Aerodynamic Analysis of Rotor Blades using Overset Grid with Parallel Computation

Abstract

The helicopter aerodynamics is simulated in hovering and forwarding flight using the unsteady Euler equations. As the steady condition, flight test of DLR-F6 and hovering flight test data of Caradonna & Tung’s rotor blades were used, and as the unsteady condition, non-lift forwarding flight test data of the rotor blades were used. The parallelized numerical solver was validated with the two of data above. By using this solver, AH-1G rotor blades to forwarding flight numerical test were conducted. In the test of forwarding flight, the numerical trim was applied to decide cyclic pitching angles using the Newton-Raphson method, and the results were good well match to the experimental data, Especially, the BVI effects were well simulated in advancing side in comparison with other numerical results. To consider the blade motion and moving effects, an overset grid technique is applied and for the boundary, Riemann invariants condition is used for inflow and outflow.