Low speed numerical and experimental validation of a solving methodology for the inverse heat conduction problem by means of quantitative infra-red thermography

The presented paper deals with the solution of the Inverse Heat Conduction Problem (IHCP) through the use of quantitative Infra Red thermography (QIRT) and proposes a solving methodology for the IHCP as a "ill-posed" problem. To solve the IHCP the surface temperature of a heat conducting body is used as boundary condition after measurement by means of an I.R. camera. The proposed methodology is first tested numerically and, subsequently, experimentally on a heated flat plate in a low subsonic speed wind tunnel. The "ill-posed" nature of the IHCP translates into a high sensibility to measurement errors, possibly leading to non-unique solutions. To reduce this sensibility a ridge regression based regularization methodology is proposed. Near-wall and free flow boundary conditions are imposed using Constant Temperature Anemometry (CTA). Results show good agreement between the proposed IHCP solution and reference cases, both for the numerical and the experimental analysis. Moreover, the proposed regularization applied for the experimental analysis is shown to enhance the accuracy of the obtained solution of the IHCP.