Accession Number:

ADA279680

Title:

Tipjet 80-inch Model Rotor Hover Test: Test No. 1198

Descriptive Note:

Final rept. Jan-Dec 1991

Corporate Author:

NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD SHIP SYSTEMS AND PROGRAMS DIRECTORATE

Personal Author(s):

Report Date:

1993-09-01

Pagination or Media Count:

103.0

Abstract:

An experimental investigation was conducted to examine the aerodynamic properties of a Tipjet integrated pneumatic liftreaction-drive rotor system in hover. For this rotor system, a single source of compressed air directly powers the rotor as a radial outflow turbine while simultaneously supplying the high velocity jet sheet that produces lift by means of circulation control CC along the blades. A subscale model of such a fully pneumatic Tipjet rotor system was constructed and tested on the hover test facility at the David Taylor Model Basin. The model was tested to identify unique attributes of the integrated kiftdrive system including mutual interference between tip nozzle flow and CC jet sheets and the impact of drawing CC supply air from a flowing plenum. Test results are presented for the model in four configurations 1 CC rotor with tip nozzles closed, 2 rotor locked with nozzles thrusting, 3 tip- drive CC rotor with controlled rpm, and 4 tip-jet self-drive equilibrium. The basic rotor lifting system, while exhibiting the highest augmentation ratio ever recorded for a CC rotor, suffers an induced power penalty due to the nonlifting region of the blade span where the tip nozzles are located. As expected, an internal pressure drop due to the flow rate in the blade duct was observed. There was no evidence of mutual interference effects between the lift and drive systems. Overall, the rotor exhibited a constant, linear response of lift versus pressure regardless of the slot height or the equilibrium tip speed.

Subject Categories:

  • VSTOL
  • Hydraulic and Pneumatic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE