Low drag ducted Ram air turbine generator and cooling system

Ram air turbine generating apparatus comprising:

• a generally cylindrical external fairing having a leading end, said fairing tapered radially inward toward said leading end with a primary air inlet passage at said leading end, and the external fairing extending to an aft end, and having a plurality of external exhaust ports proximate said aft end,
• a primary structure means radially proximate the inner surface of said external fairing, extending the length of said fairing means, said fairing means mounted to said primary structure, said primary structure including a plurality of straight axial spars extending the length of said external fairing,
• central flow guide means mounted to said support structure and coaxial therewith, said guide means having an outer surface spaced from said structure means,
• centerbody/valve tube means intermediate said primary structure means and said central flow guide means coaxial therewith and in radial proximity to said primary structure means, said centerbodylvalve tube means including an aerodynamically contoured nose end with an aft tubular body with the tube connected to the aft larger valve tube portion of the centerbody/valve tube assembly with aerodynamic shaped spars spanning the increased diameter,
• a plurality of openings therewith set back at a distance from the nose end of said centerbody/valve tube aft end enabling flow of air into and through the openings in said nose end and through an annular passage formed between the inner surface of the valve tube and said center flow guide,
• a turbine wheel having blades and drivingly coupled to a generator or hydraulic pump or both,
• stator means for directing air flow to the turbine blades,
• a plurality of nozzle means, each formed in radial extent in the annular passage between the outer wall of said central flow guide and inner wall of said movable valve tube and in circumferential extent between a set of parallel nozzle side wall means, said nozzle sidewall means consisting of plates mounted to the center flow guide and extending outward within close proximity to the inner wall of said movable valve tube means, and said nozzle side wall means;
• and said nozzle means extending in axial extent from an axial position proximate to the aft end of said primary air inlet in said external fairing and extending afterward to a position in close proximity to said stator,
• said valve tube means being movable between a first position whereat said contoured nose of said valve tube end is in line with the leading edge of said fairing front end such that a maximum area flow area is presented to the air stream in said primary air inlet of said external fairing allowing maximum air flow through said primary air inlet, through said plurality of inlet holes in said contoured nose of said valve tube, through said annular nozzle means, through said stator, through said turbine, through an exhaust deflector and said fairing exhaust ports to a surrounding region;
• and a second position whereat said valve tube is advanced forward so that the contoured nose end of said valve tube restricts the area of said primary air inlet so that reduced airflow occurs through said primary air inlet, through said plurality of inlet holes in the contoured nose of said valve tube, through said annular nozzle means, through said stator, through said turbine, through said exhaust deflector and said fairing exhaust ports to the surrounding region;
• and a third position whereat said valve tube is advanced forward to a maximum forward position so that the contoured nose of the valve tube contacts the inner surface of the fairing primary air inlet in the manner such that the inlet is completely closed,
• speed sensor means for detecting the speed of said turbine wheel;
• and
• an actuator and speed control means responsive to said speed sensor means for moving said valve tube forward toward the second position when the speed of said turbine wheel exceeds a predetermined value, thereby reducing the primary inlet flow area and air flow through the primary air inlet, nozzle means, and to the turbine;
• thereby returning the speed of said turbine wheel to the predetermined speed, said actuator and speed control means responsive to said speed sensor means for moving said valve tube afterward toward the first position when the speed of said turbine wheel is less than a predetermined value, thereby increasing the inlet flow area and air flow through the primary air inlet, nozzle means, to the turbine;
• returning the speed of said turbine wheel to the predetermined speed, said actuator and speed control means responsive to external control for moving said valve tube forward toward the third position when power output is to be stopped thereby completely closing the inlet flow area.