Accession Number:

AD1004039

Title:

Measurements to Understand the Flow Mechanisms Contributing to Tandem Rotor Outwash

Descriptive Note:

Conference Paper

Corporate Author:

US Army Aviation Development Directorate Moffett Field United States

Personal Author(s):

• Ramasamy,Manikandan
• Potsdam,Mark
• Yamauchi,Gloria K.

Report Date:

2015-05-23

Pagination or Media Count:

36.0

Abstract:

Downwash and outwash characteristics of a model-scale tandem-rotor system in the presence of the ground were analyzed by identifying and understanding the physical mechanisms contributing to the observed flow field behavior. A building block approach was followed in simplifying the problem, separating the effects of the fuselage, effects of one rotor on the other, etc. Flow field velocities were acquired in a vertical plane at four aircraft azimuths of a small-scale tandem rotor system using the particle image velocimetry PIV technique for radial distances up to 4 times the rotor diameter. Results were compared against full-scale CH-47D measurements.

Descriptors:

• Rotary wing aircraft
• downwash
• High velocity
• Flow visualization
• Helicopter rotors
• VERTICAL TAKEOFF AIRCRAFT
• helicopters
• whiteout
• hovering
• scale models

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE