UNICADO: multidisciplinary analysis in conceptual aircraft design

Abstract

AbstractIn this paper, different iterative methods, so-called architectures, within the multidisciplinary analysis in conceptual aircraft design of the UNICADO software are elaborated, applied and analyzed. Possible execution sequences in the sequential method (Gauss-Seidel architecture) are derived via a graph-based algorithm in combination with expert knowledge. Sensitivities of the design disciplines are analyzed and a permitted residual for stable convergence characteristic for the aircraft design with UNICADO is derived. Prerequisites for the application of a parallel iterative method, the Jacobi architecture are conducted. Runtime and convergence characteristics of the Gauss-Seidel architecture and the Jacobi architecture are evaluated. A damping method is applied to the Jacobi architecture to enhance the convergence characteristics. The Gauss-Seidel and Jacobi architectures are used to design two different aircraft, the CSR and the CSMR, with an iteration accuracy of 2.5e–3. For these use cases studied, the Gauss-Seidel architecture converges more stably and faster than the Jacobi architecture and is, therefore, the more favorable. The aircraft design with the implemented Jacobi architecture oscillates and does not converge. Only with an implemented damping method, convergence is achieved. If the iteration time of the design loop increases, e.g., when using higher fidelity methods for aircraft design, the choice of architecture must be re-evaluated.