Accession Number:

AD0773026

Title:

Analytical Investigation of the Aerodynamic Stability of Helical Vortices Shed from a Hovering Rotor

Descriptive Note:

Final rept.

Corporate Author:

ROCHESTER UNIV NY

Personal Author(s):

• Gupta, Bharat P.
• Loewy, Robert G.

Report Date:

1973-10-01

Pagination or Media Count:

150.0

Abstract:

A small-perturbation stability analysis of a doubly infinite array of interdigitated, right circular helical vortices has been formulated. This array corresponds to the vortices trailed from the tips of the blades of a helicopter rotor or propeller in static thrust or axial flight condition and at great distance from the plane of rotation of the blades. The analysis makes use of the Biot-Savart law of induction and the Vorticity Transport Theorem. The singularities in the Biot-Savart integration for self-induction have been eliminated by substituting approximate functions. Near-singular behavior in other integrals has been minimized by adding and subtracting functions with similar near-singular behavior and which have exact, closed-form integrals.

Descriptors:

• *HELICOPTER ROTORS
• *VORTEX SHEDDING
• AERODYNAMIC STABILITY
• DIGITAL SIMULATION
• FLOW FIELDS
• PERTURBATIONS
• VORTICES
• WAKE

Subject Categories:

• Aerodynamics
• Helicopters

Distribution Statement:

APPROVED FOR PUBLIC RELEASE