Flight vehicle with integral guidance sensor window and cavitator for controlled underwater trajectory

Abstract

A flight vehicle configured for underwater trajectory includes a vehicle forebody attached to a fuselage. The flight vehicle forebody has a curved sensor window and an integral ring cavitator situated aft of the sensor window that triggers and manages cavitation underwater during the underwater trajectory. The placement of the integral ring cavitator aft of the curved sensor window provides the sensors with a forward field of view enabling guidance. The curved sensor window and the integral ring cavitator may be configured to transfer load at impact with water to the fuselage. The size and the shape of the of the integral ring cavitator, the location of the integral ring cavitator with respect to the forebody, and the shape of the curved sensor window are selected to generate a cavitation bubble and maintain a pitch angle when the flight vehicle is traveling underwater.

What is claimed is: 
     
         1 . A flight vehicle configured for underwater trajectory, the flight vehicle comprising: 
 a fuselage; and   a flight vehicle forebody attached to the fuselage, the flight vehicle forebody comprising: 
 a curved sensor window; and 
 an integral ring cavitator situated aft of the sensor window, 
 wherein the integral ring cavitator is configured to trigger and manage cavitation underwater during the underwater trajectory. 
   
     
     
         2 . The flight vehicle of  claim 1 , wherein the curved sensor window and the integral ring cavitator are configured to transfer load at impact with water to the fuselage.  
     
     
         3 . The flight vehicle of  claim 2 , wherein the integral ring cavitator comprises one or more full or partial rings.  
     
     
         4 . The flight vehicle of  claim 3 , wherein each of the one or more full or partial rings comprises a substantially flat surface that is angled at 90 degrees or more with respect to a y-axis of the flight vehicle.  
     
     
         5 . The flight vehicle of  claim 4 , wherein a size and a shape of the of the integral ring cavitator, a location of the integral ring cavitator with respect to the forebody, and a shape of the curved sensor window are selected to generate a cavitation bubble when the flight vehicle is traveling underwater. 
     
     
         6 . The flight vehicle of  claim 5 , wherein the size and the shape of the of the integral ring cavitator, the location of the integral ring cavitator with respect to the forebody, and the shape of the curved sensor window are further selected to cause supercavitation when the flight vehicle is traveling underwater.  
     
     
         7 . The flight vehicle of  claim 5 , further comprising gas injectors provided behind the integral ring cavitator to augment the cavitation bubble when the flight vehicle is traveling underwater.  
     
     
         8 . The flight vehicle of  claim 5 , wherein the size and the shape of the of the integral ring cavitator, the location of the integral ring cavitator with respect to the forebody, and the shape of the curved sensor window are further selected to maintain a pitch angle of the underwater trajectory when the flight vehicle is traveling underwater within the cavitation bubble.  
     
     
         9 . The flight vehicle of  claim 5 , wherein a shape of the forebody is configured to control the underwater trajectory 
     
     
         10 . The flight vehicle of  claim 5 , wherein the integral ring cavitator comprises a single ring with a substantially flat surface that is angled up to degrees with respect to the y-axis of the flight vehicle, and 
       wherein the integral ring cavitator has a height that extends no greater than a maximum diameter of the forebody at the fuselage. 
     
     
         11 . The flight vehicle of  claim 5 , wherein the curved sensor window comprises an optically transparent material and is configured to house one or more optical sensors configured for optical guidance. 
     
     
         12 . The flight vehicle of  claim 11 , wherein the curved sensor window comprises one of Sapphire, Aluminum oxynitride, Borosilicate glass, and a glass ceramic material. 
     
     
         13 . The flight vehicle of  claim 12 , wherein the curved sensor window comprises a dome having a hemispherical surface. 
     
     
         14 . The flight vehicle of  claim 1 , wherein the flight vehicle is an airflight diving vehicle having an initial portion of its trajectory in air and a subsequent portion of its trajectory underwater.  
     
     
         15 . A flight vehicle forebody configured for attachment to a fuselage of a flight vehicle, the flight vehicle forebody comprising: 
 a curved sensor window; and   an integral ring cavitator situated aft of the sensor window,   wherein the integral ring cavitator is configured to trigger and manage cavitation underwater during underwater trajectory of the flight vehicle.   
     
     
         16 . The flight vehicle forebody of  claim 15 , wherein the integral ring cavitator comprises one or more full or partial rings, each of the one or more full or partial rings comprises a substantially flat surface that is angled at 90 degrees or more with respect to a y-axis of the flight vehicle. 
     
     
         17 . The flight vehicle forebody of  claim 16 , wherein a size and a shape of the of the integral ring cavitator, a location of the integral ring cavitator with respect to the forebody, and a shape of the curved sensor window are selected to generate a cavitation bubble when the flight vehicle is traveling underwater. 
     
     
         18 . A method for controlling underwater trajectory of a flight vehicle during underwater travel, the method comprising: 
 triggering and managing cavitation underwater during underwater trajectory of the flight vehicle with an integral ring cavitator aft of a curved sensor window, the integral ring cavitator and the curved sensor window being an integral part of a flight vehicle forebody.   
     
     
         19 . The method of  claim 18 , further comprising transferring load at impact with water to a fuselage with the curved sensor window and the integral ring cavitator, the fuselage being coupled to the forebody.  
     
     
         20 . The method of  claim 19 , further comprising generating a cavitation bubble when the flight vehicle is traveling underwater, the cavitation bubble generated based on a size and a shape of the of the integral ring cavitator, a location of the integral ring cavitator with respect to the forebody, and a shape of the curved sensor window.