Accession Number : AD0718761

Title :   Vacuum-Air Propulsion with a Supplemental Tube Inlet.

Descriptive Note : Interim technical rept. no. 8,

Corporate Author : ARMY RESEARCH OFFICE DURHAM N C

Personal Author(s) : Chen,David ; Kumar,Sudhir ; Harman,Charles ; Buzzard,Gale

Report Date : SEP 1968

Pagination or Media Count : 110

Abstract : A study of the vacuum-air propulsion system was conducted to determine the effect of a supplemental air inlet which allows air from the atmosphere to flow into the tube as soon as the vehicle has passed that location. An experimental study was carried out on a tube 80 feet in length and 2 inches in diameter. The supplemental inlet was located at approximately 20 feet from the breech of the tube. It remains closed by a solenoid valve until the pressure of the air behind the vehicle is sensed by a transducer, which then opens the inlet. Analysis of the experimental results indicates that the effect of the supplemental inlet is to eliminate the losses from fluid friction behind the projectile in the length of tube between the breech and the supplemental inlet. This produces higher projectile velocities (n/o-15%) for other wise similar conditions. (Author)

Descriptors :   (*PASSENGER VEHICLES, *PROPULSION SYSTEMS), (*DUCT INLETS, PASSENGER VEHICLES), AERODYNAMIC CHARACTERISTICS, SKIN FRICTION, AIR, PIPES, VELOCITY, TRAJECTORIES, NUMERICAL ANALYSIS

Subject Categories : Surface Transportation and Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE