Comparison of Experimental and CFD Results for RAIDER X® Competitive Prototype 1/9th Scale Model

Computational Fluid Dynamics (CFD) analyses are compared with 1/9th model-scale wind-tunnel test measurements for the RAIDER X® Competitive Prototype (CP). A multitude of comparisons with experiment are made, including measured airframe aerodynamic forces and moments, surface pressures, propulsor performance and propulsor-airframe interactions, surface flow visualization, and flow field velocimetry. The CFD tools STAR-CCM+ and CREATE-AVTM Helios were both utilized to simulate the test conditions. The CFD analyses, both using the Spalart-Allmaras turbulence model, yielded results which showed good trending with the experimental data. Overall, the CFD tools demonstrated their ability to accurately analyze the behavior of flow over a complex geometry at a variety of orientations. At the same time, a few areas of improvement were identified, such as in regimes of flow separation and complex airflow interactions (such as the hubs' wake impacting the tail). In these areas, trends are often captured, but further investigation and refinements in the CFD analyses are warranted to improve correlations with the experimental data.