Fluid–Structure Interaction Modeling of Elastohydrodynamically Lubricated Line Contacts

A CFD-FEM based partitioned fluid structure interaction model to investigate surface cracks in elastohydrodynamic lubricated line contacts

Investigation on the delayed closure of the suction valve in the refrigerator compressor by FSI modeling

3D MRI-based multicomponent thin layer structure only plaque models for atherosclerotic plaques

According to ANSYS - developer of the Multiphysics platform for computer simulations - the FSI (Fluid-Structure Interaction) model can be used in all cases where a fluid encounters a solid structure, for example, wind gusts rotating a turbine, air washing the surface of a moving car etc. This method finds applications especially in the aeronautical and automotive industries, but also in medical research, such computer simulations track the influences of blood pressure and blood flow velocity in the veins. This paper deals with an extension of applying this method in a lesser field, namely in investigating gas explosion events through computer simulations. For this, in the virtual domain, a geometry similar to a house was built, in which an explosive atmosphere generated by an accidental natural gas leak was simulated. Following the source of initiation, the process of rapid combustion of combustible gas takes place, the dynamic effects produced by the pressures generated by the expansion of the gases being calculated and quantified by the FSI model. The results obtained by applying this method in the simulations help in the decision-making process to adopt the most effective measures to prevent explosion-type events of air-fuel mixtures, being useful in the development of explosion risk assessment studies, for identifying the worst-case scenario.

Intervention treatments for aortic stenosis strongly rely on the use of a medical balloon catheter which is utilized for dilating the narrowed aortic valve or the deployment of the implanted devices. However, the complete inflation of the balloon will block the blood outflow and cause instability. This paper demonstrates a computational analysis method to examine the influence of the amount of balloon inflation volume on balloon movement within a pulsating fluid environment. A tri-folded typical shape of the balloon model was inflated by pressurization. The balloon’s front projection area changes during both simulation and experiment were recorded. To address the interaction between the balloon model with varying inflation levels and the introduction of fluid into the arched aorta, a Fluid-Structure Interaction (FSI) model was developed. Compared with the experimental data, the front projection area in the simulation showed a similar increment, which can be used to validate the balloon model. For FSI simulation, the balloon catheter’s maximum displacement rises with the inflation level, with a slight rise at about 10 ml and a substantial rise at 20 ml volume. This work showed a significant advancement in the ability to replicate balloon movement during valvuloplasty using an FSI model.

FSI-simulation of ductile fracture propagation and arrest in pipelines: Comparison with existing data of full-scale burst tests

To build a fluid-structure interaction model of pulmonary veins with total anomalous pulmonary venous connection, which can be used to predict the result of surgical treatment and at the same time to estimate the elastic properties of pulmonary veins based on patient-specific data and clinic postoperative results. The fluid-structure interaction (FSI) model was used to simulate the anastomosis on pulmonary veins based on computed tomography angiography data collected from three children with total anomalous pulmonary venous connection (TAPVC), supra-cardiac type. The deformation and the stress of anastomosis, and also the velocity of blood flow were calculated in fluid-structure coupling algorithm. During the simulation the variable boundary conditions were applied, including the thickness of vessel wall and the vessel elasticity for which was selected a range of values. The calculation results were finally compared to postoperative results of same patients and discussed. The corresponding outcomes are given in the conclusions section. The blood flow velocity through the outlet will vary depending on the properties of vessels, including physical properties and thickness of vessel wall. The stress on vessel is lower for smaller values of Young's modulus. The calculated blood flow velocity correlates well with the postoperative results for the Young's modulus of vessels ranging from 0.5 to 1.0 MPa. The FSI model has high potential to predict the result of surgery for TAPVC and to estimate the physical properties of pulmonary vein. This model also has potential to guide the strategy for surgical treatment.

Investigation of the effect of adaptive characteristics on non-cavitating noise for flexible propeller in non-uniform flow via the fluid-structure interaction model

It is a consensus that salt heaving and frost heaving are typical distresses in the sulfate saline soil subgrade. To further investigate the mechanic response of pavement structure in sulfate saline soil area, a finite element(FE) model was established based on fluid-structure interaction(FSI) model in this paper. Then the mechanic response of the asphalt pavement under traffic loads, salt heaving and frost heaving was simulated and analyzed. It is shown that only under salt heaving and frost heaving, the tensile strength of asphalt surface course was seriously inadequate and that at the bottom of semi-rigid base course were negative, which may be helpful to crack resistance at the bottom of base courses. Besides, traffic loads could help to dramatically counteract displacement, tensile stress and strain. However, as a whole, in sulfate saline soil area, asphalt courses should strengthen crack resistance and foundation treatment.

Performance-based seismic evaluation is usually done by considering simplified models for the liquid storage tanks therefore, it is important to validate those simplified models before conducting such evaluation. The purpose of this study is to compare the seismic response results of the FSI (fluid-structure interaction) model and the simplified models for the cylindrical liquid storage tanks and to verify the applicability of the simplified models for estimating failure probability. Seismic analyses were carried out for two types of storage tanks with different aspect ratios (H/D) of 0.45 and 0.86. FSI model represents detailed 3D fluid-structure interaction model and simplified models are modeled as cantilever mass-spring model, frame type mass-spring model and shell type mass-spring model, considering impulsive and convective components. Seismic analyses were performed with modal analysis followed by time history analysis. Analysis results from all the models were verified by comparing with the results calculated by the code and literature. The results from simplified models show good agreement with the ones from detailed FSI model and calculated results from code and literature, confirming that all three types of simplified models are very valid for conducting failure probability analysis of the cylindrical liquid storage tanks.

We propose a Navier--Stokes--Biot fluid-structure interaction (FSI) model to study the interaction between an incompressible, viscous Newtonian fluid and a poroelastic medium with permeability depending on the volumetric change of pore size. The FSI model is coupled to a set of advection-reaction-diffusion equations defined on moving domains so that we may study the interaction between the blood flow, a stented coronary artery, and time-dependent pharmacokinetics of drug absorption in drug-eluting stents. A monolithic approach is used to implement the proposed problem numerically within the context of finite element discretization. Nitsche's method is employed to enforce one of the coupling conditions at the moving fluid-poroelastic structure interface. Stability analysis is presented, providing conditions on Nitsche's penalty parameter under which the scheme is unconditionally stable. Using 3D simulations, five geometrically different metallic stent platforms are considered with two different pharmacokinetics to show how stent geometry and type of coating impact the biomechanical environment, the local hemodynamics, and the concentration of the pharmacological agents within the vascular wall and artery lumen. It is found that stent implantation changes the permeability properties of the arterial wall, as well as local hemodynamics, which may be responsible for the so-called edge effect, i.e., suboptimal reduction in restenosis rates near the edges of drug-eluting stents. To the best of our knowledge, this is the first study of drug-eluting stents that takes into account fluid-poroelastic structure interaction with permeability depending on the volumetric change of the pore size, coupled to an advection-reaction-diffusion model defined on moving domains.

The high performance of nature’s creations and biological assemblies has inspired the development of engineered counter parts that may outperform or provide new capabilities to conventional systems. In particular, the wings of bats contain distributed arrays of micro-scaled flow sensitive hair receptors over their surface, which inspires artificial hair sensors (AHS) development in aerodynamic feedback control designs using the micro-electro-mechanical systems (MEMS). One approach investigates the possibility of installing AHS on the leading edges of the wings of small-scaled unmanned aerial vehicles (UAVs) to improve the aerodynamic control. Our major motivation for the present study is that current mathematical models have limited relevance to aerodynamic situations because they are analyzed in steady or purely oscillatory flows. Our overall objective is to understand AHS fluid-structure interaction (FSI) in flow regimes relevant to small-scaled UAVs, for which we speculate a steady baseline flow perturbed by an oscillatory component is an appropriate flow reference condition. Towards understanding the AHS in this situation, we investigate the dynamic response of a hair receptor in a creeping flow environment with a steady and oscillatory component. We present time varying deflection and bending moment of the artificial hair sensors at different freestream velocities. For this, a three-dimensional FSI model is developed for the flexible hair-structure in the airflow, which is coupled with a finite element model using the computational fluid dynamics (CFD). The Navier-Stokes equations including continuity equation are solved numerically for the CFD model. To describe the dynamic response of the hair receptors, the natural frequencies and mode shapes of the hair receptors, computed from the FSI model, are compared with the excitation frequencies of the surrounding airflow. This model also describes both the boundary layer effects and effects of inertial forces due to FSI of the hair receptors. For supporting the FSI model, the dynamic response of the hair receptor is also validated considering the Euler-Bernoulli beam theory including the steady and unsteady airflow.

In this study a one-way coupled fluid-structure interaction (FSI) between ocean waves and a simplified offshore platform deck structure was modeled. The FSI model consists of a Volume of Fluid (VOF) based hydrodynamics model, a structural model and an interface to synchronize data between these two. A Computational Fluid Dynamics (CFD) analysis was used to capture the breaking wave and impact behavior of the fluid on the structure using commercially available software STAR-CCM+. A 3D Finite Element (FE) model of the platform deck developed in ABAQUS was used to determine the deflection of the structure due to hydrodynamic loads. Nonlinear material behavior was used for all structural parts in the FE model. Transient dynamic structural analysis and CFD analysis were coupled by transferring the CFD-predicted pressure distribution to the structural part in each time step using the co-simulation capabilities of STAR-CCM+ and ABAQUS. The one-way FSI model was applied to investigate the possible physical causes of observed wave damage of an offshore platform deck during a hurricane. It was demonstrated that with proper physical conditions/configurations, the FSI model could reproduce a structural deformation comparable to field measurement and provide valuable insight for forensic analysis.

Understanding the dynamic response of naval structures subjected to underwater explosions (UNDEX) is crucial for offshore and marine engineering applications. This study presents a novel fluid-structure interaction (FSI) modelling strategy to simulate the vibro-acoustic response of hull structures impacted by far-field UNDEX, balancing computational efficiency and accuracy. A hybrid 1-D/3-D numerical approach is proposed to simulate far-field pressure wave propagation and near-field effects, FSI and structural response. MSC Dytran is employed for UNDEX simulation and FSI, while Actran VI is used for the subsequent vibro-acoustic analysis. The method enables the assessment of structural deformation, induced vibrations, and structure-borne noise in a representative ship section. The findings highlight the importance of integrating vibro-acoustic evaluations into UNDEX analyses and demonstrate the advantages and limitations of the proposed approach in terms of computational cost and accuracy, discussing future improvements to enhance efficiency and applicability in industrial and research contexts. HIGHLIGHTS A combined 1-D – 3-D model is developed to study far-field UNDEX with reduced computational costs. Structural dynamic analysis is coupled with vibro-acoustic simulation to study UNDEX effect. Structural deformation, Von Mises stress, induced vibrations, and radiated noise are evaluated. Vibration and noise levels are useful for the design of equipment and safety devices for the crew on board. The proposed numerical modelling is reliable and useful in the preliminary engineering design of marine vessels.

A coupled high-accuracy phase-field fluid–structure interaction framework for Stokes fluid-filled fracture surrounded by an elastic medium