Accession Number:

AD0809185

Title:

AN ANALYTICAL METHOD OF DETERMINING GENERAL DOWNWASH FLOW FIELD PARAMETERS FOR V/STOL AIRCRAFT

Descriptive Note:

Technical rept. Apr-Aug 1966

Corporate Author:

AIR FORCE AERO PROPULSION LAB WRIGHT-PATTERSON AFB OH

Personal Author(s):

• Hohler, David J.

Report Date:

1966-11-01

Pagination or Media Count:

75.0

Abstract:

This report presents a method of analytically determining the general downwash flow field parameters of various types of VSTOL aircraft. The basic difference between the operation of VSTOL aircraft and conventional aircraft is their method of take-off and landing. During these operations, VSTOL aircraft produce high downwash air velocities that impinge and spread out over the surface of the ground. Depending on the size, type, and number of engines on the aircraft, this downwash can cause damage to nearby aircraft, equipment, or personnel. Past theoretical methods based on incompressible flow theory have been unsuccessful in establishing a means of computing this downwash flow field. A combined method, however, of proven experimental data and certain analytical approaches have yielded a useful means of predicting the general downwash flow field parameters. This report presents these approaches and demonstrates their usefulness.

Descriptors:

• *VERTICAL TAKEOFF AIRCRAFT
• *SHORT TAKEOFF AIRCRAFT
• VELOCITY
• EXPERIMENTAL DATA
• HAZARDS
• PERFORMANCE(ENGINEERING)
• TERRAIN
• FLOW FIELDS
• MATHEMATICAL PREDICTION
• MATHEMATICAL ANALYSIS
• PRESSURE
• GRAPHICS
• EQUATIONS
• DOWNWASH
• EXHAUST GASES

Subject Categories:

• VSTOL
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE