Venting apparatus for controlling missile underwater trajectory

DETAILED DESCRIPTION Accordingly, the present invention relates to apparatus for actively controlling the venting of gas from the interior of a missile in such a manner as to influence the trajectory of the missile during the course of underwater travel.
When a missile is ejected from a submarine launch tube, gas vents from cavities within the interior of the missile through openings in the missile structure out into the water as the missile travels from deep water to the surface (as a consequence of the gas expanding due to the decreasing surrounding water pressure).
Typically this gas venting is studied and its effect on missile motion is analyzed during underwater testing for possible harmful effects; this invention utilizes the venting gases for controlled beneficial effects.
While a missile is traveling underwater, the pressure that the water exerts on the exterior surface of the missile varies over the path from the nose tip to the bottom end of the cylindrical main body.
Where the water flows in a path that is concave adjacent to the missile surface (such as at a point mid-way between the tip of the nose and the junction between the nose and the cylindrical body), there will exist a lower localized pressure than in a region where the flow is straight (such as along the cylindrical body sides) or convex (such as near the tip of the nose).
The present invention exploits this naturally occurring non-uniform pressure distribution by directing venting gas into selected regions that would otherwise be at low pressure, hence altering the pressure distribution over a portion of the surface of the missile so as to influence the trajectory of the missile.
The vented gas produces a layer of gas extending down the length of the missile.
This layer permits the higher pressure near the aft end of the cylindrical portion of the body to be transmitted upward to the lower pressure region of the nose.
It should be clearly understood and emphasized that this technique of altering the water pressure distribution by admitting vented gas into the flow of water in what would otherwise be local regions of low pressure is materially different than using the reaction forces of gas jets to control missile attitude