P.V.Lukianov Modeling the BVI-noise of the two-blade helicopter rotor |
Acoustic bulletin, Vol. 17 ¹ 1, (2015) |
| The paper deals with solving the problem of BVI-noise generation by a two-blade rotor. The mathematical model consists of two parts, the aerodynamical one (using the system of the Euler's equations) and the acoustical one governed by a closed system of the equations of aeroacoustics. The problem is solved with the numerical-analytical approach. The mutual influence of the noise from the advanced and departed blades is studied. The transformation of energy of longitudinal waves to that of transversal ones is revealed under certain combinations of the input parameters. The noise of the advanced blade is smooth and has significantly higher level. The noise generated by the departed blade is subjected to the strongest changes when varying the angles of attack and blade position in the rotational plane. This indicates for its vortex nature. At the same time, the rotational noise prevails for the advanced blade. Varying of the angle of attack, angle of the blade position with respect to the flow, and the Mach number quantitatively effects on the general picture of noise generation. |
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KEY WORDS: sound generation by the flow, Taylor's vortex, blade-vortex interaction, numerical-analytical methods |
| TEXT LANGUAGE: Russian |