Thrust vectoring shroud for fluid dynamic device

Abstract

A fluid dynamic device including a shroud disposed about a central axis and having an upstream fluid intake region and a downstream fluid exit region, the shroud directing fluid flow between the upstream fluid intake region and the downstream fluid exit region. The shroud is configured so that, at least during some operating conditions of the fluid dynamic device, at least a portion of fluid exiting the fluid exit region is directed towards the central axis.

1 . A fluid dynamic device, comprising:
 a shroud disposed about a central axis and having an upstream fluid intake region and a downstream fluid exit region, the shroud directing fluid flow between said upstream fluid intake region and said downstream fluid exit region wherein the shroud is configured so that, at least during some operating conditions of the fluid dynamic device, at least a portion of fluid exiting the fluid exit region is directed towards the central axis.   
   
   
       2 . The fluid dynamic device of  claim 1 , wherein said device is an airborne craft and the fluid is air. 
   
   
       3 . The fluid dynamic device of  claim 2 , wherein said shroud redirects air from the fluid intake region to a generally downward direction to create a lifting thrust for the airborne craft. 
   
   
       4 . The fluid dynamic device of  claim 3 , wherein said shroud is disposed about said central axis, said axis being in the same direction as the thrust generated by the airborne craft. 
   
   
       5 . The fluid dynamic device of  claim 1 , wherein the shroud has a neutral position in which predominately all of the fluid exiting the fluid exit region of the shroud is directed towards said central axis. 
   
   
       6 . The fluid dynamic device of  claim 1 , wherein the fluid intake region causes fluid to enter the shroud in a direction parallel to the axis of the shroud. 
   
   
       7 . The fluid dynamic device of  claim 1 , wherein the fluid intake region causes fluid to enter the shroud in a radial direction. 
   
   
       8 . The fluid dynamic device of  claim 1 , wherein the fluid intake region is in the form of an annular ring. 
   
   
       9 . The fluid dynamic device of  claim 1 , wherein the angle of fluid exiting the fluid exit region is between 45 and 135 degrees to the central axis. 
   
   
       10 . The fluid dynamic device of  claim 1 , further comprising:
 at least one drum rotor fan having a rotor for generating radial air flow from an inner region of the rotor to an outer region of the rotor.   
   
   
       11 . The fluid dynamic device of  claim 10 , wherein airflow emanating from the rotor enters the fluid intake region of the shroud, is redirected by the shroud and exits the shroud at the fluid exit region. 
   
   
       12 . The fluid dynamic device of  claim 11 , wherein redirection of airflow is at a total angle of airflow, from the fluid intake region of the shroud to the fluid exit region of the shroud, greater than 90 degrees. 
   
   
       13 . The fluid dynamic device of  claim 10 , wherein a yaw torque is produced by a plurality of stator blades which are located within the shroud. 
   
   
       14 . The fluid dynamic device of  claim 13 , wherein the shroud forms an envelope about the drum rotor fan, said envelope including a region below the drum rotor fan in which the plurality of stator blades is placed to produce the yaw torque. 
   
   
       15 . The fluid dynamic device of  claim 14 , wherein, when the air flow is at 90 degrees to the central axis of the shroud, the plurality of stator blades is positioned in a region below the rotor. 
   
   
       16 . The fluid dynamic device of  claim 13 , wherein at least one of said stator blades of the plurality of stator blades are controllably movable so as to effect the degree of yaw torque produced by said at least one stator blade. 
   
   
       17 . The fluid dynamic device of  claim 10 , wherein:
 said device is an airborne craft; and   during acceleration or deceleration of the drum rotor fan, a reaction torque acts on a chassis of the airborne craft in a yaw direction and a counter-rotating mass is provided to counter said reaction torque.   
   
   
       18 . The fluid dynamic device of  claim 17 , further comprising:
 a second drum rotor fan counter-rotating relative to the first drum rotor fan, the second drum rotor fan disposed in the fluid exit region of the shroud.   
   
   
       19 . A fluid dynamic device, comprising:
 a first drum rotor fan having a first rotational direction for generating a radially outward fluid flow;   a shroud for redirecting the radially outward fluid flow from said first drum rotor fan to a region below said first drum rotor fan; and   a second drum rotor fan disposed in said region below the first drum rotor fan, the second drum rotor fan having a second rotational direction.   
   
   
       20 . The fluid dynamic device of  claim 19 , wherein said device is an airborne craft. 
   
   
       21 . The fluid dynamic device of  claim 19 , wherein the second drum rotor fan receives a fluid from the shroud and discharges the fluid radially inwardly towards the rotational axis of the second drum rotor fan. 
   
   
       22 . The fluid dynamic device of  claim 19 , wherein the second rotational direction is opposite to the first rotational direction. 
   
   
       23 . The fluid dynamic device of  claim 19 , further comprising:
 a control means to alter the relative rotational speeds of the first and second drum rotor fans.   
   
   
       24 . An airborne craft, comprising:
 a shroud disposed about a central axis of the device and having an upstream airflow intake region and a downstream airflow exit region, the shroud directing airflow between said upstream airflow intake region and said downstream airflow fluid exit region, the shroud configured so that, at least during some operating conditions of the airborne craft, substantially all of the airflow exiting the airflow exit region is directed towards the central axis.