in some instances, it is inevitable that large amounts of potentially hazardous chemicals like chlorine gas are stored and used in facilities in densely populated areas. in such cases, all safety issues must be carefully considered. to reach this goal, it is important to have accurate information concerning chlorine gas behaviors and how it is dispersed in dense urban areas. furthermore, mainta...

Computational requirements of full scale computational fluid dynamics change as computation progresses on a parallel machine. The change in computational intensity causes workload imbalance of processors, which in turn requires a large amount of data movement at runtime. If parallel CFD is to be successful on a parallel or massively parallel machine, balancing of the runtime load is indispensab...

As the capabilities of computational fluid dynamics (CFD) to model full aircraft config­ urations improve, and the speeds of massively parallel machines increase, it is expected that CFD simulations will be used more and more to steer or in some cases even replace traditional flight test analyses. The mission of the US Air Force SEEK EAGLE office is to clear any new weapon con­ figurations and ...

a computational fluid dynamic (cfd) study of methanol (meoh) to dimethyl ether (dme) process in an adiabatic fixed-bed reactor is presented. one of the methods of industrial dme production is the catalytic dehydration of meoh. kinetic model was derived based on bercic rate. the parameters of this equation for a specific catalyst were tuned by solving a one-dimensional homogenous model using mat...

3D modeling of Pd/α-Al2O3 hollow fiber membrane by using computational fluid dynamic for hydrogen separation from H2/N2 mixture was considered in steady and unsteady states by using the concept of characteristic time. Characteristic time concept could help us to design and calculate surface to volume ratio and membrane thickness, and adjust the feed conditions. The contribution of resistance be...

Background Coronary atherosclerosis is common at vessel bifurcations. A quantitative approach to measuring blood velocity, vorticity and more complex flow features at bifurcations would enhance the understanding of the mechanisms of atheroma development, and potentially predict vessels at highest risk. The aim of this work was to validate 4D phase contrast (PC) magnetic resonance imaging flow m...

Computational fluid dynamic (CFD); Linearized two-dimensional transient flow (LTDT); Polar gridline transformation method. Abstract A novel derivation to transfer an actual domain with circular geometries to the computational domain, which is competent for application to computational fluid dynamics, is derived. Outcome formulas could be employed in cases of gridline transformation in the metho...

The process of synthesizing silica nanopowder by the gas phase thermal oxidation of tetraethylorthosilicate (TEOS) in a diffusion flame reactor was simulated using a commercial computational fluid dynamic (CFD) code. The fuel combustion process and silica particle formation and growth in the flame are modeled. The temperature, velocity and particle size distribution (PSD) fields inside the reac...