Is CSSO/RSA method better than single-level MDO method in design of cruise missile

Concurrent Subspace Optimization (CSSO) method performs better than single-level Multidisciplinary Design Optimization (MDO) method in some test problems, but these test problems are not complex enough. Our aim is to see whether or not CSSO/RSA, a special form of CSSO based on RSA (Response Surface Approximation) performs better in the design of integral rocket-ramjet cruise missile. In the full paper, we explain in much detail how to use CSSO/RSA to design integral rocket-ramjet cruise missile; here we give only a briefing. CSSO/RSA utilizes some parameters obtained from RSA model and can exploit the optimization capabilities of disciplines to improve the system level optimization result. Discipline optimization processes, which can be executed concurrently, avoid multidisciplinary analysis which cost most of computational time during MDO process. So, compared to single-level method, CSSO/ RSA method can improve the design optimization result and reduce computation time. We obtained design optimization results with both CSSO/RSA method and single-level MDO method. For CSSO/RSA method, the improvement in design optimization was 4.34% and the computation time was 1.25 h; for single-level MDO method, the improvement in design optimization was 3.47% and the computation time was 1.50 h. These results show preliminarily that CSSO/RSA method is better than single-level MDO method in the design of integral rocket-ramjet cruise missile.