Aerodynamic Analysis and Flight Simulation of an Anemometer for Rotational Stabilization of a Helicopter Slung Load

Computational fluid dynamics calculations are performed on an anemometer cup configuration in support of using the device for rotational stabilization of a slung load (CONEX) under a helicopter in forward flight. CFD calculations use delayed detached eddy simulation (DDES). Initial static calculations of a cup are performed and compared favorably with wind tunnel test data. Mach and Reynolds number effects for the slung load configuration are then quantified. Unsteady calculations of the rotating cups for a range of rotation rates are performed for comparison with the static results. Cup-cup and cup-CONEX interference on the anemometer performance are shown. A flight dynamics FLIGHTLAB simulation model of the slung load and rotational stabilizer is developed and validated against flight test data using static experimental anemometer wind tunnel data. Finally, the unsteady CFD results are employed in the FLIGHTLAB model, and differences from the static analysis are documented.