Expedited aeroelastic analysis using proper orthogonal decomposition and reduced order modelling

As modern aircraft aims for improved aerodynamic efficiency, thin wings are introduced in order to reduce its drag. As wings tend to become more flexible and thinner, it will cause more possibility of failure and aeroelastic instabilities. Therefore it requires precise stability analysis. Relevant aerodynamic analysis can be performed by both two-dimensional linearized potential theory, especially doublet lattice method (DLM) and three-dimensional computational fluid dynamics (CFD). For flutter analysis, traditional DLM is used as it is efficient in terms of computational cost and benign reliability. In this paper, an in-house flutter analysis using DLM is established. It is verified by comparison with the existing commercial program, ZAERO, and wind tunnel experiments. Also, CFD with proper orthogonal decomposition-reduced order modelling (POD-ROM) is developed. POD-ROM is used to reduce computational resources significantly which is one of the biggest drawbacks of CFD. When coupled with CFD, it will be capable of accurately analyzing aeroelastic behavior of aircraft while keeping computational cost affordable. By a few verification cases for incompressible flow and structures with large deflection, the current POD-ROM is proved to be reliable.