Inverse prediction of wall temperature distribution on a cylinder exposed to radiatively active flow

In this study, the unknown wall temperature profile of a cylinder was predicted by applying the inverse method. The temperature profile of the cylinder wall was predicted from the given temperature data at measurement points near the cylinder wall. The cylinder was assumed to represent a typical pipe in a bundle of heat exchange tubes operating in a high temperature system. Radiative heat transfer was incorporated as one of major heat transfer modes to consider a hot gas flow passing over the cylinder. The corresponding inverse problem was solved by minimizing an objective function by applying the iterative conjugate gradient method. A multi-block grid composed of three different blocks was used for better computational accuracy and convenience in locating the measurement points. A new method, which could be applicable to non-symmetric geometry, was adopted to solve the adjoint equation. In this study, the effects of number and location of the measurement points were numerically investigated. When the measurement points were too close to the cylinder, the predicted temperature profile exhibited larger fluctuations. The results have also shown that an appropriate number of measurement points were required to improve the prediction of the boundary temperature profile.