Effect of Concave Wall Geometry on Heat Transfer in Hypersonic Boundary Layers
Heat transfer measurements are made to investigate the effects of concave surface curvature on a high-stagnation enthalpy boundary layer in a Mach 5.1 flow. Experiments are 
carried out using two curved models with 16 and 25 degree turning angles, and baseline 
planar models (at plate and linear ramp) for comparative study. Streamwise and spanwise 
cross-sections are obtained. Significant destabilization of the boundary layer is observed 
over the adverse pressure gradient geometries. For the curved surfaces, the heat flux distribution appears to exhibit a quadratic dependence with streamwise distance, in contrast 
with the linear dependence observed on the linear ramp.
Diagnostic modelling of an expansion tube operating condition
Computational simulations of an expansion tube were conducted to estimate flow parameters and verify experimental uncertainties. Two types of simulations of the complete facility were undertaken: a one-dimensional simulation, and a hybrid simulation where a one-dimensional simulation of the shock tube section was coupled with a two-dimensional simulation of the acceleration tube. Good agreement between the one-dimensional simulations and experiments were obtained in the shock tube portion of the facility. In the acceleration section, initial two-dimensional simulations did not match the experimentally measured pitot pressure and showed a discrepancy in the shock speed. Further studies examined how the accelerator gas composition affected shock speed, static pressure and pitot pressure levels in expansion tube operation. Subsequent two-dimensional simulations, using an 8% level of air contamination in helium, showed reasonable agreement with experimental data. This prediction of air contamination was later confirmed with experimental measurements of the air partial pressure before operation.
Shock Tube Modelling With L1d
L1d is a computer program for the simulation of transient-flow facilities such as light-gas launchers and free-piston driven shock tunnels. The numerical modelling embodied within L1d is based on a quasi-one-dimensional Lagrangian description of the gas dynamics coupled with engineering correlations for viscous effects and point-mass dynamics for poston motion. This report describes the governing equations and a set of four example simulations: * Sod's classic shock tube problem; * a ideal gas gun; * a fixed-driver shock tunnel; and * a free-piston driven shock tunnel.