Aerodynamic Disturbances on Spacecraft in Free-Molecular Flow
Abstract
This report presents a thorough development of the aerodynamic forces and moments exerted on spacecraft at altitudes where the atmosphere is best described by free molecular flow theory. The gas-surface interaction model is based upon a combination of specular and diffuse reflection as characterized by normal and tangential momentum accommodation coefficients, while the random thermal motion of the atmosphere is described by the Maxwell-Boltzmann distribution law. In the case of non-rotating bodies of arbitrary shape, general expressions in the form of surface integrals are given for the aerodynamic force and moment. Complications due to spin are investigated for the class of axisymmetric bodies rotating about their axis of symmetry but with arbitrary orientation relative to the incident molecular flow. For several simple geometric shapes, the quadratures are performed analytically, and closed-form expressions are given for the aerodynamic force and moment. Graphs are generated showing the variation of the forces and moments with selected parameters, including the errors incurred by neglecting the random motion of the atmosphere.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 17, 2002
- Accession Number
- ADA410696
Entities
People
- J. A. Storch
Organizations
- The Aerospace Corporation