Research Directions in Computational Mechanics (1991) / Chapter Skim
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12 General Computational Fluid Dynamics
12 General Computational Fluid Dynamics
Pages 115-121
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From page 115... ...
Aerodynamics, numerical weather prediction, acoustics and fluid-structure interaction, propulsion systems, and nuclear reactor design are among the major applications that have encouraged CFD research. In the aerodynamics field, particularly aircraft design, CFD was originally regarded merely as a complement to wind tunnel experiments, essentially limited to the simulation of incompressible potential flow.
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From page 116... ...
Additionally, difficulties in modeling pure convection phenomena still exist and researchers point to open questions that remain in developing reliable Euler codes for unsteady three-dimensional flows. The analysis of propulsion systems, such as the space shuttle main engine and cooling systems for nuclear reactors, has encouraged much research on new efficient incompressible viscous flow simulators.
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From page 117... ...
Here the Navier-Stokes equations may not be applicable, although some success in predicting gas flow in this regime has been achieved by solving the Navier-Stokes equations with modified boundary conditions. When the mean free path is large compared to the characteristic body length, the flow regime is said to be "free molecule." This is an environment, experienced by orbiting vehicles, where molecules are observed as discrete particles.
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From page 118... ...
Central to this approach is the problem of establishing the correct flux terms at cell boundaries. In computing these fluxes, either flux splitting or flux difference splitting schemes are used with modern upwind methods.
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From page 119... ...
The complex modeling requirements and delineation of the various flight regimes lead one to question several current approaches used to solve the equations governing fluid flow, particularly in low-density hypersonics.
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From page 120... ...
For some flow problems involving complicated physics and/or rarefied gas, simulation methods based on Boltzmann equations and Monte Carlo particle methods seem quite appropriate. Indeed, impressive results have been obtained by Japanese investigators using a Boltzmannequation-based method to simulate multidimensional hypersonic flow.
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From page 121... ...
With increased performance demands for modern submarines, simulation of acoustical scattering and radiation in complex submerged deformable bodies has emerged as a crucial research area. Today, realistic computer simulations of acoustical phenomena connected with moving submarines is impossible, and several breakthroughs must be made before these very large scale problems can be treated with confidence.
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