Efficient Aeroelastic Solution Based on Time-Spectral Fluid–Structure Interaction Method

Abstract

Although the traditional transonic aeroelastic numerical analysis in the time domain is accurate, the high computational cost limits its application. Therefore, in this Paper, an efficient aeroelastic numerical solution based on the time-spectral method, called the time-spectral fluid–structure interaction method, is developed. The periodic aerodynamic forces and structure equations are calculated by using the time-spectral method and the double-iteration method, respectively. The novelty of this method is that in the inner iteration the variable with a strong coupling effect is solved by using the gradient method and the remaining variables are then solved by using the least-square method. Moreover, the computational fluid dynamics solver is not required in the inner iteration. By using the double-iteration method, not only does the computational cost decrease, but the stagnation of the convergence, which occurs frequently when using the one-shot method to search for the critical point, can be avoided. The two-dimensional aeroelastic standard test cases are then used to validate this method. Results show that the flutter boundary and the critical characteristics of the limit cycle oscillation can be captured with a few iterations by the time-spectral fluid–structure interaction method, and the results of this method agree well with those of the traditional time-domain method. This method can improved by one to two orders of magnitude in computational efficiency with a good robustness to initial conditions.