An Experimental Study of the Ventilation of Blunt-Based Surface-Piercing Struts
Abstract
An experimental program was conducted in the Lockheed Underwater Missile Facility to investigate the ventilation characteristics for surface-piercing blunt-based struts in calm water and in waves. Struts with two leading-edge configurations, one sharp and one blunt, were tested, and the ventilation characteristics are compared with those previously obtained for struts with streamlined trailing edges to determine the effects of the blunt base. The experiments were performed at low ambient pressures to obtain ventilation inception under simultaneous Froude and cavitation number scaled conditions. Performance comparisons are made at strut yaw angles of six and eight degrees on the bases of resistance to ventilation and of the effects on hydrodynamic forces when ventilation occurs. The blunt-based struts are found to be more subject to ventilation than the streamlined struts. Of the blunt-based struts, ventilation resistance is best for a configuration combining a blunt leading edge with sides contoured to a maximum strut thickness at the base. With respect to hydrodynamic forces, the blunt-based struts are considerably better than the streamlined configurations. The side forces are higher before ventilation and do not decrease as much (and remain in the same direction) after ventilation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1972
- Accession Number
- AD0759046
Entities
People
- Ray L. Kramer
Organizations
- Lockheed Martin Missiles and Space