Academic
Publications
GENERALIZED VISCOUS VORTEX MODEL FOR APPLICATION TO FREE-VORTEX WAKE AND AEROACOUSTIC CALCULATIONS

GENERALIZED VISCOUS VORTEX MODEL FOR APPLICATION TO FREE-VORTEX WAKE AND AEROACOUSTIC CALCULATIONS,Mahendra J. Bhagwat,J. Gordon Leishman

GENERALIZED VISCOUS VORTEX MODEL FOR APPLICATION TO FREE-VORTEX WAKE AND AEROACOUSTIC CALCULATIONS   (Citations: 3)
BibTex | RIS | RefWorks Download
The development of a generalized viscous vortex model is described for application in rotor aeroacoustic analyses. A brief summary is given of previous models for the viscous core growth and induced velocity field of a trailing tip vor- tex. The assumptions made for the vortex core growth are shown to influence the predictions of the rotor wake ge- ometry, as well as the induced velocities, airloads, and performance, thereby emphasizing the need for a more universal and physically representative vortex model. In the present approach, the viscous core growth was mod- eled using an extension of the classic Lamb-Oseen model for the diffusion of laminar vortices. Turbulence in the tip vortex affects the diffusion of vorticity, and these effects were incorporated using an empirically validated correc- tion for the average apparent or "eddy" viscosity. The vortex induced velocity profiles measured in experiments were found to exhibit strong self-similarity when using the vortex core radius as a length-scale, suggesting that a gen- eralized model is possible. A family of algebraic models for the swirl, axial, and radial components of the veloc- ity induced by a viscous trailing tip vortex is proposed. These velocity components were found from a solution to a simplified form of the incompressible Navier-Stokes equations. The velocity profiles are written in terms of a single integer exponent with the viscous core growth be- ing given by a semi-empirical relation for the turbulent viscosity that scales as a function of the vortex Reynolds number. The model is compared with velocity field mea- surements for both fixed-wing and rotating-wing tip vor- tices, with good agreement.
Published in 2002.
Cumulative Annual
View Publication
The following links allow you to view full publications. These links are maintained by other sources not affiliated with Microsoft Academic Search.
Sort by: