Convective heat-transfer rate and surface pressure distribution over a cone model at hypersonic speeds

In this article, experiments are carried out in a hypersonic shock tunnel with helium as driver gas and air as the test gas to obtain the convective heating rate and surface pressure distribution on a cone model placed at hypersonic speed. Test is performed in hypersonic shock tunnel for a flow Mach number of 6.5 at two different angles of attack, 0° and 5°. The sputtered thin film platinum sensors are used to measure the heat flux on a cone model. The measured heat-transfer rate compares well with theoretically estimated values using reference enthalpy method and computational fluid dynamics (CFD) simulation. The measured surface pressure compares well with CFD.

Velocity and NO-Lifetime Measurements in an Unseeded Hypersonic Air Flow

A laser-induced fluorescence (LIF)-based nitric-oxide flow-tagging technique was applied to measure both velocity and NO lifetime in a hypersonic shock tunnel from two experimental test runs. The results were supported by an analytical profile proposed in this paper that provides a way to correct velocity measurements under unknown systematic error sources. This procedure provided velocities with discrepancies lower than 3% for a total of five measurements, and lower than 2% when compared with that obtained from a linear fit. Additionally, the comparison between the proposed and experimental profiles allowed us to obtain the fluorescence NO lifetime from only one image.