Experimental lifetime study of regeneratively cooled rocket chamber walls

A detailed knowledge of the life-limiting mechanisms of regeneratively cooled rocket combustion chambers is important to increase the safety, the thrust-to-weight ratio and the cost-efficiency of future rocket engines. For this purpose, an actively cooled specimen made of CuCr1Zr is mounted downstream of a combustion chamber. The specimen is loaded cyclically and inspected after each cycle. The specimens collapse in the 'doghouse' failure mode after several load cycles. The effects of different hot-gas and coolant conditions, surface roughness and thermal barrier coatings on the lifetime are studied. The life-limiting mechanisms: creeping, yielding, abrasion, blanching and thermal aging are discussed.