Abstract:
An horizontal axis wind turbine having a rotor ( 3 ) with a frontal projection comprising a stationary spherical head ( 1 ) upstream of its multibladed turbine rotor ( 3 ) displaces and increases the speed of wind addressed over 70% of the total frontal area. A series of thin airfoils ( 12 ) radially and evenly placed on said spherical head ( 1 ) to direct wind towards the turbine short blades ( 4 ).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The inventor has studied examples of present state of the art wind turbines of the propeller type, in particular, as they are now in common use. 
         [0002]    At their apparently low levels of efficiency, another approach had to be made, to better utilize presently well known and commonly applied principles of fluid mechanics and aerodynamics, to improve our ability to extract maximum energy potential from the wind. 
         [0003]    Based on principles of physics and aerodynamics known to the inventor, some serious possibilities were apparent, with numerous novel ways and means of embodying what he has seen as the best combinations of those principles to apply toward greater efficiency in the capture of wind energy. At the present time, there is a fast growing demand for electrical energy in particular, to be produced by means which do not damage the environment. This situation now provides adequate incentive toward the invention and development of wind power based generation of electrical energy, where individual unit capacity might range from a low of 20 kilowatts to as much as 5 megawatts per single unit. 
       OBJECTS OF THE INVENTION 
       [0004]    The objects of this invention are as follows: 
         [0005]    First is the matter of concentrating wind pressure over the entire addressable frontal exposure of its turbine blades, and directing all of the available wind energy toward driving the turbine blades. 
         [0006]    Second is to have the main driven surfaces of its turbine blades situated within the outer thirty percent of the radius between axle center and the outer tips of its turbine blades. This feature greatly increases torque, and ultimate recovery of energy. 
         [0007]    Thirdly, since usual present state of the art wind turbines are quite limited as to being able to provide useable power output at wind speeds below 15 kilometers (9.32 miles) per hour, it is of great advantage to be able to significantly increase oncoming wind speed, to lower the bottom threshold of the operating wind speed range of the wind turbine. The affect of a wind speed increase is cubic in nature, greatly increasing available kinetic energy (wattage per square meter). 
         [0008]    Fourthly, it would be desirable to create or generate a continuously increasing vacuum or a lower pressure induction area behind the turbine blades. 
         [0009]    Fifthly, there would be serious advantage in being able to create the effect of coarser pitch of and to the turbine blades without having to apply any mechanical devices to the rotor or drive axle of the wind turbine. 
       BASIC DESCRIPTION AND IMPROVEMENTS OVER PRESENT STATE OF THE ART 
       [0010]    Based on the objects of this invention, the first improvement over present state of the art is the matter of concentrating the wind energy driving force within the outer 30 percent of the radius between axle center and the outer tips of our turbine rotor blades. A half sphere shape including the outer surface of the turbine rotor, extends forward from the rear of the turbine rotor, in line with axle center, and displaces more than seventy percent of the frontal area of the wind turbine. 
         [0011]    A second improvement is achieved by deployment of the said half sphere shape, including the outer face of the turbine rotor, centered in line with axle center, beginning at the rear face of the said rotor, and extending forward of the turbine rotor from axle center, to front dead center of the said half sphere shape. The portion of the said half sphere shape extending forward from the turbine rotor, is mounted in a fixed stationary position, and does not rotate. The remainder, continuing rearward, as it represents the outer surface of the turbine rotor, rotates as part of the said rotor. This increases incoming wind speed as the wind spreads over the said half sphere shape, and that is a common principle of physics. The wind speed increase lowers the operating wind speed threshold quite significantly, as a clear advantage over present state of the art. The wind speed increase at the surface of the said half sphere shape is ¼ C×R, and that ratio is 1.5707 to 1. That figure is reduced due to surface tension, drag, or friction against flow, and the well known system referred to as Reynolds numbers could be used to determine the approximate drag factor. The inventor&#39;s engineering consultants suggest that the net velocity increase is 46%, and the resulting increase in available kinetic energy amounts to 1.46 cubed, or 311%. 
         [0012]    The third improvement over present state of the art, is the matter of using as many as twenty four comparatively short and properly curved turbine blades of adequate front to back depth, and pitch angle, to achieve maximum torque drive, and further assure that no wind is going to get past the blades, and must drive them all. Blade length must be adequate to catch or encounter all of the wind mass that has been speeded up. This consideration should be rather exact, as a blade length reaching beyond the faster moving wind mass, is going to be entering a slower moving wind mass, which will create drag, resulting in some efficiency loss. This situation provides maximum capture of wind energy, which is converted to the highest amount of torque at our driven axle. It will also be of some further advantage to indent the surface of the stationary spherical head, in front of the turbine rotor, much the same as a golf ball. This could significantly reduce surface tension, resulting in a smoother and faster expanding arc of accelerated wind mass to drive the turbine blades. 
         [0013]    The fourth improvement over present state of the art is where we now have as many as twenty four turbine blades which are generating a significant vacuum induction effect behind the said blades. Three bladed propeller types of wind turbines of present state of the art, are only doing so by means of three blades. In the case of this invention, we are gaining the effect of twenty four blades rather than three blades, and further enhancing the advantage, by assuring there is no effective open area between the blades where that vacuum induction effect can be broken, diminished or lost. 
         [0014]    A fifth, or further potential improvement over present state of the art is the placement of a series of radially and evenly spaced thin airfoils on the periphery of the stationary forward portion of the half sphere, beyond the turbine rotor. The said airfoils would curve incoming wind in a spiral fashion around the half sphere stationary head, in the same direction that the turbine rotor is turning. The advantage to be gained, is that a more open turbine blade pitch can be used with much the same effect as a more closed off blade pitch. This can eliminate the necessity for mechanical means of changing blade pitch when higher speed winds are encountered. For example, if the blade pitch is an average of forty degrees, we can curve the wind coming over the stationary portion of the spherical head by twenty degrees in the direction of rotation, and the turbine blades will operate as though they had a coarser pitch. In the case of rather high wind speeds, the said airfoils can be retracted inward, to zero effect, and the wind turbine rotor blades will then operate at their forty degree pitch. The airfoils can also be made of flexible material which can be progressively curved or bent like a spring. In that case the airfoils would not be retractable, and would remain in place at zero curvature, longitudinally, which would be much the same as being retracted to the point of no affect. The said airfoils are an improvement over present state of the art, where mechanical means are used to vary blade pitch to access incoming wind more efficiently and safely, and to go to neutral, in the case of excessive wind speeds. With state of the art wind turbines, failure of mechanical pitch control, or failure of a governor system could lead to serious damage to the wind turbine. 
         [0015]    In addition to the foregoing improvements over present state of the art, other options are intended, such as utilizing a smaller number of deeper turbine blades, or using a stationary complete half sphere in front of a turbine rotor. The turbine rotor would then have a flat faced purely cylindrical outer surface. It is also likely that we will be able to utilize a form of constant speed or step down transmission, as well as adding more load in the form of further generator capacity, and perhaps magnetic friction heating, to slow down and stabilize the turbine impeller when higher wind speeds are encountered. Since such options could be quite obvious to someone skilled in the art, they are not further included in either the detailed description or drawings to follow. 
         [0016]    It is also apparent to the inventor, that a version of this invention could easily be applied as a wind power drive system for water craft, including ships on the ocean. Its basic features could also be applied as an under water front drive system for water craft. Highly efficient air circulation fans and aircraft propellers are further possibilities. 
     
    
     
       DETAILED DESCRIPTION 
         [0017]      FIG. 1  is a side view of a preferred embodiment of the invention, as mounted on the rotatable top of its support tower platform, with turbine rotor and 24 rotor blades. The turbine rotor has a curved face, being the rearward portion of what would be a completed half sphere shape, including a stationary front portion, separately supported, and mounted closely in front of the said turbine rotor. A close general outline of the outside edge of the path of the wind mass displaced by the spherical head is shown in its broadening arc form, and as it would address a complete cross section of the blades of the wind turbine. This is shown as a broken line arc, from the front center of the stationary portion of the spherical head shape, to the outer tips of the turbine rotor blades. 
           [0018]      FIG. 2  is a frontal view of the same preferred embodiment of the invention, as mounted on the rotatable top of its support tower platform, with turbine rotor and 24 rotor blades. 
           [0019]      FIG. 3  is a side view of the wind turbine, showing relative positions of 12 curved airfoils on the stationary frontal projection of its spherical head, which can be recessed to full closure, and zero effect. They would serve the purpose of curving the oncoming direction of the wind, in the rotational direction of the turbine rotor blades, to add the effect of 20 or more degrees to fixed turbine rotor blades for the purpose of eliminating any necessity for pitch control. 
           [0020]      FIG. 4  is a frontal view of the wind turbine, showing relative positions of the same 12 curved airfoils as illustrated in  FIG. 3 . 
       
    
    
       [0021]    With all of the foregoing in view, and such other and further purposes, advantages or novel features as may become apparent from consideration of this disclosure and specifications, the present invention consists of the inventive concept which is comprised, embodied embraced or included in various specific embodiments of such concept, reference being made to the accompanying figures, in which: 
         [0022]      FIG. 1  is a side view of a preferred embodiment of the invention, as mounted on the rotatable top of its support tower platform, where we have the stationary portion of its spherical head  1 , and the rotating portion of its spherical head  2 , which is also the outer facing of its rotor  3 . Then turbine blades  4 , and the conical shape of its rear outer encasement  5 , and the aerodynamically shaped lower extension  6 , of its outer body and wall, surrounding its supporting structure and internalized access entry port, extending downward to its rotatable base  7 , on top of its tower column,  9 . 
         [0023]    Then we have airfoil shaped structural support beams  8 , for the stationary portion of its spherical head section and its front end axle bearing, then we have the stationary portion of its structural support tower (column)  9 , and broken line representing the outer periphery of the volume expansion area of wind displaced by the said spherical head  10 , and undulating lines  11 , to indicate turbulence expected behind turbine rotor  3 , which would be common to exhausted wind behind the blades of the wind turbine. 
         [0024]      FIG. 2  is a frontal view of the wind turbine, showing the stationary front section of the half sphere shape  1 , rotating curved outer circumferential surface  2 , of turbine rotor  3 , being the remainder of the said half sphere shape. Then we have turbine blades  4 , of which there are twenty four in this embodiment. Also shown are support struts  8 , for the stationary frontal portion of the said half sphere shape and front axle bearing, and rotatable top base mount  7 , for the wind turbine, and then stationary support tower  9 , which would extend to ground level. 
         [0025]      FIG. 3  is an angularly offset side view of another preferred embodiment of the wind turbine, showing relative positions of twelve comparatively thin and retractable airfoils  12 , placed upon and within the stationary frontal projection  1 , of the half spherical shape of more than seventy percent of the radius from axle center to the inside edges or bottom ends of its comparatively short turbine blades  4 . Then we have the conical projection of its rear body or encasement  5 , segmented, as may be necessary for purposes of efficient manufacturing of such projection, and then the somewhat cylindrical and aerodynamically shaped lower extension  6 , of its outer body and wall surrounding its supporting structural elements and internal entry port, and extending downward to its rotatable base  7 , on top of its supporting tower structure  9 . 
         [0026]      FIG. 4  is a direct frontal view of the same preferred embodiment as described in  FIG. 3 , where we can observe curved retractable airfoils  12 , and their relationship to the turbine blades  4 , and we can further see the essential struts  8 , supporting the front axle bearing of the turbine, and carrying the stationary frontal portion of half spherical shape  1 , at the front of the wind turbine. Then we can see further the aerodynamically shaped front end of the bottom extension of the rear housing or embodiment of the wind turbine  6 , and then we have rotatable base support  7 , and stationary support tower  9 .