Physics-Based Analysis Methodology for Hub Drag Prediction

The work described in the present paper concerns the identification, application, and correlation of a physics-based analysis methodology for the prediction of hub drag on geometries of sufficient complexity and detail to represent typical modern wind tunnel tests. Bell Helicopter is currently engaged in a four-year NRTC/CRI project with one of the principal criteria for success being the identification of such a method. The results from the first two years of the project are described herein and concern applications to non-rotating hubs. Details offered include a description of the recent Bell aircraft wind tunnel test used for correlation, two different levels of complexity in the hub model, the grid generation paradigm used, the U2NCLE unstructured Navier-Stokes flow solver, several grid refinement studies conducted for the isolated fuselage and combined fuselage/hub configuration, the correlation between measured and computed data for both pitch and yaw orientations, and future work planned.