REDUCTION IN DRAG OF SUBMERGED BODIES BY PARTIAL ENCLOSURE IN GASEOUS CAVITIES
Abstract
The cavity-travel technique, in which gas is in jected at the vehicle, is a feasible method of reducing the net drag of a submerged body rela tive to that of a fully-wetted body. The net drag reduction is largest for short high-speed vehicles (e.g., 8-18% for a 20-ft vehicle at 100 kt) and becomes negligibly small for vehicles longer than approximately 100 ft. Drag reduc tions can be achieved with cavity-travel vehicles in which the gas-recovery and recirculation sys tems are eliminated. The gas consumption rate (i.e., the rate at which gas is lost oberboard) for this mode of operation is approximately the same as that of a vehicle which employs gas re covery. Although present data indicate a drag advantage for vehicles with gas recovery, the greater simplicity of vehicles without recovery may make vehicles of this type more attractive for particular applications. The performance of gas recovery systems employed for cavity closure is limited primarily by the effects of instabi lities of the gas-water interface. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 10, 1963
- Accession Number
- AD0340908
Entities
People
- John W. Reece
- William F. Perkins
Organizations
- United Technologies Corporation