In this work, a compressible Reynolds‐averaged Navier‐Stokes code is used to investigate low Reynolds number and low Mach flows, which are typical of micro air vehicles (MAVs). The current work serves as a step toward developing a computational methodology that can serve
as a predictive tool for a variety of conventional and unconventional rotary wing MAVs. The performance of unsteady low Mach preconditioning is demonstrated using two‐dimensional inviscid isentropic vortex propagation in low Mach number flow. This is followed by extensive validation
studies on a micro hovering rotor. The effect of leading and trailing edge geometries is investigated by looking at blunt and sharp profiles and comparing with the experimental data. The thrust and power are reasonably well predicted for all the geometries. Blunt leading edge geometries show
poorer performance compared to the corresponding sharp leading edge geometries mainly because of large pressure drag acting at the blunt front. Blunt leading edge geometry also shows a significant leading edge laminar separation bubble, which results in complete separation near the tip. Sharpening
the trailing edge shows performance improvement for the blunt leading edge geometry, but not for the sharp leading edge geometry. Flow visualization shows that the tip vortex flow field is very complicated with the presence of secondary vortices and additional vortices formed due to separation
near the trailing edge. The tip vortex profiles are reasonably well predicted, but the inadequacy of the turbulence model leads to some discrepancies during tip vortex formation. The swirl velocities for the micro‐rotor is found to be significantly larger compared to full‐scale
rotor, which could be one of the reasons for additional power loss in the smaller scale rotors.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Alfred Gessow Rotorcraft Center, Department of Aerospace Engineering, University of Maryland College Park, MD
Publication date: 2010-04-01
More about this publication?
The Journal of the American Helicopter Society is the world's only scientific journal dedicated to vertical flight technology. It is a peer-reviewed technical journal published quarterly by AHS International and presents innovative papers covering the state-of-the-art in all disciplines of rotorcraft design, research and development. (Please note that AHS members receive significant discounts on articles and subscriptions.)
Journal subscribers who are AHS members log in here if you are not already logged in.
Authors can find submission guidelines and related information on the AHS website.