Estimation of one-dimensional high heat fluxes from surface temperature measurements using inverse solution techniques

摘要

Shock interactions such as those that occur during at-mospheric re-entry, can produce extreme thermal loads on aerospace structures. These interactions are reproduced ex-perimentally in hyper-sonic wind tunnels to study how the flow structures relate to the deleterious heat fluxes. In thses studies, the fuild jets created by shock interactions impinge on a test cylinder, where the temperature due to the heat flux is measured. These measurements are used to estimate the heat flux on the surface as a result of the shock interactions. Finding the boundary flux from discrete unsteady temperature measurements is characterized byinstabilities in the solution. The purpose of this work is to evaluate different inverse techniques as a proposed methodology for the determination of the unsteady heat flux. The performance of these methods is measured in terms of accuracy and their ability to handle inherently "unstable" or highly dynamic data such as step fluxes and high freqyency oscillating fluxes. The operational parameters associated with inverse techniques are also determined for this set of unique problems, and a new procedure called the New-Inverse technique was identified as the preferred methodology.