Three-Dimensional Planing at High Froude Number
Abstract
The steady motion of a planing surface of moderate aspect ratio at small angles of attack is considered. Linearized theory is used with a square- root type of pressure singularity representing the flow near the leading edge. As asymptotic solution for the pressure distribution on the planing surface at large Froude number (or small beta, the inverse of the Froude number) is sought. The lowest order term of the pressure distribution, obtained by setting beta equal to zero, is found to be the same as the pressure distribution on the lower side of the corresponding thin wing. Higher order terms in beta are obtained by an iteration process. Explicit solutions are obtained to order beta squared for rectangular planforms. Numerical results are calculated for rectangular flat plate planing surfaces of aspect ratios from 0.5 to 2.0. It is found that for large aspect ratios the lift coefficient is reduced by the gravity effect and for small aspect ratios it is increased, the dividing aspect ratio being about 1.5. The results compare reasonably well with experimental data.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 19, 1970
- Accession Number
- AD0717067
Entities
People
- D. P. Wang
- Paul Rispin
Organizations
- The Catholic University of America