Abstract
The noise of the main rotor of a helicopter in hover and horizontal flight modes is numerically simulated. To calculate the acoustic characteristics caused by the nonstationary load on the blades, a software package is used, validated with experimental data in hover mode. A hybrid calculation method is used, according to which the near field is calculated first, followed by the acoustic characteristics in the far field. In the near field, the values of the field parameters near the rotating blade are found by direct solution of the unsteady Euler equations in a noninertial coordinate system. To calculate the far field, the integral Ffowcs Williams–Hawkings method is applied using permeable control surfaces enclosing the blade.
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Funding
The study was partially supported by a grant from the Ministry of Science and Higher Education of the Russian Federation no. 075-11-2018-234, unique identifier RFMEFI 62718X0004.
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Vorontsov, V.I., Faranosov, G.A., Karabasov, S.A. et al. Comparison of the Noise Directivity Pattern of the Main Rotor of a Helicopter for Flight and Hover Modes. Acoust. Phys. 66, 303–312 (2020). https://doi.org/10.1134/S1063771020030082
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DOI: https://doi.org/10.1134/S1063771020030082