Abstract:
Traditionally, the aerodynamic design of rotorcrafts relies heavily on engineering analysis methods such as lift line or vortex theory. Nowadays, however, high-performance computing makes the high-fidelity first principle simulation possible by computational fluid dynamics (CFD) methods. Based on the characteristics of rotor motions, some particular CFD methods are introduced and compared with those for fixed wings, and the shortcomings of current CFD in engineering applications are pointed out. On this basis, the development strategies and technical routines of foreign advanced helicopter CFD softwares are discussed, whose numerical methods and related technique merits are analyzed from multiple aspects including multi-solver coupling, dynamically adaptive mesh refinement, high-order schemes, turbulence models, and multi-disciplinary coupling analyses. Lastly, some suggestions on rotorcraft simulations are put forward to satisfy future needs. Due to the coupling between rotor motions and control inputs as well as structural deformations, results of CFD simulations in the way of part-by-part analyses or single-disciplinary modeling deviate from actual flight states. Therefore, future softwares of rotorcrafts should focus on multi-disciplinary coupled solutions and high resolution of rotor wakes.