| Author | Mustafa Dindar, Andrew Lemnios, Mark S. Shephard, Kenneth Jansen and David Kenwright |
|---|---|
| Title | Effect of Tip Vortex Resolution on UH-60A Rotor-Blade Hover Performance Calculations |
| Year | 1998 |
| Pages | 45-57 |
| Editor | - - |
| Abstract | The effect of tip vortex resolution on the hover performance of the UH-60A rotor blade is investigated numerically. For this purpose, an adaptive refinement procedure is developed for computing vortical flows encountered in rotor aerodynamics. A two-level adaptation procedure based on interpolation error estimate and a novel vortex core detection technique is used to resolve the flow-field of rotor blades in hover. For the UH-60A rotor blade, a zero thrust case is analyzed initially because the flow-field conditions for this case are less severe compared to higher thrust cases of the same rotor blade. The effect of tip vortex for the zero thrust UH-60A computations is not strong. However for this case, another bound vortex in strong interaction with the blade is identified at 75% radius and it is believed that this vortex tube exists due to an abrupt differential change in thrust loading. As a second case, a high-thrust hover condition for the UH-60A rotor blade is analyzed. For this high-thrust case, the tip vortex interaction is strong and has to be computed as accurately as possible to get good agreement between computed and measured performance characteristics of the UH-60A blade. |