Transcatheter aortic valve replacement (TAVR) is a minimally invasive procedure that provides an effective alternative to open-heart surgical valve replacement for treating advanced calcific aortic valve disease patients.
However, complications, such as valve durability, device migration, paravalvular leakage (PVL), and thrombogenicity may lead to increased overall post-TAVR morbidity and mortality. A series of numerical studies involving a self-expandable TAVR valve were performed to evaluate these complications. Structural studies were performed with finite element (FE) analysis, followed by computational fluid dynamics (CFD) simulations, and fluid–structure interaction (FSI) analysis.
The use of numerical simulation and advanced means of computational hydrodynamics (domestic FlowVision software) for simulating the processes of flow and combustion in the systems for air and gas feeding, mixers, burners, and boiler furnaces has made it possible to advance the recirculation system and burners of the TETs-21 cogeneration plant and considerably reduce the NOx emissions.
Validation of FlowVision CFD on ICCS2015 Test Case: Application of Gap Model and SGGR for Leakage Flow Prediction in a Dry Screw Compressor
Clearances and leakages through them play a vital role in determining the efficiency of positive displacement machines, especially of screw compressors. It is of interest to accurately predict the overall machine behavior including the leakage flows, even during the early design phases. CFD (Computational Fluid Dynamics) methodologies can potentially address this problem; however, the computational efficiency is limited by the well-known issue: dimensionality. This issue arises due to the fact that rotors are sized in tens of centimeters whereas the clearances are in the order of (sub) microns.
Certifying a transport airplane for the flights under icing conditions requires calculations aimed at definition of the dimensions and shapes of the ice formed on the airplane surfaces.Up to date, software developed in Russia for simulation of ice accretion and authorized by Russian certifying supervisory authority, is absent.
The paper describes methodology IceVision recently developed in Russia for calculations of ice accretion on airplane surfaces. This methodology is implemented in CFD software FlowVision used by numerous companies and universities in Russia and abroad.
Transcatheter aortic valve replacement (TAVR) has emerged as a life-saving solution for inoperable elderly patients with end-stage calcific aortic valve (CAV) disease . However, valve migration, paravalvular leakage (PVL), and thrombogenic potential may limit its expansion into younger, lower-risk patients . Previous numerical studies attempted to address these complications but neglected the valve post-deployment performances during heart beating . This study utilizes Simulia Living Heart Human Model (LHHM) heart beating capabilities coupled with a fluid-structure interaction (FSI) simulation to evaluate TAVR complications.
Scalability of computations in the FlowVision CFD software on the Angara-C1 cluster equipped with the Angara interconnect is studied. Diﬀerent test problems with 260 thousand, 5.5 million and 26.8 million computational cells are considered.
CFD package “Flow Vision” has been developed since late 1960th and now is one of the mostly used in Russia and elsewhere, In the present report we describe the applications of the “Flow Vision” for hypersonic vehicles (HV) design, Imitation modeling and optimizations. We describe and use it for external aerodynamics, simulations of inlets, fuselages, wings, combustion chambers and nozzles. We simulated HV for different models like “Hexafly”, X01-MIPT and other vehicles at the laboratory of Hypersonic and Plasma Technologies of Moscow Institute of Physics and Technology.
Design and CFD Analysis of a 150kW 8-Stage ORC-ROT (Organic Rankine Cycle-Radial Outflow Turbine) and Performance Degradation due to Blade Tip Clearance of Labyrinth Seal
In this study, blade tip leakages were calculated for aIn this study, blade tip leakages were calculated for a Radial Outflow Turbine (ROT) designed for an Organic Rankine Cycle (ORC) at a 150kW power output. Since the turbine blade sizes are relatively very small for low-capacity systems, the leakages through the blade tip clearance considerably affect the turbine isentropic efficiency. Therefore, labyrinth seals were applied at the blade tips and the ROT’sperformance degradation due to blade tip leakages was investigated. In order to determine the preliminary ROT sizes, an in-house developed 1-D code was utilized.
Fluid-Structure Interaction Simulation of Artificial Textile Reinforced Aortic Heart Valve: Validation with an In-Vitro Test
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.
Blood Flow Modeling in a Beating Human Heart with Appliccations in Medical Device Design and Patient Care
Cardiovascular disease remains the leading cause of death in Cardiovascular disease remains the leading cause of death in developed countries. After the introduction of stents in the 1980s mortality rates declined, yet those gains have since plateaued, signaling the need for a new generation of treatments that are safer and more effective. To achieve this goal, it is important to understand both the physical device-body interaction as well as the physiological changes induced by the device.
Computational tools are uniquely capable of accounting for cardiac/vascular tissue mechanics, blood flow, and the interaction between them, yet are currently under-utilized due to their complexity. The SIMULIA Living Heart Model (LHM), an anatomically and physiologically realistic 3D model of a human heart, provides a platform to better understand the human heart in healthy and diseased states as well as to improve the efficacy of cardiovascular medical devices and to guide the clinical treatment of heart disease. In this paper, we focus on the modeling of blood flow which encompasses a wide variety of conceptual and technical approaches. These range from 0D/1D lumped parameter models (LPMs) of the cardiovascular system to highly detailed 3D fluid-structure interaction (FSI) co-simulations.Using applications from medical device design and patient care, we discuss best practices in the context of the problem being modeled and the level of accuracy desired.
INVESTIGATION OF THE FLOW AND NOISE DISTRIBUTION ON A BLOWER VIA INTEGRATION OF SIMULATION AND EXPERIMENTS
As the consciousness of energy saving and carbon reduction and comfortable environment is paid increasing attention to, the common objective of various countries with decreasing energy is to develop and popularize high efficiency and low running noise blowers. This study uses CFD to calculate the flow field and performance of a blower and compare with the experimental measurement.
The characteristic curve of blower shows that the simulated and experimental values are close to each other, the difference between the values is only 0.4%. This analysis result proofs the CFD package is a highly reliable tool for the future blower design improvement. In addition, this study discusses the noise distribution of blower flow field, the periodic pressure output value calculated by CFD is used in the sound source input of sound pressure field, so as to simulate and analyze the aerodynamic noise reading of the flow field around the blower. The result shows that the simulated value of flow field around the fan has as high as 80.5 dB(A) ~ 81.5 dB(A) noise level and is agree with measurement (82 dB(A)). The noise level is low but has a sharp noise. According to the numerical results, designer of the blower modify the tongue geometry and remove the sharp noise.