CFD Simulation of Flow Around ROBIN-Mod7 Fuselage with PSP Rotor Using an Immersed Boundary Method

Abstract

Computational fluid dynamics simulations of the flow around the ROBIN-mod7 fuselage with PSP rotor are conducted using an immersed boundary method and an actuator surface model in OpenFOAM. The ROBIN-mod7 fuselage is represented by the immersed boundary method, while the unsteady rotor is modeled using the actuator surface model. The integration of the immersed boundary method and actuator surface model is straightforward; there is no fundamental reason to be conflicted with each other in both theory and practice. A comprehensive analysis of the generic helicopter configuration is carried out for the hovering flight condition; the isolated fuselage is simulated to provide its baseline aerodynamics, and the isolated rotor and rotor-fuselage cases are studied to measure the rotor performance in hover and the fuselage effect on the performance. The validation of each test case is conducted against both experimental measurements and computational data from the literature. The surface pressure data from the isolated fuselage case shows good agreement with the experimental measurements. Also, the rotor performance predicted on the isolated and installed rotors (rotor-fuselage) has excellent agreement with the reference data; in particular, the performance data on the installed rotor agrees with the experimental data better than the previous numerical study does. The fuselage effect has been analyzed by comparing the isolated rotor and rotor-fuselage data sets. The computational effort for different grid levels of each test case is provided. Overall, the results have demonstrated an equivalent level of accuracy compared to the previous high-fidelity simulation results at their fraction of setup and computational expenses.