Accession Number:

ADA224238

Title:

Numerical Simulations of Blade-Vortex Interactions and Lifting Hovering Rotor Flows

Descriptive Note:

Final technical rept. Feb 1988-Feb 1990

Corporate Author:

JAI ASSOCIATES INC MOUNTAIN VIEW CA

Personal Author(s):

Report Date:

1990-04-01

Pagination or Media Count:

72.0

Abstract:

This report presents viscous, three-dimensional numerical solutions of two related problems of a helicopter rotor. An implicit, finite-difference numerical procedure is used for the solution of the thin layer Navier-Stokes equations to simulate the flowfield solutions of 1 helicopter rotor blade encountering a passing concentrated line vortex, and 2 a lifting hovering rotor, at both sub- and super-critical flowfield conditions. For the first problem, the Euler equations were also solved independently to assess the importance of the viscous effects in the interacting flowfield. A prescribed vortex method is adopted to preserve the structure of the interacting vortex. Both parallel and oblique blade-vortex interactions have been calculated. The second problem considered is that of calculating lifting hovering rotor flowfields without using any ad hoc wake models. The induced effects of the wake, including the interaction of tip vortices with successive blades, are captured as a part of the overall flowfield solution and hence no wake models are used. In order to preserve the structure of the vortex wake, a completely upwind finite-difference numerical procedure is used for this problem. Comparison of the numerical results show excellent agreement with the experimental data and with the previously published Navier-Stokes calculations that used a simple wake model.

Subject Categories:

  • Aerodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE