Numerical Investigation of Unsteady Heat Transfer on a Double Wedge Geometry in Hypervelocity Flows

Abstract

In recent experiments performed at the University of Illinois, nitrogen and air flows over a double wedge geometry at Mach numbers varying from 4-7 and stagnation enthalpies varying from 2.1-8.0 MJ/kg were investigated. Selected cases from these experiments are simulated using US3D to ascertain the ability of state-of-the-art finite-volume hypersonic flow solvers to replicate experimental results. Two-dimensional simulations predict an unsteady separation and shock-shock interaction under both reacting and non-reacting conditions. The numerical solutions reach a time-periodic solution for certain experimental conditions. Good agreement is observed between experiment and two-dimensional simulations of the Mach 7 flow conditions when the simulations are limited to the experimental run-time. When run to a large number of flowtimes, the agreement is poor. Three-dimensional simulations of these free-stream conditions show non-uniformities in the wedge boundary layer during flow development.

Shock Wave Laminar Boundary Layer Interaction Over a Double Wedge in a High Mach Number Flow

“…Recent results subsequent to this research by Komives et al [18], and Tumuklu et al [19] indication that the experimental flow field is fully three-dimensional.…”

Experimental and Numerical Study on Hypersonic Flow over Double-Wedge Configuration

“…Komives et al [13] conducted a numerical study on unsteady heat transference with double-wedge geometry; their results showed reasonable agreement with the experimental heating results, apart from some differences between the predicted and experimental flow structures. Later, researchers conducted a study on double-wedge geometry for which the first wedge angle was 9 deg and the second wedge angle was 20.5 deg [14].…”

Modeling of near-continuum laminar boundary layer shocks using DSMC

“…In contrast, the 3D flowfields were found not to change significantly after 140,000 time steps (140µs), hence, a maximum of 200,000 and 100,000 time steps was computed the experimental and density decreased case, respectively. Even though the DSMC method is inherently time accurate, as compared to past continuum CFD approaches applied to the problem of interest [7,8], the initial flow transients that occurred in the experiments were not modeled here. For the experimental case, the macroparameter sampling was started at 30,000 time step, and conducted in 40,000 increments between 40,000 and 200,000 steps and finally 100,000 increments after 200,000 step in order to observe the flow transients in the DSMC solution.…”

“…These experiments have motivated a number of recent numerical studies using continuum CFD [7,8] and Direct Simulation Monte Carlo (DSMC) [9] approaches and are part of the NATO RTO-AVT 205 program in the Assessment of Predictive Capabilities for Aerothermodynamics Heating of Hypersonic Systems. In this study, the high-enthalpy nitrogen case is considered and the flow conditions are presented in Table 1.…”