P.V.Lukianov Unsteady propagation of small disturbances from a thin wing: The near and far field |
Acoustic bulletin, Vol. 12 ¹ 3, (2009) |
| Under certain limitations, an equation of small disturbances propagation in a three-dimensional unsteady flow around a thin wing has been derived. In a linear approximation, it has been shown to coincide with the known equation of acoustics of a moving heterogeneous medium. Frequency analysis of various cases of equation simplification has been carried out. Using the the generalized Green's formula and Kirchoff's approach, an integral relation has been obtained for interconnecting of the near and far field. A comparative analysis of the through solution with existing approaches is given. A numerical example is offered for computation of the near and far sound fields generated at interaction of helicopter's rotor blade with a nonuniform flow. |
|
KEY WORDS: flow around a rotor blade, aeroacoustcs, sound generation by flow, Kirchoff's approach, Green's formula, near and far field |
| TEXT LANGUAGE: Russian |