F.J. Krech, A. Spille, U. Salecker, B. Bosc-Bierne, M.K. Ben-Larbi, E. Stoll

Numerical simulations are essential ground based prediction tools for the aerodynamic and aerothermal analysis and design of reentry capsules. These methods are particularly important for analyzing effects that are not amenable to scaling and therefore difficult to replicate in wind tunnel tests. Such effects include the dissociation of air at high temperatures and thermodynamic non-equilibrium conditions. This study aims to simulate the airflow around the Atmospheric Reentry Demonstrator (ARD) at hypersonic speeds to reconstruct surface pressure, temperature values, and aerodynamic coefficients recorded during the ARD´s 1998 flight. Furthermore, it characterizes the effects of dissociation and thermodynamic non-equilibrium. Unlike post-flight analyses that derived simulation boundary conditions from dynamic pressure reconstructions based on flight data, this work uses the nrlmsise-00 atmospheric model for a purely predictive approach. This study utilizes the finite volume method implemented in Ansys Fluent based on the Reynolds-Averaged Navier-Stokes (RANS) equations, detailing the solution directives and mesh quality requirements. Two physical models are introduced: a perfect gas model which assumes constant gas properties and a real gas model based on the Park 93 chemical reactions of air. The real gas model utilizes a two-temperature model for thermodynamic non-equilibrium. Selecting four trajectory points from the ARD post-flight analysis where surface pressure and aerodynamic data are available, the study compares simulation results of both perfect and real gas models against flight measurements. The nrlmsise-00 atmospheric model provides boundary conditions for density, pressure, and temperature, implementing a predictive approach. Findings indicate that the finite volume method in Ansys Fluent effectively reconstructs surface pressure and aerodynamic coefficients, revealing significant real gas effects. Moreover, the study successfully replicates the oscillation frequency that was observed during the flight.

Deutscher Luft- und Raumfahrtkongress 2024, Hamburg

Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn, 2024

Conference Paper

englisch

21,0 x 29,7 cm, 18 Seiten

urn:nbn:de:101:1-2411251431142.425218049944

10.25967/630357

CFD, Atmospheric Reentry Demonstrator, FVM, Real Gas Effects

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Krech, F.J.; Spille, A.; et al. (2024): Numerical Simulation of the Hypersonic Airflow around the Atmospheric Reentry Demonstrator (ARD) Capsule. Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V.. (Text). https://doi.org/10.25967/630357. urn:nbn:de:101:1-2411251431142.425218049944.

25.11.2024