Prosthetic heart valves deployed in the left heart (aortic and mitral) are subjected to harsh hemodynamical conditions. Most of the tissue engineered heart valves have been developed for the low-pressure pulmonary position because of the difficulties in fabricating a mechanically strong valve, able to withstand the systemic circulation. This necessitates the use of reinforcing scaffolds, resulting in a tissue-engineered textile reinforced tubular aortic heart valve.
Cardiovascular disease is the leading cause of death in developed Cardiovascular disease is the leading cause of death in developed nations and imposes a high socioeconomic cost. In 2014, Dassault Systemes launched the Living Heart Project to harness the power of realistic simulation to tackle the problem of cardiovascular disease. The cornerstone of the project is the Living Heart Model (LHM), an anatomically and physiologically realistic model of a human heart that can be used for in silico diagnosis and treatment of cardiovascular disease. In this paper, we describe applications of the model in medical device design, drug safety, and patient care.
In this paper, the modeling and simulation of the blood flow in the real patient heart is described. In order to cure the patients with cardio vascular disorder it is important to make appropriate choice of an artificial heart valve, it is important to exactly understand the behavior of the heart blood flow of the specific patient under treatment. The presented approach is based on the Magnetic Resonance Imaging/Tomography, which provides the necessary input to create the heart shape (“its geometry”) and its variation in time (tens or hundreds of frames) to define the internal time-dependent heart volumes for one heartbeat. Once this geometry is defined, the CFD software is applied to simulate the internal blood flow and further on visualize it to enable its further analysis. The applied CFD tool is FlowVision, due to its possibility to fully automatically perform the mesh generation of arbitrary shapes, as the heart geometry requires. In addition, FlowVision applies the dynamic mesh refinement by taking into account the motion of the heart-modeled surface, required by the CFD Euler model. The presented CFD approach to simulate the human internal blood flow is validated with data from MRI/MRT scans of the real heart and the respective simulation test cases are presented.
Cardiovascular disease is the leading cause of death in developed countries and continues to drive significant research aimed at improving diagnosis and treatment. In cases where therapeutic medical device intervention is warranted, it is important to account for device-heart interaction over both the short and long term. In the short term, cardiac motion can significantly impact device stability and performance (as in the case of artificial heart valves), while over the long term, modified blood flow patterns may lead to structural remodeling that can have adverse effects on cardiovascular function. Computational tools used for device design, sizing, and placement must therefore be able to account for cardiac/vascular tissue mechanics, blood flow, and the interaction between them. Moreover, such tools must allow for patient-specific modeling and provide interactive visualization capabilities that can support clinical decision-making and reduce operator error.
Blood flow velocity at different time points in the FSI simulation
In this paper, we describe a methodology for bidirectional fluid-structure interaction between the general purpose CFD code FlowVision and the SIMULIA Living Heart Human Model (LHHM), a dynamic, anatomically realistic, four-chamber heart model that considers the interplay and coupling of electrical and mechanical fields acting in concert to regulate the heart filling, ejection, and overall pump functions. The LHHM natively includes a 1D fluid network model capable of representing dynamic pressure/volume changes in the intra- and extra-cardiac circulation. In the current work, we first replace this network model with a full 3D blood model (solved in FlowVision) that provides detailed spatial and temporal resolution of cardiac hemodynamics driven by motions of the beating heart and constrained with appropriate time-varying boundary conditions derived from the literature. After validating this approach, we activate bidirectional coupling between the blood flow CFD model and the LHHM electromechanical model using the SIMULIA co-simulation engine and discuss modeling details and results of interest.
Hydroplaning is a major cause of wet-road accidents. The main contact element between the ground and vehicle is the tire. Tire safety and performance are therefore critically important. Wet roads present several uncontrollable factors. This paper uses CFD (Computational Fluid Dynamics) to analyze wet road hydroplaning effects. Fluid dynamics cannot be easily measured using normal experiments. Therefore the braking distance and record rolling vary by encoder. We propose another method to analysis it. By this result, the large groove and tire depth can reduce hydroplaning effects. A second method is modifying the tire void pattern which can reduce the hydroplaning extent by 29%.
A deeper understanding of the interaction between machine, packaging material and liquid product during the forming process of pouches is enabled by the use of numerical simulation.
An approach for solving Fluid Structure Interaction in aerospace application is presented in this paper. The proposed approach is based on the two-way coupling between CFD code FlowVision and FEA code ABAQUS. The codes are coupled directly without using any 3rd party software or intermediate
structure.
The proposed fluid-structure interaction (FSI) approach is based on a two-way coupling between finite-element code Abaqus and finite-volume code FlowVision. The FSI simulation is possible due to a unique mesh generation method used in FlowVision.
During operation of vertical cylindrical tanks for storage of oil and oil products significant quantities of compacted sediments can be formed and accumulated. As a result, tank useful capacity, tank farm turnover are reduced, oil storage cost is increased due to the
necessity to put tanks out of operation and perform their cleaning.
The paper presents a numerical simulation of the drop test in a still water for the multi-component box structure. The complexity of the problem is in the strong fluid-structure interaction (FSI) between the box and the water free surface. The numerical simulation of the drop test is performed with two software tools: Abaqus and FlowVision through the direct coupling interface, which manipulates, on the Abaqus side the Lagrangian finite-element mesh and on the FlowVision side the Eulerian finite-volume mesh with subgrid geometry resolution.
Lift force formation in a thrust bearing of 800-tons rotor of electric power station is discussed in the given paper. The problem is solved numerically. Direct coupling between finite-element system Abaqus calculating stress and strain state of an bearing parts and finite-volume system FlowVision-HPC calculating oil flow in gap between a collar and a shoe of bearing is used. The shape of the gap between the shoe and the collar, the clearance value, the moment of the friction force, and the temperature distribution of oil over the clearance are determined.
Approach to numerical simulation of water and air flow around aquaplaning car tire is described. The approach for governing equations solving is based on a finite-volume method and non-staggered Cartesian adaptive locally refined grid. A method of subgrid geometry resolution is proposed for accurate
description of curvilinear complex boundaries. This method uses a presentation of boundaries as a set of plane facets and makes CFD code compatible with CAD systems. The described technology is implemented in FlowVision code. Some results of simulation of car tire aquaplaning performed by FlowVision are presented The tire lift dependence on a tread picture is calculated.