Improving a spacecraft’s return to Earth

Extremely high temperatures are generated when a hypersonic aircraft reenters the Earth’s atmosphere. Chemical and ionization reactions result, leading to a communication blackout and severe surface thermal effects on the craft.

An alternative to traditional reentry vehicles, called inflatable membrane reentry vehicles (IMRVs), possess advantages including lighter weight, faster deceleration, lower landing impact, and a lower ballistic coefficient. However, these new crafts remain susceptible to high temperatures that cause structural damage and communication problems.

To aid in the optimal design of IMRVs, Yu et al. developed a model for simulating the high-temperature air plasma movement around the aircraft.

“A reduced chemical kinetic model of air was integrated into a 3D computational fluid dynamic model for simulating the nonequilibrium plasma flow around a hypersonic reentry spacecraft,” said author Minghao Yu.

Simulation results show that the flight stability of an IMRV is highly dependent on the angle of entry. At 0°, the wall pressure and heat flux gradually decrease from the head of the capsule to the inflatable film, increase where the film joins the rings, and decrease again after moving over the shoulder. Compared to experimental data, the new 3D model showed high prediction accuracy and a lower computational cost approach for air plasma simulations using relatively simple chemical reactions.

The team plans to simulate membrane deformation characteristics at different flight speeds and experiment in a plasma wind tunnel.

“We hope to uncover the maximum membrane deformation that the IMRV can withstand to prevent membrane damage,” said Yu.

Source: “A three-dimensional thermochemical nonequilibrium model for simulating air plasma flows around an inflatable membrane reentry vehicle,” by Minghao Yu, Wei Wang, Zhiqiang Hu, and Bo Wang, Physics of Fluids (2024). This article can be accessed at https://doi.org/10.1063/5.0217059 .