Dynamic Simulation of Flight Test Manoeuvres on the Diamond D-Jet

Abstract

The numerical simulation of the complex fluid-structure interaction taking place when manoeuvring an aircraft remains a challenge. A realistic analysis of the airplane manoeuvrability often involves the presence of moving parts, such as the deflection of the elevators, the ailerons, or the elevons. For conventional Computational Fluid Dynamics (CFD) codes, dealing with such moving geometries is a challenging task. The following work uses software based on the lattice-Boltzmann method (LBM) to overcome these issues. This paper presents a numerical study on the dynamic simulation of flight test manoeuvres on the Diamond D-JET, using the XFlow virtual wind tunnel. The pitch capture manoeuvre is first simulated, studying the pitch oscillation response of the aircraft. Dutch roll flight mode is then numerically reproduced. Finally, the D-JET angle of attack is evaluated in the poststall regime under controlled movements of the elevator. Numerical results are eventually compared with the corresponding flight test data recorded by Diamond Aircraft Industries. Numerical and experimental results show reasonable agreement. It may thus be concluded that: (i) the LBM can offer the opportunity to bypass some wind tunnel testing; and (ii) the LBM can complement flight tests by helping in mitigating risks associated with flight test manoeuvres, including fully developed stalls and spin testing.