Skip to main content

A Variational Method for Computing the Optimal Aerodynamic Performance of Conventional and Compound Helicopters

Buy Article:

$30.00 plus tax (Refund Policy)

Abstract:

We present a variational method for computing the optimal aerodynamic performance of conventional and compound helicopters in trimmed flight. The optimal circulation distribution minimizes the sum of the induced and viscous power required to develop a prescribed lift and/or thrust, subject to any constraints that the helicopter be trimmed in pitch and roll. The minimum total power circulation distribution problem is cast as a variational problem, which in turn is solved efficiently using a vortex‐lattice technique. Included in the analysis is the viscous profile power,which is estimated at each airfoil section using an experimental or numerically computed drag polar. The resulting analysis—which is the viscous helicopter analogue of Goldstein's inviscid propeller theory—gives rigorous upper bounds on the performance of conventional and compound helicopters and may be used to predict the rotor/wing loadings that produce optimal performance. We show that helicopters with either coaxial rotors or a wing and rotor in combination can substantially reduce power loss by producing a more efficient wake structure and by reducing the induced power associated with roll trim.

Document Type: Research Article

DOI: http://dx.doi.org/10.4050/JAHS.55.042006

Affiliations: Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC

Publication date: October 1, 2010

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.

ahs/jahs/2010/00000055/00000004/art00006
dcterms_title,dcterms_description,pub_keyword
6
5
20
40
5

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more