Computational Analysis and Characterization of the UTA 1.6 MW Arc-Heated Wind Tunnel Facility

Abstract

The present work focuses on a Computational Fluid Dynamics (CFD) investigation of the high-enthalpy flow produced by the 1.6 MW arc-heated wind tunnel facility of the University of Texas at Arlington. The numerical analysis is complementing a parallel experimental campaign dedicated to the aerothermodynamic characterization of the archeated plume originated by a nominal M=1.8 conical nozzle that has been used for the screening of candidate reusable C-C/SiC based materials for thermal protection system (TPS) applications. Due to dramatic changes in the thermo-mechanical response of the TPS when specific conditions of temperature, species composition, and pressure are reached, the knowledge of the flow conditions at the nozzle’s exit is an essential element for the identification of appropriate test conditions during the design of the experiment first, and the interpretation of the results later. Vibrational and chemical non-equilibrium conditions must be considered in the high-temperature nozzle flow when the characteristic times for the chemical reactions and vibrational energy are comparable to the characteristic flow time. The Navier-Stokes equations are solved with the implicit finite volume density-based solver of the commercially available CFD code Fluent. To solve the species equations two separate chemical kinetics models, the Park and Gupta models, are implemented in order to compare their results and performance in the current facility characterization. From the numerical characterization of the nozzle flow, new facility performance envelopes have been generated providing analytical correlations between the relevant aerothermodynamic parameters at the nozzle exit plane and the input facility operation conditions.