System for reducing IR visibility of an amphibious vehicle

Abstract

A system for reducing the infrar d visibility of an amphibious vehicle that generates hot exhaust gas when it is in a body of water has a nozzle directed downward at and closely juxtaposed with a surface of the body of water. This nozzle expels the hot exhaust gas downward at the surface so as to form a water-droplet cloud that cools the gas and masks the vehicle. the nozzle is set at an angle of at most 60° to vertical.

We claim:  
     
         1 . In an amphibious vehicle that generates hot exhaust gas, a system for reducing the infrared visibility of the vehicle when it is in a body of water, the system comprising 
 means including a nozzle directed downward at and closely juxtaposed with a surface of the body of water for expelling the hot exhaust gas downward at the surface so as to form a wetter-droplet cloud, whereby the cloud cools the gas and masks the vehicle.    
     
     
         2 . The system defined in  claim 1  wherein the nozzle is set at art angle of at most 60° to vertical.  
     
     
         3 . The system defined in  claim 1 , further comprising 
 means for mixing cool ambient air with the hot exhaust gas prior to expelling the hot exhaust gas from the nozzle.    
     
     
         4 . The system defined in  claim 1  wherein the mixing means includes an ejector.  
     
     
         5 . The system defin d in  claim 1  wherein the nozzle forms a restriction such that the hot exhaust gas issues from it at high speed.