Estimating Drag and Heating Coefficients for Hollow Reentry Objects in Transitional Flow Using DSMC

Marichalar, Jeremiah J ; Ostrom, Chris L

关键词: AERODYNAMIC COEFFICIENTS;    AERODYNAMIC DRAG;    AEROTHERMODYNAMICS;    COMPUTERIZED SIMULATION;    CONTINUUM MECHANICS;    FREE MOLECULAR FLOW;    GAS FLOW;    MATHEMATICAL MODELS;    MONTE CARLO METHOD;    RAREFIED GAS DYNAMICS;    SPACE DEBRIS;    STATISTICAL ANALYSIS;    TRANSITION FLOW;   

RP-ID  :  JSC-E-DAA-TN73960

学科分类：空间科学

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

In NASA’s Object Reentry Survival Analysis Tool (ORSAT), aerodynamic drag and aerothermal heating coefficients are computed for each of the free-molecular, continuum, and transitional flow regimes using analytical and semi-analytical methods. These methods are typically limited to convex, blunt objects (such as spheres) and are applied to other objects such as boxes and cylinders using multiplicative “shape factors” to account for the different behavior. Previous literature has analyzed the aerodynamic and aerothermodynamic properties of flow around sharp-edged objects like boxes and cylinders in transitional flow, though only those objects with solid external boundaries. However, many reentry objects we have encountered in real spacecraft have been hollow (i.e., with the potential to allow flow through them). We present here preliminary results from analyses performed using the NASA Direct Simulation Monte Carlo (DSMC) Analysis Code (DAC) on hollow cylinders and boxes (with varying wall thickness-diameter ratio).