Abstract:
The self-starting turbineless jet engine has fuel delivery, fuel combustion and airflow components, but it does not contain and therefore avoids the limitations associated with turbines or other moving parts other than those associated with the fuel delivery. The jet engine provides inlet louvers or vanes which direct air through an internal restriction to before mixing it with a fuel for combustion in a combustion chamber. While most of the combustion gases are exhausted through an outlet portion of the turbineless jet engine, a portion of the combustion gases are mixed with air received from an aft inlet duct in sixteen thermodynamic air compressors and back through a centrally located hot gas and fire pressure conduit where the gases are further redirected by a high temperature insulated nose cone back into the air flow received by the inlet louvers, thereby providing heat and air compression, even at zero airspeed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 12/458,548, filed Jul. 15, 2009, which is a continuation of U.S. patent application Ser. No. 12/219,805, filed Jul. 29, 2008, now U.S. Pat. No. 7,563,418, issued Jul. 21, 2009, which claimed the benefit of U.S. provisional patent application Ser. No. 60/996,780, filed Dec. 5, 2007. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to jet engines, and more specifically, to a self-starting turbineless jet engine that includes fuel delivery, fuel combustion, and corresponding airflow constraints, but which incorporates no turbines or other moving parts other than those associated with the fuel delivery. 
         [0004]    2. Description of the Related Art 
         [0005]    While jet engines employing turbines have received both long-term and widespread adoption for both commercial and military aviation applications, other jet engines, such as ramjet engines with no internal moving parts beyond their fuel delivery systems, have not seen widespread adoption. Note that as used herein, the term “ramjet” is taken to including sub-sonic, sonic and supersonic RAM jet engines unless designated otherwise. 
         [0006]    A ramjet uses its own forward motion to compress incoming air without a turbine or other rotary compressor. When a ramjet is moving at sufficiently high speed through air, the physical configuration of the ramjet creates a high pressure region in front of the engine and a corresponding low pressure region to the rear of the engine, leading to a large pressure differential. This large pressure differential forces air into a tube within the ramjet where internal constraints on airflow cause the air to be compressed. The compressed air is ultimately combusted with fuel and released to the rear of the engine to provide thrust. A variety of liquid and solid fuels can be used as long as those fuels combust sufficiently well to maintain the necessary airspeed for continuous ramjet operation. 
         [0007]    Modern materials, manufacturing techniques and design simulations have reached a level of sophistication sufficient to produce workable ramjet engines. Furthermore, ramjets can outperform turbine-based jet engine designs at certain supersonic speeds and are more fuel efficient than rockets over much of their working range. The performance of ramjet engines exceeds that of turbine-based jet engines, in part because the extreme temperatures and pressures associated with supersonic travel place severe demands on rotating turbine blades, while ramjets do not have turbines or comparable moving internal parts. However, current ramjet engines have other limitations that do not exist with turbine-based jet engines. 
         [0008]    A typical ramjet design relies upon the internal pressure differential produced by a shockwave developed within the engine as air passes from supersonic to subsonic flow. This is achieved by carefully shaped and contoured surfaces within the engine, which accelerate and decelerate the airflow as desired. The result is an engine that is capable of producing useful amounts of thrust at high speed, including supersonic speeds, with no moving parts. However, current ramjet engines are severely limited because they cannot produce thrust at zero airspeed, and thus cannot move an aircraft from a standstill. As a result, ramjet engines require some other form of propulsion to provide the requisite minimum air velocity for operation. Because the other form of propulsion incurs its own costs and issues, ramjets have not been seen as practical for many civilian and military applications. There is a need for a turbineless jet engine that can produce thrust from a standstill so that no additional form of propulsion is required. Thus, a self-starting turbineless jet engine solving the aforementioned problems is desired. 
       SUMMARY OF THE INVENTION 
       [0009]    The self-starting turbineless jet engine provides inlet louvers that direct air through an internal restriction before mixing it with a fuel for combustion in a combustion chamber. While most of the combustion gases are exhausted through an outlet portion of the turbineless jet engine, a portion of the combustion gases are mixed with air received from an aft inlet duct. A combustion chamber is disposed radially around a center axis of the turbineless jet engine and feeds a relatively small portion of the combustion gases back through a centrally located hot gas and fire pressure conduit where the combustion gases from the combustion chamber are combined and redirected by a high temperature insulated nose cone back to the aft side of the inlet louvers. By having a separate path for a small portion of the combustion gases and a large portion of unburned air to be reintroduced back into the combustion chamber, the turbineless jet engine can provide heat and air compression to produce thrust, even at zero airspeed. 
         [0010]    The self-starting turbineless jet engine is not limited to any one particular fuel. In some embodiments, fuel is provided by hydrogen, which may be provided by the Hydrogen Generator for Jet Engines, as disclosed in my prior U.S. Pat. No. 7,563,418, issued Jul. 21, 2009. In some other embodiments, a different fuel delivery device vaporizes a liquid hydrocarbon fuel for combustion. The liquid hydrocarbon fuel can be jet fuel, such as Jet A, Jet A-1, Jet B, etc. 
         [0011]    While the primary airflow paths in the engine contain no moving parts, the fuel delivery mechanism uses a fuel pump air motor. The fuel pump air motor is operated by exhaust gas from the combustion section of the engine once the engine is in operation, thereby eliminating the need for electrical and/or other power for the engine in some embodiments, except during start-up. 
         [0012]    These and other advantages of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a diagrammatic side view in section of a self-starting turbineless jet engine according to the present invention. 
           [0014]      FIG. 2  is a front view in section of a self-starting turbineless jet engine according to the present invention, taken approximately through a thermodynamic heat exchanger portion of the engine. 
       
    
    
       [0015]    Similar reference characters denote corresponding features consistently throughout the attached drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]    The self-starting turbineless jet engine produces thrust from a fuel source using no internal moving parts, except for the fuel delivery system. Compared to more commonplace turbine-based jet engines, there are no compressors or other rotating machinery inside the jet engine. 
         [0017]      FIG. 1  of the drawings provides a side view in section, largely diagrammatic, of the self-starting turbineless jet engine  10  according to some preferred embodiments of the present invention. While the view of  FIG. 1  only shows two separate combustion areas, oriented one above the other and with their associated inlets and outlets, as shown in  FIG. 2 , in preferred embodiments there is a single combustion chamber positioned radially around a central axis of the jet engine  10 . 
         [0018]    The jet engine  10  of  FIG. 1  includes fourteen louvered air inlets  12  disposed radially around a central axis of the jet engine  10  for receiving air from outside of the jet engine  10 . Note that one or more jet engines  10  may be physically coupled to an aircraft, rocket, projectile or other airborne object. The louvered air inlets  12  receive outside air in the path illustrated in  FIG. 1 , as traveling in a left to right direction relative to the jet engine  10 . For illustration purposes, the forward facing portions of the jet engine  10  face predominantly left, while the rearward facing portions of the jet engine  10  face predominantly right. 
         [0019]    The air inlet section  14  also receives a portion of the exhaust gases, as described below, to pass aft of the louvers  12  at high speed to pump air into the air inlet section, so that the air is heated and further compressed within the air inlet section  14 . Air in the air inlet section  14  passes a starter high temperature steam injector  16  before reaching an air inlet constriction portion  18 . The starter high temperature steam injector  16  injects high temperature steam, which undergoes rapid expansion, in order to force more air through the air inlet constriction portion when the jet engine is being started. The steam injector  16  is only needed in startup conditions. The steam injector  16  is under control of a central processor unit (CPU)  50  so that once the jet engine  10  reaches sufficient power, the steam injector is no longer used. Air is accelerated through the air inlet constriction portion  18  because of the reduced opening. Air that has passed through the air inlet constriction portion  18  encounters uncombusted fuel from a nozzle  20 . In some preferred embodiments, the fuel released from the nozzle  20  is hydrogen. 
         [0020]    The hydrogen emitting nozzle  20  is fully described in the inventor&#39;s prior U.S. Pat. No. 7,563,418, issued Jul. 21, 2009, which is hereby incorporated by reference in its entirety, i.e., the nozzle  20  comprises the hydrogen generator described in the aforementioned patent. Briefly stated, the nozzle  20  or hydrogen generator includes a tungsten screen cathode disposed around an anode made from carbon steel, iron, nickel and chromium. The anode is, in turn, disposed around a pipe that delivers steam. When current is applied to the anode and the cathode, the anode and cathode are heated until they become white-hot, which superheats the steam. The superheated steam is sprayed into the space between the anode and cathode, and is thermolytically converted to ionized oxygen and hydrogen. The ionized hydrogen is attracted by the negatively charged cathode, and passes through the cathode to the combustion chamber. It will be understood, however, that other sources of hydrogen fuel may be provided and injected into the combustion chambers through suitable nozzles. The hydrogen generator of the &#39;418 patent is preferred because the anode and cathode become white-hot during the process of generating hydrogen, which heats the air-fuel mixture in the jet engine  10 , leading to more complete combustion of the air-fuel mixture in the combustion chambers, with greater resultant thrust. 
         [0021]    In other embodiments, the fuel is a hydrocarbon-based jet fuel, such as Jet A, Jet A-1, Jet B, or other commercially available jet fuel, etc. When the fuel used is a hydrocarbon-based jet fuel, the nozzle  20  will be of a type well known in the art. 
         [0022]    Fuel injected from the nozzle  20  is mixed into the incoming air to create an air-fuel mixture and is combusted. A flame holder  22  is used to slow a portion of the air-fuel mixture to provide more consistent combustion ignition, occurring, in part, in a combustion chamber  23  area. While combustion occurs in the combustion chamber  23 , it is not limited to the combustion chamber  23 . Most combustion gases from the combustion chamber  23  are exhausted through an air outlet section  24  without any further travel within the jet engine  10 . However, some of the combusting air-fuel mixture is redirected towards a central horizontal axis of the jet engine into a thermodynamic air compressor  25  that contains venturis  26 . The venturis  26  compress the combusting air-fuel mixture and further allow the introduction of outside air into the jet engine  10  via an aft inlet duct  28  (shown at the top and bottom in  FIG. 1 ) disposed radially around the jet engine  10 . 
         [0023]    The aft inlet duct  28  represents a second point of entry into the jet engine  10  for outside air, the first being the louvered air inlets  12 . Air received by each of the aft inlet ducts  28  is divided and forced into thirty-two (32) corresponding aft inlet heat exchanger inlet pipes  30  that pass air to the venturis  26 , where the air passes between the venturis  26  into the combusting air-fuel mixture. The insertion of outside air at this point provides additional oxygen and pressure, which helps to force the combusting air-fuel mixture into a central hot gas and fire pressure conduit  32 . Air passing through all sixteen groups of venturis  26  disposed radially around the central axis of the jet engine  10  is forced into the central hot gas and fire pressure conduit  32 , where the flow is redirected towards the forward facing portions of the jet engine  10 . 
         [0024]    A small portion of the gases in the central hot gas and fire pressure conduit  32  is diverted into an air motor inlet duct  34 , where it is used to interact with an air motor  36  to rotate a fuel pump shaft  38 . After the small portion of the gases from the central hot gas and fire pressure conduit  32  interact with the air motor  36 , they are exhausted through an air motor outlet duct  40 . The fuel pump shaft  38  turns a constant speed drive (CSD)  42  of a type known in the art. The CSD  42 , in turn, drives an electrical motor-generator  44  and a fuel pump  46 . The electrical motor-generator can receive and consume electrical energy from a set of batteries  48  under control of the CPU  50  in order to turn the fuel pump shaft  38 , or can be turned by the fuel pump shaft  38  to generate electrical energy. In either case, the fuel pump shaft  38  is turning, which causes the fuel pump  46  to deliver fuel to the nozzle  20 . 
         [0025]    Most of the gases in the central hot gas and fire pressure conduit  32  continue past the air motor inlet duct  34  in a forward direction, generally opposite to the direction of the air entering the engine through the louvered air inlets  12 , until encountering a high temperature insulated nose cone  52 . The gases in the central hot gas and fire pressure conduit  32  are deflected by the nose cone  52  back into the air inlet section  14 , where they quickly pass aft of the louvers  12  and effectively pump air into the inlet section  14  of the jet engine  10  to be heated and compressed. 
         [0026]    The jet engine  10  also contains air pathways for cooling purposes. A small amount of air is removed from the air inlet section  14  inside the jet engine  10  via cooling air inlets  54 . Air passes from the air inlet section  14  through the cooling air inlets  54  into a cooling air conduit  56 . Air inside the cooling air conduit  56  cools outer surfaces of the central hot gas and fire pressure conduit  32  and the thermodynamic air compressor  25  before passing through outlet gaps  58  into the air outlet section  24 , and are vented back into the atmosphere through exhaust aperture  60  in the air outlet section  24 . Air exhausted through the air motor outlet duct  40  is also exhausted into the cooling air conduit  56 . 
         [0027]      FIG. 2  shows a front view in section taken approximately through the thermodynamic heat exchanger  25 . From this view, one can see a front portion of the sixteen venturis  26  disposed radially around the central hot gas and fire pressure conduit  32  in the jet engine  10 . Between the venturis  26  are the sixteen cooling air conduits  56 . Extending radially past the cooling air conduits  56  are front portions of the thirty-two aft inlet heat exchanger inlet pipes  30  that pass air to the sixteen venturis  26 , which are located to the sides and behind the leading or frontmost portions of the aft inlet heat exchanger inlet pipes  30 . The combustion chamber  23  is positioned radially adjacent to the front portions of the aft inlet heat exchanger inlet pipes  30 . Finally, outside air is received by the aft inlet duct  28 , and follows the path indicated by the arrows in  FIG. 2 . 
         [0028]    With regard to both  FIG. 1  and  FIG. 2  and from an airflow perspective in start-up, the CPU  50  uses electrical power from the batteries  48  to power the electrical motor-generator  44  and a fuel pump  46 . If the fuel is hydrogen, the CPU  50  also directs electrical power from the batteries  48  to four nozzles  20  to photodissociate the water into hydrogen and oxygen in order to start the engine  10 . Alternatively, if the fuel is a hydrocarbon-based fuel, all twelve hydrocarbon spray nozzles  20  can be operated simultaneously, as desired. The CPU  50  also provides electrical power for the hot steam injectors  16  to begin airflow in the jet engine  10 . If the fuel is hydrogen, the high temperature hydrogen produced in the nozzle  20  will be ignited upon contact with oxygen in the air. If the fuel is a hydrocarbon, a separate igniter of the conventional type (not shown) is used to ignite the fuel. 
         [0029]    Regardless of fuel type, fuel mixes with air, and the resultant air-fuel mixture is combusted in the combustion chamber  23  (and elsewhere) with assistance of the flame holder  22 . In some embodiments, roughly 80 to 85% percent of the air-fuel mixture is combusted and leaves the jet engine  10  directly through the air outlet section  24  to produce thrust, while the remaining 15-20% is diverted through the venturis  26  in the thermodynamic air compressor  25  and driven into the central hot gas and fire pressure conduit  32  in the jet engine  10 . Hot gases in the central hot gas and fire pressure conduit  32  encounter the high temperature insulated nose cone  52 , and are redirected back into the air inlet section  14  before returning to the high temperature steam injector  16  and passing into the air inlet constriction portion  18 . 
         [0030]    Thrust produced by the jet engine  10  will eventually accelerate the engine and produce increasing levels of compressed air received by the louvered air inlets  12  and the aft inlet duct  28  for use in the jet engine  10 . In typical circumstances, the jet engine  10  will reach desired operating conditions, including speed and thrust. As the jet engine  10  accelerates towards the desired operating conditions, the CPU  50  can correspondingly reduce the amount of electrical energy provided by the batteries  48  and rely instead on electrical energy generated by the electrical motor-generator  44 . 
         [0031]    In conclusion, the self-starting turbineless jet engine, in its various embodiments, provides a practical alternative to current ramjet designs because of its self-starting capability. Furthermore, the lack of moving or rotating parts, outside of fuel delivery, greatly reduces the manufacturing costs and labor associated with current turbine-based jet engines. The engine  10  has the ability to operate without the need for external electrical power once it has been sufficiently started. 
         [0032]    It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.