NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Induced Power of the Helicopter RotorA simplified rotor model was used to explore fundamental behavior of lifting rotor induced power at moderate and high advance ratios. Several rotor inflow theories, including dynamic inflow theory and prescribed-wake vortex theory, together with idealized notional airfoil stall models were employed. A number of unusual results were encountered at high advance ratios including trim control reversal and multiple trim solutions. Significant increases in rotor induced power (torque) above the ideal minimum were observed for moderately high advance ratio. Very high induced power was observed near and above unity advance ratio. The results were sensitive to the stall characteristics of the airfoil models used. An equivalent wing analysis was developed to determine induced power from Prandtl lifting line theory and help interpret the rotor induced power behavior in terms of the spanwise airload distribution. The equivalent wing approach was successful in capturing the principal variations of induced power for different configurations and operating conditions. The effects blade root cutout were found to have a significant effect on rotor trim and induced power at high advance ratios.
Document ID
20050156643
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Ormiston, Robert A.
(Army Aviation Systems Command Moffett Field, CA, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2004
Subject Category
Aircraft Propulsion And Power
Meeting Information
Meeting: American Helicopter Society 60th Annual Forum and Technology Display
Location: Baltimore, MD
Country: United States
Start Date: June 8, 2004
End Date: June 10, 2004
Sponsors: American Helicopter Society, Inc.
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available