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Rotational and vibrational nonequilibrium effects in rarefied, hypersonic flow
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Boyd, Iain D. |
| Copyright Year | 1989 |
| Description | Results are reported for an investigation into the methods by which energy transfer is calculated in the Direct Simulation Monte Carlo method. Description is made of a recently developed energy exchange model that deals with the translational and rotational modes. A new model for simulating the transfer of energy between the translational and vibrational modes is also explained. This model allows the vibrational relaxation time to follow the temperature dependence predicted by the Landau-Teller theory at moderate temperatures. For temperatures in excess of about 8000K the vibrational model is extended to include an empirical result for the relaxation time. The effect of introducing these temperature dependent collision numbers into the DSMC technique is assessed by making calculations representative of the stagnation streamline of a hypersonic space vehicle. Both thermal and chemical nonequilibrium effects are included while the flow conditions have been chosen such that ionization and radiation may be neglected. The introduction of these new models is found to significantly affect the degree of thermal nonequilibrium observed in the flowfield. Larger, and more widely ranging, differences in the results obtained with the different energy exchange probabilities are found when a significant amount of internal energy is included in the calculation of chemical nonequilibrium. |
| File Size | 735182 |
| Page Count | 11 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19900003182 |
| Archival Resource Key | ark:/13960/t4jm75g1j |
| Language | English |
| Publisher Date | 1989-01-01 |
| Access Restriction | Open |
| Subject Keyword | Aerodynamics Temperature Dependence Vibration Computational Fluid Dynamics Hypersonic Flow Rotation Monte Carlo Method Relaxation Time Hypersonic Vehicles Chemical Equilibrium Simulation Flow Distribution Mathematical Models Energy Transfer Nonequilibrium Conditions Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
