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This paper reports a computational fluid dynamics (CFD) study on influence of flow field on to gas residence time in boiler furnace. Specifically, investigated was secondary air nozzle direction influence on level of elimination of dead and recirculation zones.As residence time is a ratio between effective furnace volume and gas flow rate from the solid bed,increase of the former through elimination of dead zones would lead to increase of the residence time,and it as a consequence would have an increase of combustion efficiency. Small-scale biomass boilers are specific in a way that their...
Aerodynamics plays an important role in marketing vehicles especially with the recent increases in gas prices. The aerodynamics of one of the widely used vehicle classes (pickup trucks) is examined. The focus is to investigate the effect of the pickup truck configuration on the structure of the airflow around the vehicle and ultimately on the generated aerodynamic drag. The study includes CFD simulations performed using STAR-CCM+ developed by CD-adapco Inc. and full-scale wind tunnel testing conducted in the Langley Full Scale Tunnel (LFST) located at the NASA Langley Research Center but...
Advanced improvements in coupling methods of solid and fluid numerical softwares benefit considerably cardiovascular biomechanics investigations. Deformability of this complicated physiological system plays an important role in biofluid factors such as Wall Shear Stress (WSS). In the current work, taking advantage of recently developed bi-directional interaction tools between Abaqus and STAR-CCM+, a simulation of physiological pulsatile blood flow through aortic arch is implemented. Abaqus solves the computational solid mechanics problem corresponding to the arterial wall while STAR-CCM+ solves...
The capstone airplane design course at the University of Washington, two academic quarters long, has evolved in recent years to cover the airplane design experience from market and needs studies through conceptual design, preliminary design, and detail design, and up to the construction, ground testing, and flight testing of complex research-type small UAVs. Significant engineering resources are devoted to this effort including substantial CAD, CFD-based aerodynamics, NASTRAN-based structural analysis, as well as performance, and stability and control simulations. Wind tunnel tests of...
This paper presents a full coupled approach between fluid dynamics and structure analysis. It is conducted in order to further improve the assessment of fluid structure interaction problems, occurring in the nuclear field such as the behavior of PWR fuel rods, steam generators and other heat exchangers tubes, fast breeder fuel assemblies. The coupling is obtained by implementing a beam mechanical model in user routines of the CFD code STAR-CD, and thanks to a moving grid procedure. The configurations considered are rods in a cross flow. The model is first validated on a single rod case. The...
Successful transcatheter aortic valve (TAV) deployment and function are heavily reliant on the implant-host tissue interaction. Many adverse events observed clinically in TAV procedures such as impairment of coronary artery flow, paravalvular leak, and access site injury could be attributed to improper TAV deployment and interaction with the aortic root. In this study, we performed a computational analysis of the TAV-aortic root interaction, particularly the hemodynamics before and after TAV deployment. Utilizing a recently developed computational TAV model, we simulated the deployment of...
Subsea jumpers are steel pipe sections that connect hardware components on the seafloor (e.g. trees, manifolds, and sleds) and typically operate in multi-phase flow. They are designed with bends to accommodate limited expansion due to variations in temperature and pressure. Under certain conditions significant fluctuating forces can be induced in flow-turning elements like bends and tees. These fluctuating forces may cause severe piping vibrations and weld fatigue damage. This paper presents a flow-induced vibration screening procedure based on the 3-D numerical simulation of unsteady...

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