New Thermal Sensors for Use with Inverse Heat Conduction Problems

"Inverse heat conduction involves the application of diffusion theory for estimating unknown boundary conditions, energy generation, rates, or thermophysical properties from measured temperatures or heat fluxes at other locations. Inverse problems are saidto be ill-posed in that small errors in the data can produce randomly large variations in the prediction. It has recently been shown that the available of reliable measurements of the rate of change of temperature or heat flux with time can, inconjunction with temperature or heat flux data, provide much more reliable predictions than those obtained using the latter data alone. Unfortunately, there are no reliable sensors available for direct measurement of the rate of change of temperature orheat flux. It is proposed to develop such sensor designs, model their performance, develop simulation tools and error analyses, identify fabrication technologies, and develop plans for verification of sensor performance The sensors to be developed will beof critical importance in experimental investigations of heat conduction problems where the data must be analyzed by inverse heat conduction techniques, such as predicting what energy inputs at an inaccessible surface produced a measured response at anaccessible surface. Examples include a structure subjected to a directed energy beam, surface conditions in the interior of a rocket or jet engine, or structures subjected to fire or explosion.