| 摘要 |
A porous barrel, projectile passageway, or tube as a type of supersonic nozzle for projectile propulsion therein and method for optimizing projectile velocity therethrough. The porous barrel features a barrel wall containing holes, passageways, or otherwise porous material through the barrel wall that allows gas, fluid, or other matter to exit or move in a direction away from the barrel interior. The flow of gas, fluid, or other matter away from the barrel interior allows gas within the barrel to expand in a direction transverse to the projectile path. The amount of transverse expansion of the gas in the barrel interior can be controlled by the porosity of the barrel wall to cause any desired amount of gas expansion. Transverse expansion allows axial gas velocities within the barrel to exceed the local speed of sound as if the gas had passed through a converging diverging nozzle. In one embodiment, a pressurized gas source supplies a pressure propelling the projectile through a gun barrel, and gas outflow from passageways through the barrel wall allows gas within the barrel, as well as the projectile, to obtain supersonic velocities as the gas and projectile accelerate. |
