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Comparison of nonequilibrium solution algorithms applied to chemically stiff hypersonic flows
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Venkatapathy, Ethiraj Palmer, Grant |
| Copyright Year | 1995 |
| Description | Three solution algorithms, explicit under-relaxation, point implicit, and lower-upper symmetric Gauss-Seidel, are used to compute nonequilibrium flow around the Apollo 4 return capsule at the 62-km altitude point in its descent trajectory. By varying the Mach number, the efficiency and robustness of the solution algorithms were tested for different levels of chemical stiffness.The performance of the solution algorithms degraded as the Mach number and stiffness of the flow increased. At Mach 15 and 30, the lower-upper symmetric Gauss-Seidel method produces an eight order of magnitude drop in the energy residual in one-third to one-half the Cray C-90 computer time as compared to the point implicit and explicit under-relaxation methods. The explicit under-relaxation algorithm experienced convergence difficulties at Mach 30 and above. At Mach 40 the performance of the lower-upper symmetric Gauss-Seidel algorithm deteriorates to the point that it is out performed by the point implicit method. The effects of the viscous terms are investigated. Grid dependency questions are explored. |
| File Size | 726869 |
| Page Count | 12 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19970009856 |
| Archival Resource Key | ark:/13960/t8vb32s9t |
| Language | English |
| Publisher Date | 1995-07-07 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Heat Transfer Nonequilibrium Flow Robustness Mathematics Reentry Vehicles Hypersonic Flow Descent Trajectories Convergence Navier-stokes Equation Reentry Effects Algorithms Three Dimensional Flow Blunt Bodies Space Exploration Cray Computers Mach Number Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
