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Specific rendering modes are developed for a combined visual/haptic interface to allow exploration and understanding of fluid dynamics data. The focus is on visualization of shock surfaces and vortex cores. Advantages provided by augmenting traditional graphical rendering modes with haptic rendering modes are discussed. Particular emphasis is placed on synergistic combinations of visual and haptic...
Based on the current widespread use of underwater vehicles, a special type of underwater glider equipped with energy-saving diamond-structured rotatable wings that can improve the underwater vehicle's lift-drag ratio optimize hydrodynamic performance, and enhance flight quality was studied. With the support of adaptive meshing technology and Fluent's epsilon standard turbulence model, lift and drag...
In order to accurately control the portable AUV, a dynamic modeling method based on computational fluid dynamics (CFD) and a improved Generalized Predictive Control (GPC) method were presented. First, the whole modeling process was described from two aspects: dynamic model derivation and model parameter identification. Second, the validity of the model and modeling method were tested by comparing...
Podded propeller (POD) has been developed recently as a new type of propulsion system. It is composed of a pod body, a propeller, and a strut. This propulsion system can save cabin space, reduce vibration of the main engine, increase propulsion efficiency, and improve the ship maneuverability. This study verifies the reliability of computational fluid dynamics (CFD) for calculating the hydrodynamic...
In this study, the effects of fin stroke phase offset, fin position offset, and flapping frequency on thrust production are investigated for tandem pectoral fins. Two different fin geometries are considered, one rectangular and one bio-inspired. Experimental results are supported with computational fluid dynamics (CFD) simulations, validating the experimental methods as well as the computational modeling...
In this study, numerical investigations of flow characteristics of a pumpjet propulsor based on Computational Fluid Dynamics (CFD) method have been presented. The Zwart-Gerber-Belamri (Z-G-B) cavitation model based on the Reynolds Averaged Navier-Stokes (RANS) method is employed. The structured gird is applied. A four-blade skewed E779A propeller has been used to verify the numerical method. The comparison...
This paper presents the motion simulation of an autonomous underwater helicopter (AUH), a new type of underwater vehicle proposed by Zhejiang University. In order to determine whether its controllability meets the design requirements, a singularity-free unit quaternion stable control method is used for simulating the AUH performance in MATLAB, including its force and trajectory under different types...
In order to analyze the dynamic performance of a Remotely Operated Vehicle (ROV) during mission like ship hull inspection, it is necessary to establish the 6 degree-of-freedom equations of motion considering well modeled hydrodynamic force acting on a ROV. Typically, the hydrodynamic force is the model by polynomial functions and those coefficients are obtained by captive model tests or empirical...
The underwater vehicles are always being disturbed by ocean current when they work under the sea. In this paper, the Magnus force of a new type autonomous underwater vehicle (AUV) named “autonomous underwater helicopter (AUH)”, a disk-shaped deep-sea underwater vehicle, was analyzed to help it move away from a deep-sea region with temporary ocean current. The simulation technique of the ANSYS-CFX...
The gravitational water vortex power plant (GWVPP) is a new type of low head turbine system in which a channel and basin structure is used to form a vortex, where the rotational energy from the water can be extracted through a runner. This study is focused on the optimization of the runner to improve the efficiency of the GWVPP. Computational fluid dynamics (CFD) analysis is carried out on three different...
Coronary artery disease (CAD) is the most common cause of death globally. Typically, it occurs when part of the coronary artery develops atherosclerosis, which causes the narrowing of the vessel lumen. The decision to be taken to treat the stenotic artery vessel is often influenced by several factors. The aim of this study is to develop an application (app) to provide support to the physician in decision-making...
SimVascular is an open source software platform for cardiovascular simulation, providing a complete pipeline from medical image data to volumetric model construction, meshing, and blood flow simulation. Previous workshops and educational programs have utilized SimVascular, but learning assessments have not been used to rigorously quantify gains in conceptual understanding. Goal: The purpose of this...
This paper studies the influence of three volute geometries of a single-stage centrifugal compressor, using the same vaned diffuser and impeller, the only differences are given by the volute geometry: cross section area and volute tongue. The objective of this research is to determine which of parameters has a major impact on the compressor and how much are the operating range and overall performance...
Indoor Environmental Quality (IEQ) in healthcare facilities represents a major problem for the health and safety of the patients and the medical team, especially in critical areas like operating rooms (ORs). Another major problem in this area is the thermal comfort which is felt differently by the occupants, due to the different activities that they have or due to the different level of clothing....
This paper investigates the performance of ejectors with a streamline structure. The parabola fitting is adopted to simulate the ejectors streamline structure and the effects of parabola fitting structure on ejectors are studied using the Computational Fluid Dynamics (CFD) technique. The contrast simulations of the parabola models and the original model are conducted in which the entrainment ratio...
We proposed a liquid immersion cooling technology with natural convection for high power server boards used in data centers with high cooling-efficiency. The cooling performance was evaluated by CFD simulation and actual experiments. As the refrigerants, several non-conductive, thermally and chemically stable fluids were applied, including silicone oil, soybean oil, and perfluorocarbon structured...
Enhancing the performance of turbulent flow simulations is important as the size of simulations grows with higher Reynolds number. We discuss the performance of our in-house turbulent flow simulation solver, named as DNS-TBL (Direct Numerical Simulation: Turbulent Boundary Layer), on the Intel Xeon Phi™ manycore processors. With bootable Knights Landing processors, the DNS-TBL solver shows excellent...
The paper investigates a thermal behaviour of a DC inductor deployed in a 600 kW power converter for particle accelerators. The inductor is manufactured from electrical steel core and two magnetically coupled windings with integrated air ducts for enhanced air circulation. The thermal analysis of inductor are carried out by means of a Computational Fluid Dynamics (CFD) model and simulations. The paper...
Whereas the use of flow diverter stents (FDs) represents a powerful treatment alternative to surgical clipping of intracranial aneurysms (IAs) presenting at arterial bifurcations, endovascular deployment of FDs often involves the jailing of daughter vessels (DV), and can affect the patency of the jailed DV.
The purpose of this study was to investigate the accuracy and precision of fast plane wave 2-D vector flow imaging (VFI) under laminar and complex flow conditions in a human subject. The method has previously been validated in simulations and straight-vessel phantoms, however, complex flow patterns remain challenging to study, since there are no other imaging techniques accurately enough to compare...
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