An Application of the Flow360 Solver to the Hover Download Prediction Problem

This paper presents the contribution of Flexcompute to the Hover Prediction Workshop, with a focus on hover performance and download predictions. The analysis is focused on HVAB rotor blade simulations at two blade tip Mach numbers of 0.58 and 0.65. First, a rigorous mesh refinement and time step study is performed to assess the discretization error sensitivities for both isolated and installed rotors. The impact of mesh resolution and time step on the performance, sectional loading and flow features is presented with recommendations put forward for engineering level accuracy and high-fidelity solutions. An analysis of loads convergence is also performed, which was found to affect the predictions for installed rotor calculations. Next, a collective sweep study is performed at two blade tip Mach numbers for isolated and installed rotors, and where available comparisons are made with experimental data and predictions from other CFD codes. The Flow360 results showed strong correlation with reference data and resolved high-resolution wake structures, showing the applicability of Flow360 to hovering rotor solutions.