Prediction of Helicopter Rotor Downwash in Hover and Vertical Flight

reportActive / Technical Report | Accession Number: ADA074154 | Open PDF

Abstract:

A method is presented for the calculation of rotor downwash in hovering and vertical flight. The blade is represented by a lifting line. The rotor wake is simulated by a vortex sheet and a series of rolled-up root and tip vortices, similar in form to that of a classical fixed-wing. The concept of rectangularization of the rotor wake is used in obtaining a formula for the normal component of induced velocity. Wake contraction based on experimental data is introduced into the calculations. Numerical calculations have been performed for two rotor configurations, viz. S.58, and a model rotor. Computed induced velocities and blade loadings are compared with the available flight data. The comparison shows the present simple method yields satisfactory results.

Author(s):
Reddy, K. R.
Author Organization(s):
AERONAUTICAL RESEARCH LABS MELBOURNE (AUSTRALIA)
Descriptive Note:
Aerodynamics rept.
Pagination:
0036

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
ARL-AERO-150, ARL/MEL-AR-001-335
Monitor Series:
AR-001-335, ARL/MEL
 Subject Terms
Joint Capability Areas:
JCA_1_Force Support; JCA_4.6_Engineering; JCA_1.2_Force Preparation; JCA_5_Command and Control; JCA_5.3_Planning; JCA_1.2.3_Educating; JCA_1.2.6_Concepts
Communities of Interest:
Air Platforms
Descriptor(s):
*DOWNWASH, *ROTOR BLADES(ROTARY WINGS), AUSTRALIA, HOVERING, MATHEMATICAL PREDICTION, SUBSONIC FLIGHT, VERTICAL ORIENTATION, VORTICES, WAKE
Field(s)/Group(s):
Aircraft, Fluid Mechanics
Keyword(s):
VERTICAL FLIGHT, S 58 AIRCRAFT, FOREIGN REPORTS
Report Date:
1979 Jan 01