Monte Carlo simulation for aerodynamic coefficients of satellites in Low-Earth Orbit

摘要

Fast and accurate prediction for aerodynamic coefficients of satellites in LEO (Low-Earth Orbit) is a fundamental prerequisite for the determination and control of orbit. Based on the test particle Monte Carlo (TPMC) method for the calculation of molecular flux rate through a pipe in vacuum technology, combined with the free-molecular theory, the TPMC method for the fast and accurate prediction of aerodynamic coefficients of satellites in LEO has been developed, with its main steps and important procedures presented. The method is validated by comparing the aerodynamic coefficients of a satellite with two solar panels with results from the DSMC (direct simulation Monte Carlo) technique and the panel integral method based on free-molecular flow theory. The case also indicates that the TPMC method is applicable to complex configurations in engineering. Results also shows that the TPMC method is capable of dealing with multiple reflections that the panel integral method cannot consider, resulting in an accurate aerodynamic coefficient. In addition, the CPU time and physical memory needed by the TPMC method is less than that of the DSMC technique by an order of 3-4 and 1 to 2, respectively, without compromising the solution accuracy, indicating that the TPMC is an ideal method for fast and accurate prediction for aerodynamic coefficients of satellites in lower LEO.