No abstract

No abstract

No abstract

No abstract

No abstract

Post ight analysis of the Mars Path nder hypersonic, continuum aerodynamic data base is presented. Measured data include accelerations along the body axis and axis normal directions. Comparisons of pre ight simulation and measurements show good agreement. The prediction of two static instabilities associated with movement o f the sonic line from the shoulder to the nose and back was con rmed by measured normal accelerations. Reconstruction of atmospheric density during entry has an uncertainty directly proportional to the uncertainty in the predicted axial coe cient. The sensitivity of the moment coe cient to freestream density, kinetic models and center-of-gravity location are examined to provide additional consistency checks of the simulation with ight data. The atmospheric density as derived from axial coe cient and measured axial accelerations falls within the range required for sonic line shift and static stability transition as independently determined from normal accelerations.

A brief review of the evolutionary progress in computational aerothermodynamics is presented. The current status of computational aerothermodynamics is then discussed, with emphasis on its capabilities and limitations for contributions to the design process of hypersonic vehicles. Some topics to be highlighted include: घ1ङ aerodynamic coeaecient predictions with emphasis on high temperature gas eaeects; घ2ङ surface heating and temperature predictions for thermal protection system घTPSङ design in a high temperature, thermochemical nonequilibrium environment; घ3ङ methods for extracting and extending computational aeuid dynamic घCFDङ solutions for eaecient utilization by all members of a multidisciplinary design team; घ4ङ physical models; घ5ङ validation process and error estimation; and घ6ङ gridding and solution generation strategies. Recent experiences in the design of X-33 will be featured. Computational aerothermodynamic contributions to Mars Pathaender, METEOR, and Stardust घComet Sample returnङ will also provide context for this discussion. Some of the barriers that currently limit computational aerothermodynamics to a predominantly reactive mode in the design process will also be discussed, with the goal of providing focus for future research.

No abstract