Inflatable aerodynamic decelerator for CubeSat reentry and recovery: Altitude effects on the flowfield structure

In the present investigation, numerical simulations are conducted in order to characterize the flowfield structure of Inflatable Aerodynamic Decelerators (IAD) for CubeSat reentry and recovery. IAD may inflate to its full size before the reentry procedure, and it can be used to reduce the velocity and protect the CubeSat against the harsh reentry environment. In addition, by protecting the CubeSat during the reentry, it will be possible to recover and reuse part of it in several missions. In the present investigation, a CubeSat coupled with an IAD system is investigated for altitudes ranging from 115 to 95 km. Due to the considerable degree of rarefaction at these altitudes, the Direct Simulation Monte Carlo Method was employed to compute the macroscopic properties around the nanosatellite. According to the computational results, it was observed the formation of a highly diffuse shock wave upstream of the IAD at 115 km. As the CubeSat moves through an ever-thickening atmosphere, a significant increase in the shock wave temperature, pressure, and density measured along the stagnation streamline was noticed. As the flow expands over the IAD shoulder, the wake region is characterized by a significant decrease in the macroscopic properties, and no recirculation region was formed for the altitudes considered in the present investigation.