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The inner liner of a regeneratively cooled wall of a main stage rocket combustion chamber is extremely loaded by the high temperature of the hot gas and the pressure difference between the coolant and the hot gas. A cyclic operation of such a chamber usually causes a LFC failure of the wall structure after a very low number of cycles. For the tests presented in this paper, cyclic laser heating is (as replacement for the hot gas) applied to an actively cooled small section of the hot gas wall of the real engine -the so called TMF panel.Optical measurements during such TMF panel tests provide essential validation data for CFD, thermal, structural and fatigue life analyses: The 2d measurement of the thermal field of the heat loaded structure provides -together with the measurement of the temperature, pressure and mass flow rate of the coolant of the TMF panel -data for the combined validation of the CFD analysis of the coolant flow and the thermal analysis of the wall structure. The measurement of the deformation of the thermally loaded structure providestogether with the already determined temperature distribution and the above mentioned pressure measurements of the cooling channels -data for the validation of the structural analysis of the thermally loaded structure. Counting the number of laser loading cycles (laser on-off) until the TMF panel fails (by cracks appearing on the laser loaded side of the cooling channels) provides data for the validation of (either post processing or damage parameter based) fatigue life analyses of thermally loaded structures.

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A method for the optimization of rocket combustion chamber (combustion chamber) walls with respect to the life time is presented. This method can be split into four main parts: P1) Determination of the thermal field within the combustion chamber wall and the cooling channel during the hot run phase by a steady state thermo-fluid mechanical analysis; P2) Analysis of the nonlinear deformation of the combustion chamber wall under cyclic thermal and mechanical loading using a 2d plane strain or a 2d generalized plane strain model; P3) Estimation of the life time of the combustion chamber wall by a post processing method and P4) Application of a mathematical optimization procedure (gradient free or Conjugate Gradient method). This strategy is used to analyse the thermal load induced deformation process and life time of a typical rocket combustion chamber and to optimise selected geometry parameters of the combustion chamber wall.