life. The study reveals that increasing the upstream turbulence intensity from 5% to 20% leads to 8.6% improvement in the turbine's power performance. However, turbulence intensity also results in 35.6% increase in Von-Mises stresses produced within the designed turbine. However, even with this increase, the Von-Mises stresses remain below a critical threshold, measuring at 173.34 MPa when the upstream water velocity is 1.4 m/s, and the inflow turbulence intensity is at 20%. This stress level is well within the material's yield strength, ensuring the turbine's structural integrity. Moreover, the simulation results emphasize that turbulence intensity has a significant impact on the turbine's fatigue life. Further, it is predicted that an increase in turbulence intensity from 5% to 20% leads to a significant 40% reduction in the turbine's fatigue life. The stress analysis results reveal that struts, strut–blade joints, and strut–shaft joints are the key stress concentration areas. The results suggested that an increase in upstream turbulence intensity has favorable impact on turbine performance, however, for highly turbulent flows turbine should have higher strength and key areas should be focused on designing turbine for such flow conditions.

Farklı Isı ve Basınç Koşulları Altında Düz Bir Boru İçin Tek Yönlü Akışkan-Yapı Etkileşimleri Analizi

Numerical studies on stress, deformation, and damages due to fluid flow have been highly carried out using Fluid-Structure Interaction (FSI) in recent years. FSI is highly efficient in investigating a solid domain deformed by the fluid flow. In this study, a one-way fluid-structure interaction study is performed by a straight pipe under different pressure and thermal conditions. Here, the thermophysical properties of the fluid and mechanical properties of the solid domain can be subjected to change during fluid flow. An aluminum straight pipe with a 1 mm wall thickness is operated under 1 Bar, 5 Bar, and 10 Bar with three different surface temperatures -10ºC, 20ºC, and 50ºC. This study aims to investigate the structural variation of aluminum by the temperature and pressure change of operating fluid in the pipe. Variation of thermophysical properties of fluid by heated pipe surface is integrated into the numerical analysis by generated functions. Numerical analysis showed that the variation of temperature in operating fluid highly affects the fluid characteristic and the structural response of the solid domain by different temperatures. An increase in the operating pressure caused maximum deformation to approximately %100 from 1 Bar to 5 Bar, and approximately %120 from 1 Bar to 10 Bar for the adiabatic process as expected but in the heating conditions stress is nearly three times higher than cooling conditions. As a result, one-way FSI solutions are highly effective in investigating the deformed solid domain as a result of flow, thermal, and operating conditions.

Influence of deformed parent vessel on rupture risk of micro cerebral aneurysm: Numerical study

One of significant impact of stent usage for the treatment of the saccular aneurysm is deformation of the parent vessel. Present study demonstrates the influence of the aneurysm deformation caused by the stent on the risk of aneurysm rupture. Computational fluid dynamic is applied for the modeling of the blood flow inside three internal carotid artery (ICA) aneurysms with different neck angles. One-way fluid–structure interaction model is applied for the interaction of the blood and vessel. Two stage of deformation is applied on the parent vessel to analyze the influence of deformation on the hemodynamic factors of wall shear stress and oscillatory shear index. Achieved results indicate that the deformation of the aneurysm by the stent significantly reduce wall shear stress is on the sac wall and decrease the risk of internal carotid artery ICA aneurysm rupture. Our finding confirm that the main effect of aneurysm deformation is reduction of the blood velocity near ostium region.

One-way fluid structure interaction analysis of a static savonius hydrokinetic turbine under different velocity and surface roughness with different blade materials

Hydrokinetic turbines are prone to a harsh hydrodynamic environment with intricate vortical flows that elevate the probability of failure. The degradation of the blade surface caused by corrosion can impact the blade's hydrodynamic and the structural performance. This paper reports a one-way three-dimensional fluid-structure interaction simulation to analyse the performance of a static Savonius hydrokinetic turbine at varying rotor positions, with different surface roughness and water velocities, in terms of coefficients of static torque, static torque, stresses, and blade deformation. The simulations revealed that the optimum position for the highest coefficient of static torque was at 15° (Cst = 0.30) in reference to the water flow. Increasing the water velocity from 0.4 ms−1 to 0.84 ms−1 improved the turbine static torque due to an increase in the kinetic energy. However, the presence of surface roughness has deterioration effects on the static torque coefficient due to a delayed separation which causes a drag reduction. The simulation predicted no structural failure at 0.4 ms−1 and 0.84 ms−1, but varying materials exhibited varying maximum principal stress and deformation, highlighting the significance of the early development of materials selection process. The maximum von Mises stress and deformation was obtained when the turbine is resting at 45° for aluminium blade (σ = 1.05 MPa, ε = 5.6e−4 mm). The results of this study indicate suitable materials from a hydrodynamic and material perspectives for the construction of the Savonius hydrokinetic turbine, which can be implemented in the design process to potentially save cost and minimize turbine downtime.

One-Way Fluid Structure Interaction of a Utility Vehicle Splitter using CFD Modelling

The Utility Vehicle, commonly known as a “ute” in New Zealand, and a “pickup” in other countries, is very popular for work, recreation and motorsport. This report investigates how the addition of a front splitter influences the handling ability on a Ford Courier Ute, for better aerodynamics during racing. Computational fluid dynamics (CFD) methods and Finite Element Analysis (FEA) were used to investigate the one-way fluid structure interaction of the speed of the Ute with and without the splitter modification. Three configurations of the splitter were modelled and analysed using SolidWorks 2022, CFD and FEA packages. The ground clearance between the splitter and the road was set at three heights, 200 mm, 150 mm and 50 mm. These designs were compared with the control, in terms of the amount of downforce, drag and aerodynamic efficiency. The ground clearance of 150 mm was optimal, in terms of the parameters investigated. The findings from this paper may inspire Ute enthusiasts to fit a splitter to their Ute for racing applications.

Development of Numerical Modelling Techniques for a Firefighting Water Tank with an Anti-Wave Plate under Seismic Loads

A structure located in seismic regions must have a resistance capacity based on current seismic design codes and maintain this capacity for its design life. However, the responses of structures to several major earthquakes worldwide over the past decade have demonstrated the inadequacy of current seismic design codes. Thus, there is a need for an accurate method for assessing the strength of structures under seismic loads. Accordingly, this study aimed to numerically review the structural performance of a typical firefighting water tank equipped with an anti-wave plate under seismic loads. Quasi-static and transient structural analysis methods were developed to determine the structural strength of the water tank. In addition, a one-way fluid–structure interaction (FSI) method was developed to analyse the effect of the anti-wave plate on the liquid-sloshing motion in and the structural strength of the water tank. Moreover, convergence tests were performed to aid the development of mesh models and grid models for finite element method and finite volume method analyses, respectively. Subsequently, the structural responses of the water tank were determined via quasi-static, transient, and one-way FSI analyses. Finally, the effectiveness of the anti-wave plate for mitigating the sloshing pressure in the water tank and the structural responses according to the pressure change were analyzed. The commercial software ANSYS Workbench (ver. 2020R2) was used.