Accession Number:

AD0737354

Title:

Preliminary Analysis of the Self-Tending Rigid Airfoils for the Hydrofoil Water Conveyance.

Descriptive Note:

Interim scientific rept.,

Corporate Author:

FRANK J SEILER RESEARCH LAB UNITED STATES AIR FORCE ACADEMY COLO

Report Date:

1971-12-01

Pagination or Media Count:

19.0

Abstract:

A theoretical analysis of the regions of stability and performance of the rigid-air-foil propulsion system for the hydrofoil sailcraft discussed in reference 1 is presented. The trailing-edge flap is either geared so as to move in proportion to the airfoil-axis or fixed at negative camber relative to the airfoil. A limited stability region in which the airfoils are self-tending is investigated using a flap-angle to airfoil-angle gear ratioK vs. distance of airfoil-mast behind the quarter chord d plot. The chordwise motion of the airfoil relative to the mast pivot is found to be essential. The stability is found to be better and overall aerodynamic performance is enhanced for higher apparent winds. Aside from the ability to point higher into the apparent wind due to a larger lift-to-drag ratio, best overall craft performance is obtained on a beam reach. The broadest range of wind angles, for which the craft is self-tending, is obtained for a fixed positive flap angle actually, a negative camber is thereby implied. Author

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE