Pierre Van Hauwaert
DOI Number XXX-YYY-ZZZ
Conference Number HiSST-2022-0244
A Direct Simulation Monte Carlo (DSMC) code is presented with its validation and its applications. The code uses a cut cell approach combined with an on-the-fly Cartesian grid adaptation. The simulation is distributed using the MPI protocol and has the ability to rebalance the computation loads through the simulation. Validation of the code is demonstrated. Over 3400 simulations are carried out on 105 geometries in order to compute the random tumbling drag and heat rate in the transitional regime. The simulation setup to obtain reliable DSMC results in an automated way is outlined. Simulation results are compared with an approximation model. In order to compute the dimensionless random tumbling coefficients characterizing both the drag force and the heat rate, the random tumbling average of the projected shape is selected as reference surface. A formulation that can be applied to various topologies of object is used as a basis for the characteristic length used to define the average Knudsen number and for the equivalent radius used in the approximation model that computes the heat rate. For the 105 cones and cone-segments investigated, parameters can be selected such that the average difference between the approximation model and the DSMC results are below 1% for both drag and heat rate.