Design to Validation of a New Heat Flux Source with Uncertainty Analysis

Abstract

High-speed, transient aerothermal studies produce excessive temperatures and heat fluxes in laboratory, ground, and flight-test experiments. Experiments are performed for 1) understanding the response of test vehicles under various induced thermal environments, 2) verifying computational codes and input parameters, and 3) evaluating thermophysical and mechanical characteristics of new materials. In addition to these rationales, the reconstruction of the surface heat flux from in-depth or backside instrumentation is an important inverse application. Recent research has led to an alternative view of inverse heat conduction based on calibration principles performed in the frequency domain leading to a novel “parameter-free” inverse heat conduction measurement equation. The final mathematical framework reveals that the resolution of a first-kind Volterra integral equation for the surface heat flux prediction contains only experimental data sets. This type of mathematical formulation is highly ill posed. This paper focuses on the design, fabrication, and preliminary test campaign of a new electrical heating cell for producing a verifiable heat flux source. The feasibility investigation demonstrates the merits of system through modeling, experimental design, and transient uncertainty propagation. Validation studies are presented, leading to favorable outcomes. Slug calorimetry, composed of a pure copper, is used in the validation campaign.