Terrain-correlated turbulence models for rotorcraft nap-of-the-earth flight simulations

摘要

A terrain-correlated turbulence model that is suitable for use in real-time simulations of rotorcraft nap-of-the-earth (NOE) operations has been developed and tested.The mode incorporates two key innovations that enable its use in a real-time environment:(1)the use of a 3D truncated FFT representation fo the wind and turbulence data that enables the efficient retrieval fo the terrain-corrsentation of the wind and turbulence data that enables the efficient retrieval of the terrain-correlated wind and turbulence values in real-time and (2) the use of turbulence filters to compute the fluctuating turbulence components at each rotor blade element using the terrain-correlated turbulence parameters while maintaining the spatial and temporal continuity of the turbulence.The concept was implemented by modifying NASA's GENHEL simulation fothe UH-60A Black Hawk.While the results of this study clearly indicate that the inclusion of terrain-correlated turbulence has a qualitatively and intuitively correct effect on the reponses of th erotorcraft simulation,piloted simulation evaluations are required to test the efficacy of this concept in improving simulation fidelity.