Abstract:
A reciprocating internal combustion engine used a crankshaft to develop rotating motion. A rotary pulse detonation engine can be adapted to rotate a shaft. A combustor portion of the rotary pulse detonation engine is spaced from an axis of the shaft a preestablished distance therebetween in a mass member. An intake portion and an exhaust portion of the combustor portion is positioned in a parameter of the mass member. A combustion portion of the combustor portion is interposed the intake portion and the exhaust portion. The combustion portion has a frustoconical first position which converges to form a deflagration wave and progresses into a detonation. The deflagration to detonation transition occurs in the transition region. A combustible fuel and air mixture is combusted in the combustor portion creating a high speed jet exiting the exhaust portion and rotating the shaft.

Description:
TECHNICAL FIELD 
     This invention relates generally to an engines and more particularly to a pulse detonation engine having a high power density propulsion application. 
     BACKGROUND 
     A reciprocating internal combustion engine is widely used to transform chemical energy of a fuel into mechanical energy. Such engines have a complex mechanical combination of components used to transform the chemical energy into rotational motion. For example, a block has a cylinder formed therein and the cylinder is closed at an end by a head having a plurality of intake and exhaust valves therein. A piston having a connecting rod attached thereto is positioned in the cylinder and forms a combustion chamber. As combustion occurs within the combustion chamber, the piston is moved axially and the connecting rod which is attached to a crankshaft causes the crankshaft to rotate within the block to form the rotational motion. The complexity of mechanical components and the motion thereof results in a low efficiency of the reciprocating internal combustion engine. Additionally, the power-to-weight ratio is limited due to sliding friction, material temperature resistance and combustion pressure resistance. 
     Rotary engines reduce the mechanical complexity by eliminating the need to transform the reciprocating piston motion into the rotational motion of the crankshaft. However, the rotary engine does not substantially improve the efficiency or the power-to-weight ratio over the reciprocating internal combustion engine. 
     A rotary detonation engine has been suggested to overcome the power-to-weight ratio and to increase efficiency. One such rotary detonation engine is shown in U.S. Pat. No. 4,741,154 issued on May 3, 1988 to Shmuel Eidelman. It is speculated that the detonation engine of Eidelman has many shortcomings. A portion of such shortcomings being the introduction a continuous detonation mixture and the introduction of the detonation mixture within or near a shaft supporting a plurality of a rotor elements. Other shortcomings too numerous to define are contemplated such as distributing the detonation mixture to individual ones of the rotor elements. 
     The present invention is directed to overcoming one or more of the problems as set forth above. 
     SUMMARY OF THE INVENTION 
     In one aspect of the invention a pulse detonation engine has a shaft defining an axis; a mass member being positioned on the shaft, the mass member having a preestablished width and defining a parameter; a combustor portion being positioned in the mass member, the combustor portion being spaced from the axis a predetermined distance and defining an intake portion having a portion thereof positioned in the parameter and an exhaust portion having a portion thereof positioned in the parameter. 
     In another aspect of the invention a system for rotating a shaft, comprises: the shaft having an axis; a mass member being positioned on the shaft, the mass member having a preestablished width “W” and defining a parameter; a pulse detonation engine positioned in the mass member, the pulse detonation engine having a combustor portion being positioned in the mass member, the combustor portion being spaced from a predetermined distance and defining an intake portion having a portion thereof positioned in the parameter and an exhaust portion having a portion thereof positioned in the parameter; a compressor member being upstream of a flow of fuel and air entering the intake portion of the combustor portion; a mixer member being interposed the compressor member and the intake portion of the combustor portion; and an intake manifold being interposed the mixer member and the intake portion of the combustor portion. 
     In another aspect of the invention a method of rotating a shaft comprises: compressing an atmospheric air; mixing the compressed atmospheric air with a fuel forming a combustible fuel and air mixture; attaching a mass member to the shaft, the mass member defining a parameter and the shaft having an axis; positioning a pulse detonation engine in the mass member, the pulse detonation engine having a combustor portion being positioned in the mass member, the combustor portion being spaced from the axis a predetermined distance and defining an intake portion having a portion thereof positioned in the parameter and an exhaust portion having a portion thereof positioned in the parameter; supplying the combustible fuel and air mixture to the intake portion of the combustor portion; igniting the combustible fuel and air mixture; causing a high speed jet to exit the exhaust portion; and rotating the shaft as a result of the high speed jet. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic representation of a system using a compact rotary pulse detonation engine therein; 
     FIG. 2 is a more detailed schematic view of the compact rotary pulse detonation engine taken along an axis of a driven shaft; 
     FIG. 3 is a sectional view taken alone line  3 — 3  of FIG. 2; and 
     FIG. 4 is a view taken line  4 — 4  of FIG.  3 . 
    
    
     DETAILED DESCRIPTION 
     In FIG. 1 a system  10  includes a shaft  12  having a compact rotary pulse detonation engine  14  axially positioned on the shaft  12 . The compact rotary pulse detonation engine  14  or a combination thereof is attached to the shaft  12  in a conventional manner. The shaft  12  has an axis  15 . The system  10  includes a compressor member  16 , such as a blower, turbocharger or any other compressing device  16 . The compression member  16  is positioned upstream of the compact rotary pulse detonation engine  14 . In this application, the compressor member  16  has a housing  18  in which is positioned an inlet portion  20  and an outlet portion  22 . A pair of gears  24  are positioned within the housing  18  and one of the pair of gears  24  is driven by the shaft  12  in a conventional manner. For example, the driven gear  24  may be driven mechanically, electrically, pneumatically or any conventional manner of driving an accessory member. As an alternative, the compressor member may be driven externally of the shaft  12 . A flow of atmospheric air, designated by arrow  26  enter the inlet portion  20  of the compressor member  16 . 
     The system  10  includes a mixer member  30  interposed the compressor member  16  and the compact rotary pulse detonation engine  14 . The mixer member  30  includes a housing  32  having an air inlet portion  34  and a fuel inlet portion  36 . A fuel and air outlet portion  38  is positioned in the housing  32  and has a flow of mixed fuel and air, designated by an arrow  40  exiting therefrom. 
     The system  10  includes a fuel supply  42  being in fluid communication with the fuel inlet portion  36  of the mixer member  30  in a conventional manner. A plurality of fuels can be used with the compact rotary pulse detonation engine  14  and include any conventional fuel. The fuel can be in a solid, liquid, or gaseous state. Although in this application, a gaseous state is illustrated and nature gas is the example of the fuel used herewith. 
     As shown in FIG. 2, the system  10  has a control mechanism  44  of conventional configuration. For example, in this application a flapper valve  44  is used and is infinitely operable between an open position  46  and a closed position  48 , shown in phantom. Other types of control mechanism  44 , such as a poppet mechanism or a variable displace mechanism could be used without changing the gest of the invention. 
     As shown in FIG. 2, the mixed fuel and air  40  of the system  10  enters an inlet portion  50  of an intake manifold  52 . In FIG. 2, four compact rotary pulse detonation engines  14  are spaced axially along the shaft  12  and the axis  15 . As an alternative, any number of compact rotary pulse detonation engines  14  could be positioned on the shaft  12 . The intake manifold  52  has a plurality of feeder portion  54  radically positioned about a parameter  56  of the respective one of the compact rotary pulse detonation engines  14 . In this application, a feeder exhaust portion  62  is radically positioned about the parameter  56  of the respective one of the compact rotary pulse detonation engines  14 . Each of the feeder exhaust portions  62  is connected with an exhaust manifold  64 . The exhaust manifold  64  has an outlet portion  66  in communication with the atmosphere through a muffler  68 . As an alternative, the exhaust manifold  60  and components following therefrom could be eliminated if desirable. 
     As shown in FIG. 2, a mechanical drive  80  includes a gear  82  and a second shaft  84  connected to the main shaft  12  in a conventional manner. The second shaft  84  is connected to the driven gear  24  of the compressor member  16  in a conventional manner. 
     As best shown in FIG. 3, the compact rotary pulse detonation engine  14  has a mass member  86 , which in this application has a circular configuration defining the parameter  56  and a preestablished width “W”. The mass member  86  could have other configurations such as triangular, hexagonal or square without changing the gist of the invention. The compact rotary pulse detonation engine  14  has a combustor module  90  positioned in the mass member  86 . In this application, as best shown in FIG. 1, two combustor module  90  per compact rotary pulse detonation engine  14  is shown; however, any number of combustor module  90  can be employed without changing the gist of the invention. The combustor module  90  includes a intake portion  92  and an exhaust portion  94  positioned at the parameter  56  of the compact rotary pulse detonation engines  14 . Interposed the intake portion  92  and the exhaust portion  94  is a combustion portion  96 . The intake portion  92  includes an intake valve mechanism  98 , which in this application is a rotary intake valve mechanism being operable in a conventional manner. As best shown in FIG. 4, the rotary intake valve mechanism  98  is operated between an open position  100  and a closed position  102  shown in phantom. As an alternative, the intake valve mechanism  98  could be of any conventional design such a shutter mechanism, a flapper mechanism or a poppet mechanism. Positioned in the intake portion  92  is an igniter  104 , which in this application is a spark plug. The combustion portion  96  includes a duct  106  having a generally frustoconical first portion  108  and a second portion  110  having a preestablished cross-sectional area. The frustoconical first portion  108  converges to form a deflagration region  112  and progressed into a detonation region  114 . The deflagration region  112  and the detonation region  114  form a transition portion  116 . The second portion  110  in this application has a generally circular cross-sectional configuration, however, other cross-sectional configurations such as a square, rectangular, oval or hexagonal could also be used without changing the gist of the invention. And, the exhaust portion  94 , in this application, also has a generally circular cross-sectional configuration, however, other cross-sectional configurations such as square, rectangular, oval or hexagonal could also be used without changing the gist of the invention. 
     In this application the combustor module  90  has an axis  120  which is spaced from the axis  15  of the shaft  12  a preestablished distance. In this application, the axis  120  has a straight configuration between the inlet portion  92  and the exhaust portion  94 . However, as an alternative, the axis  120  could have a radiused configuration without changing the gest of the invention. 
     Industrial Applicability 
     In operation, the system  10  has the atmospheric air  26  drawn into the inlet portion  20  of the compressor member  16  and the pair of gears  24  compress the atmospheric air  26  increasing the temperature and pressure thereof After being compressed the atmospheric air  26  passes through a cooler, not shown. The cooler may be an internal cooler, intercooler or may be positioned externally without changing the jest of the invention. From the cooler, the compressed air  26  enters the air inlet portion  34  of the mixer member  30  and fuel, from the fuel supply  42  enters the fuel inlet portion  36  of the mixer member  30 . Within the mixer member  30  the air and fuel are mixed to form the combustible mixture of fuel and air  40 . The combustible mixture of fuel and air  40  enter the intake manifold  52  and is distributed to each of the plurality of feeder portions  54 . And, with the respective rotary intake valve mechanism  98  in the open position  100  the flow of the combustible mixture of fuel and air  40  enters the inlet portion  92 . The respective rotary intake valve mechanism  98  is moved into the closed position  102  and the spark plug  104  is detonated igniting the combustible mixture of fuel and air  40 . After ignition the mixture begins as a deflagration wave. Rapid expansion of the gas in the burned region increases the pressure/temperature and causes a transition to a detonation. The detonation region  114  creates supersonic combustion and a shock precedes a flame front greatly increasing the reaction rate raising the temperature of the unburned mixture of fuel and air  40 . With the frustoconical configuration a quick deflagration to detonation transition  116  takes place and detonation waves propagate along the combustion portion  96  toward and through the exhaust portion  94 . The detonating wave results in combustion of the fuel and air mixture  40  that is two orders of magnitude faster than ordinary combustion such as that of the reciprocating internal combustion engine. And, the pressure in the exhaust portion  94  behind the detonation wave front is one or two orders of magnitude higher than the initial pressure. Because of the high pressure in the exhaust portion  94  behind the detonation wave, the products are ejected from the exhaust portion  94  in the form of high speed jets which causes the mass member  86  to rotate abut the axis  15  of the shaft  12 . A rotational speed of the compact rotary pulse detonation engine  14  can be controlled by the control mechanism  44 . With the control mechanism  44  in the fully open position  46  a high rate of speed can be developed; however, with the control mechanism  44  very near the closed position  48  a slow speed is developed. By varying the position between the open position  46  and the closed position  48  a wide range of speeds can be developed. 
     The compact rotary pulse detonation engine  14  provides an alternative to the reciprocating internal combustion engine. The compact rotary pulse detonation engine  14  has less heating of the walls of the combustion portion  96  and the exhaust portion  94  since the combustion process occurs much more quickly. Thus, since less heat is rejected more fuel per unit time can be used and the compact rotary pulse detonation engine  14  has the capacity to generate more power per unit engine. Each combustor module  90  can generate a high specific impulse. And, with the increased pressure of combustion the compact rotary pulse detonation engine  14  result in a thermodynamically more efficient combustion. 
     Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.