Aeroacoustic Simulation of a Complete H145 Helicopter in Descent Flight

作者：Kowarsch Ulrich^*; Oehrle Constantin; Kessler Manuel; Kraemer Ewald

来源：Journal of the American Helicopter Society, 2016, 61(4): 042001.

DOI：10.4050/JAHS.61.042001

In recent years, the aeroacoustic noise emission of a helicopter has become an important and challenging issue in helicopter development. Blade-vortex interaction in descent flight is one of the dominant phenomena characterizing the helicopter's aeroacoustic footprint, which is insufficiently predicted by low-fidelity computational methods. For high-fidelity noise prediction of a helicopter configuration, a multidisciplinary computational fluid dynamics-computational structure dynamics-computational aeroacoustics (CFD-CSD-CAA) tool chain has been established at the Institute of Aerodynamics and Gas Dynamics of the University of Stuttgart. With higher order CFD-based noise generation at the near field and the noise convection using a FfowcsWilliams-Hawkings based CAA code, very good agreement with measured aeroacoustic noise in a wind tunnel as well as free flight experiments of helicopters is achieved. Past simulations had been limited to the main rotor's geometry, where some residual deviations to the experiments still existed. We present a high-fidelity aeroacoustic simulation of a complete helicopter configuration and the benefits compared to an isolated rotor simulation in predicting its aerodynamic noise emission. Shading and reflection effects are clearly resolved, influencing the behavior of the helicopter's noise radiation. The simulated aeroacoustic noise emission of the helicopter lies within the experimental variation and therefore shows highly promising results for the next generation of aeroacoustic noise predictions.

• 出版日期2016-10