Thermomechanical Response Analysis of Regenerative Cooling Channel for Rocket-Based Combined-Cycle Engine

The multi-modal and wide speed range characteristics of combined cycle engine make the combustion chamber face extremely harsh thermal load. Active regenerative cooling technology is widely used in the current thermal protection system. This paper presents a thermomechanical response analysis of regenerative cooling channel for RBCC engine. The thermal load spectrum of the regenerative cooling combustion chamber is obtained by means of detailed simulations. Then the cyclic stress analysis of the regenerative cooling channel is carried out using Chaboche nonlinear kinematic hardening plasticity model based on finite element method. The results show that the trailing edge of the concave cavity of the combustion chamber is the location with the largest thermal load and the largest residual strain, indicating the most possible place where failure will occur. As the number of thermal cycles increases, the strain development in the cooling groove of the inner wall of the RBCC engine is similar to the "doghouse" failure phenomenon in liquid rocket engines.