The cross-flow turbine machine provides shaft power by extracting energy from a moving fluid. The fluid comprises both liquids and gases. Fluid is guided into the rotor by inlet guide means. The fluid then flows through the first rotor, through the interior, through the second rotor, through the exit, and through the diffuser to exit the machine at ambient pressure. Due to the change in angular momentum of the fluid across the turbine rotor, a torque is applied to the output power shaft. The output power shaft can be used, for example, to drive a water pump, an electric generator, or a compressor.

BACKGROUND OF THE INVENTION 
This invention relates to the use of kinetic energy of a moving fluid to 
drive a two dimensional turbine. The turbine can be of arbitrary width and 
hence the output shaft power can be increased by increasing the turbine 
width. The torque of the output shaft can be controlled by varying the 
position of the exit throttle. 
The present invention provides the means to produce shaft power, in 
arbitrary quantities, by extracting kinetic energy from, for example, 
moving air, moving water (for example the Gulf Stream), or moving steam. 
SUMMARY OF THE INVENTION 
The present invention is a device for producing shaft power. The two 
dimensional turbine is of arbitrary width. The kinetic energy of the 
freestream fluid is increased at the entrance of the first rotor by the 
area contraction of the inlet. The inlet shape and guide vanes guide the 
fluid into the rotating inlet turbine vanes. Housing shapes around the 
rotor periphery guide the fluid through the rotating vanes. The fluid is 
guided through the turbine exit by the exit housing. The diffusing area 
housing increases the exiting flow's static pressure to the ambient 
pressure. The boundary layer injection slots along the entire width of the 
machine, between the turbine exit and the diffuser, avoids boundary layer 
separation in the diffuser and significantly augments the quantity of flow 
through the turbine machine. The flow through these slots reduce the 
pressure at the rotor exit much like the pressure is decreased over the 
top of a lifting airfoil. The exit throttle controls the shaft power by 
controlling the exit area and hence the flow rate. The turbine machine has 
a short length to rotor diameter ratio of about 2.5 for low cost and low 
drag, and a low exit height to diameter of about 1.7, also for low drag. 
It is therefore an object of this invention to control and to convert the 
fluid's kinetic energy into shaft power. 
It is another object to provide a turbine which can increase the shaft 
power by increasing the width of the machine. 
It is another object to control the shaft power by controlling the exit 
area. 
These and other objects, features, and advantages of the invention will 
become apparent from the following description taken in conjunction with 
the illustrative embodiment in the accompanying drawings in which like 
numerals identify like elements in the figures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention converts kinetic energy of the moving fluid into 
rotational shaft power by controlling the flow angle and velocity into and 
out of the rotor. Referring to FIG. 1, turbine 1 is shown facing into a 
flow of moving fluid, as shown by arrow 2. The fluid flows through the 
inlet 3, through the inlet rotor vanes 4, through the interior 5, through 
the outlet rotor vanes 6, through the exit 7, through the exit 7, through 
the diffusing nozzles 8 and 9, and exiting the machine with flow velocity 
shown by arrow 10. The interior region 5 is free from flow restriction 
since the rotor shaft 19 is exterior to the flow region. The inlet 3 is 
bounded by guide walls 15 and 16 and entry plane 36. The guide walls 15 
and 16 are shaped to permit satisfactory turbine performance (i.e. to 
avoiding flow separation) over a range of incoming flow angles. The inlet 
guide vanes 17 are arbitrary and when used 17 in cooperation with the 
inlet housing have a continuously decreasing flow area which causes a 
continuous velocity increase from the inlet station 36 of FIG. 1 to the 
rotor inlet station (between the inlet guide vanes and the rotor inlet). 
The guide vanes will also establish the flow angles and velocity, at the 
rotor inlet station, which may be variable around the inlet periphery. The 
rotor 11 rotates in the direction shown by arrow 14. The axis of rotation 
is perpendicular to the incoming fluid flow. The rotor 11 has associated 
therewith vortex forming means 12 which defines the flow gap 13 which 
diverges and then converges in the direction of rotation. The gap 13 will 
form a vortex having a recirculating stream-line shown by arrow 20. The 
vortex forming means controls the circumferential and radial position of 
the naturally ocurring vortex and stabilizes the position of the vortex 
over a range in flows. The radial position of the vortex is increased and 
this considerably increases the interior aerodynamic flow cross sectional 
area which directly increases the maximum flow achievable. The rotor 11 
may have vanes either of the circular arc design 4 and 6 or of the 
aerodynamic design 33. The exterior walls 21, 22, 23, and 24 guide the 
exterior flow, shown by arrows 25 and 26, around the outside of the 
machine. A portion of the exterior flow passes through the gaps 27 and 28; 
the entering flow 29 and 30 energize the inside wall boundary layer flow 
31 and 32. The area at exit plane 35 is controlled by a variable 
positioned vane 34. 
Referring to FIG. 2 there is shown a top view of the cross-flow turbine 
machine 1. The rotor 11 is strengthened by support discs 18 which are 
positioned along the width as required. The power output shaft(s) 19 is 
connected to the end discs 41 and is supported by bearings 38. The 
variable positioned vane 34 is supported by bearings 40, and is rotated by 
rotating the vane shaft 37 about its center as shown by arrow 39. The exit 
vane 34 is a means of controlling the exit flow area which therefore 
controls the flow through the turbine machine. The vane can be controlled 
by a suitable control system which is not discussed herein. The fact that 
the exit area controls the flow in such devices is documented in a study 
by G. J. Harloff, "Cross Flow Fan Experimental Development and Finite 
Element Modeling," Ph.D. Dissertation, U. of Texas at Arlington 1979.