Coupling Of Gas Surface Interaction And Material Response In Hypersonic Ablation

Download or read book Coupling of Gas-surface Interaction and Material Response in Hypersonic Ablation written by Guangwei Liu and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Hypersonic flight has seen a considerable resurgence of interest over the past two decades. Several unique physical phenomena occur in this ultra-high-speed regime, one of them being a bow shock appearing in front of the vehicle. There is a rapid increase in temperature across this thin shock layer that imposes high heat loads on the windward surface of the aircraft. Thermal Protection Systems are therefore crucial to prevent heat damage. Such systems consist of a layer of insulation covering the craft's surface. Experimental trials on Thermal Protection Systems are complex, expensive, and difficult to repeat because of the hypersonic flow conditions and shape of the vehicles. CFD can complement experiments by providing reliable predictions for a wide range of operating conditions and complex geometries. It is thus the most viable approach at the design stages.The present work extends the capabilities of the HALO3D (High Altitude Low Orbit, 3D) hypersonic flow simulation software to predict the surface ablation behavior along the re-entry trajectory of a vehicle. A loosely coupled model is established to consider the thermochemical non-equilibrium of the flow field and heat transfer inside the solid protection layer. The gasdynamic equations of chemical-thermal non-equilibrium air and the heat conduction in the solid material are solved separately and loosely coupled to increase computational efficiency. The surface chemistry is solved involving the gaseous reactant from the Thermal Protection Systems as well as chemical non-equilibrium conditions. The gas-surface interactions are simulated with a quasi-steady assumption. By contrast, the material response is solved transiently and coupled with gas-surface interaction results through interface boundary conditions. The computational grids of both fluid and solid domains are updated at every trajectory point.The surface chemistry solver is verified and validated with various freestream temperatures and pressures. The coupling between gas-surface interaction and material response is verified through one-dimensional heat transfer. The loosely coupled ablation approach is first validated for a rocket engine blast pipe with given surface regression rates and temperature-dependent material properties. The capabilities of the proposed coupling methodology are then demonstrated for a scenario of hypersonic flow over a half-cylinder"--