Real-time simulation model for helicopter flight task analysis in turbulent atmospheric environment

Abstract

This paper presents a real-time simulation model for the analysis of the helicopter flight tasks in turbulent atmospheric environment. First, recursive algorithms are developed for independent turbulence components by discretizing the high-order turbulence filters deduced from the von Kármán model. Then, the discrete filters are related according to the spatial correlation on transverse planes. The related filters are distributed in front of a helicopter and their turbulence components are transported along the longitudinal direction of airspeed to establish a distributed turbulence model. Next, the turbulence model is integrated into a flight dynamics model, and a real-time simulation model is formed and validated against flight test data. Finally, the model accuracy and computational speed with simulation step are investigated using numerical simulations. Results show that the model computational speed increases with the increment of simulation step. However, the lower-frequency helicopter motions may be distorted by the higher-frequency turbulence disturbance when a too large simulation step was used. Following the results, appropriate simulation steps are proposed. The model accuracy and computational speed meet the real-time requirements for the helicopter flight simulations in atmospheric turbulence.