CRAFT Tech has been involved in rarefied flow simulation for over a decade. Our most recent work has pushed the state-of-the art to include six degree-of-freedom (6DOF) motion. Utilizing our in-house Direct Simulation Monte Carlo (DSMC) solver, we can now perform simulations of unsteady rarefied flow phenomena and their subsequent effect on objects. Rather than moving the simulation grid with the object, we perform cell cutting as the object moves through the grid. This point of view allows for multiple objects to be tracked within the same computational grid. Cell cutting is accomplished using an advanced and fully parallelized algorithm so the methodology is robust and efficient.
The example problem shows the influence of a 600 m/s, 5.0E18 molecules/m3 number density flow in a channel on a flat plate object. The plate reacts autonomously using the 6DOF equations of motion. Also shown is how our cell cutting technique defines the various cut-cells as the plate moves downstream.