Abstract:
The present invention provides a diesel engine and methods and apparatus for premixing diesel fuel and oxidant for combustion. The methods and apparatus may include a two stage vortex, each stage accommodating different flow rate ranges. The vortex pulverizes diesel fuel and optimally mixes the diesel fuel with an oxidant prior to introduction into a combustion chamber. The premixing results in more complete combustion and, consequently, fuel efficiency is increased and pollution is decreased.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Rudolf Diesel developed the first diesel engine and obtained a German patent for it in 1892. His goal was to build an engine with high efficiency. Gasoline engines had been invented in 1876 and, especially at that time, were not very efficient.  
         [0002]     Unlike gasoline engines that ignite mixtures of gas and air with a spark, a diesel engine intakes air, compresses the air, and injects fuel into the compressed air, such that the heat and pressure of the compressed air ignites the fuel spontaneously. Diesel engines do not have spark plugs or other ignition sources. Some older diesel engines include glow plugs to warm the cylinders in cold conditions, but the glow plugs are not ignition sources; rather, they are resistive warming elements.  
         [0003]     Pistons of typical gasoline engines compress at a ratio of between 8:1 and 12:1, while a diesel engine normally compresses at a ratio of 14:1 to 25:1. The higher compression ratio of the diesel engine leads to more torque and better fuel efficiency. The use of diesel fuel allows the compression ratios of diesel engines to be much higher than for gasoline engines. Gasoline auto-ignites at lower temperatures and pressures that diesel fuel, and auto-ignition results in knock in gasoline engines.  
         [0004]     Diesel fuel has a higher auto-ignition temperature than gasoline and is heavier and oilier than gasoline. Diesel fuel evaporates much more slowly than gasoline—its boiling point is actually higher than the boiling point of water. Diesel fuel contains more carbon atoms in longer chains than gasoline does (gasoline is typically primarily C 9 H 20 , while diesel fuel is typically primarily C 14 H 30 ). Crude oil also requires less refining to create diesel fuel, which is why diesel fuel is generally cheaper than gasoline.  
         [0005]     Diesel fuel also has a higher energy density than gasoline. On average, one gallon (3.8 L) of diesel fuel contains approximately 155×10 6  joules (147,000 BTU) of energy, while one gallon of gasoline contains 132×10 6  joules (125,000 BTU) of energy. This higher energy density, combined with the improved efficiency of high compression diesel engines, explains why diesel engines get better fuel economy than equivalent gasoline engines.  
         [0006]     The fuel injector of a diesel engine is usually its most complex component and has been the subject of a great deal of experimentation—in any particular engine it may be located in a variety of places. The injector must withstand the temperature and pressure inside the cylinder and still deliver the fuel in a fine mist. Circulating the mist of fuel in the cylinder so that it is evenly distributed is also a common problem.  
         [0007]     Even distribution of the diesel fuel within the cylinder and mixing the fuel with air contribute to the completeness of combustion of the diesel fuel. To optimize fuel oxidation within an engine&#39;s combustion chamber, the fuel/air mixture is ideally vaporized or homogenized to achieve a chemically-stoichiometric gas-phase mixture. Ideal fuel oxidation results in more complete combustion and lower pollution.  
         [0008]     Relative to internal combustion engines, stoichiometricity is a condition where the amount of oxygen required to completely burn a given amount of fuel is supplied in a homogeneous mixture resulting in optimally correct combustion with no residues remaining from incomplete or inefficient oxidation. Ideally, the fuel should be completely vaporized, intermixed with air, and homogenized prior to entering the combustion chamber for proper oxidation. Non-vaporized fuel droplets generally do not ignite and combust completely in conventional diesel engines, which presents problems relating to fuel efficiency and pollution.  
         [0009]     Incomplete or inefficient oxidation of diesel fuel causes exhaustion of residues from the diesel engine as pollutants, such as unburned hydrocarbons, carbon monoxide, and aldehydes, with accompanying production of oxides of nitrogen. To meet emission standards, these residues must be dealt with, typically requiring further treatment in a catalytic converter or a scrubber. Such treatment of these residues results in additional fuel costs to operate the catalytic converter or scrubber. Accordingly, any reduction in residues resulting from incomplete combustion would be economically and environmentally beneficial.  
         [0010]     Aside from the problems discussed above, a fuel-air mixture that is not completely vaporized and chemically stoichiometric causes the combustion engine to perform at less than peak efficiency. A smaller portion of the fuel&#39;s chemical energy is converted to mechanical energy when fuel is not completely combusted. Fuel energy is wasted and unnecessary pollution is created. Thus, by further breaking down and more completely vaporizing the fuel-air mixture, higher compression ratios and better fuel efficiency may be available.  
         [0011]     Many attempts have been made to alleviate the above-described problems with respect to fuel vaporization and incomplete fuel combustion. Diesel fuel injectors spray a somewhat fine fuel mist directly into the cylinder of the engine and are controlled electronically. Nevertheless, the fuel droplet size of a fuel injector spray is not optimal and there is little time for the fuel to mix with air prior to ignition. Even current fuel injector systems do not fully mix the fuel with the necessary air.  
         [0012]     Moreover, it has been recently discovered that fuel injector sprays are accompanied by a shockwave in the fuel spray. The shockwave may prevent the fuel from fully mixing with air. The shockwave appears to limit fuel mass to certain areas of the piston, limiting the fuel droplets&#39; access to air.  
       SUMMARY  
       [0013]     The principles described herein may address some of the above-described deficiencies and others. Specifically, some of the principles described herein relate to liquid processor apparatuses and methods.  
         [0014]     One aspect provides a method comprising fueling a diesel engine. The fueling comprises creating a gaseous, homogenous premixture of diesel fuel and oxidizer in a first pre-combustion vortex chamber and introducing the gaseous, homogenous premixture of diesel fuel and oxidizer from the first pre-combustion vortex chamber into a combustion chamber. According to one aspect, the method further comprises minimizing or preventing shockwaves in the combustion chamber. One aspect comprises igniting the gaseous, homogenous premixture of diesel fuel and oxidizer with an ignition source.  
         [0015]     According to one aspect of the method, creating a gaseous, homogenous premixture of diesel fuel and oxidizer comprises creating an oxidizer vortex in the first pre-combustion vortex chamber, introducing diesel fuel at an axis of the oxidizer vortex, and pulverizing the diesel fuel and mixing the diesel fuel with the oxidizer at an axial area of the first pre-combustion vortex chamber. According to one aspect, creating a gaseous, homogenous premixture of diesel fuel and oxidizer comprises creating an oxidizer vortex in the first pre-combustion vortex chamber, introducing diesel fuel at an axis of the oxidizer vortex, pulverizing the diesel fuel and mixing the diesel fuel with the oxidizer, wherein the creating an oxidizer vortex comprises introducing the oxidizer into the first pre-combustion vortex chamber at a non-tangential, non-radial angle through multiple fluid passageways.  
         [0016]     According to one aspect of the method, creating a gaseous, homogenous premixture of diesel fuel and oxidizer comprises providing a primary stage oxidizer introduction path, providing a secondary stage oxidizer introduction path, opening a valve in the secondary stage oxidizer introduction path upon reaching a predetermined oxidizer requirement threshold, creating an oxidizer vortex in a second pre-combustion vortex chamber with fluid flow from the secondary stage oxidizer introduction path, introducing diesel fuel at an axis of the oxidizer vortex, pulverizing the diesel fuel and mixing the diesel fuel with the oxidizer. According to one aspect, the valve in the primary stage oxidizer introduction path remains open with the opening of the valve in the secondary stage oxidizer introduction path.  
         [0017]     One embodiment comprises an a diesel engine. The diesel engine comprises a block, one or more combustion chambers or cylinders disposed in the block, a reciprocating member disposed in each of the one or more combustion chambers, and a pre-combustion diesel fuel mixing device fluidly connected to the one or more combustion chambers. According to one embodiment, the pre-combustion diesel fuel mixing device comprises a housing, a first pre-combustion vortex chamber enclosed by the housing, a plurality of angled passages leading into the first pre-combustion vortex chamber for creating a vortex, and a first oxidant fluid flow path in fluid communication with the first pre-combustion vortex chamber. One embodiment further comprises an ignition device extending into each of the one or more combustion chambers. The ignition device may comprise a spark plug.  
         [0018]     According to one embodiment of the diesel engine, the pre-combustion diesel fuel mixing device comprises a second pre-combustion vortex chamber enclosed by the housing and aligned axially with the first pre-combustion vortex chamber, the second pre-combustion vortex chamber being larger than the first pre-combustion vortex chamber, a plurality of angled passages leading into the second pre-combustion vortex chamber for creating a vortex, and a second oxidant fluid flow path in fluid communication with the second pre-combustion vortex chamber. According to one embodiment, the angled passageways are non-tangential and non-radial.  
         [0019]     One embodiment of the diesel engine further comprises a first diverging nozzle leading out of the first pre-combustion vortex chamber, the first diverging nozzle comprising a plurality of lateral passages angled opposite of the plurality of angled passages leading into the first pre-combustion vortex chamber. According to one embodiment, the diesel engine further comprises a conical pillar adjacent to an outlet of the pre-combustion diesel fuel mixing device.  
         [0020]     According to one embodiment of the diesel engine, the pre-combustion diesel fuel mixing device comprises a second pre-combustion vortex chamber enclosed by the housing and aligned axially with the first pre-combustion vortex chamber. The second pre-combustion vortex chamber may be larger than the first pre-combustion vortex chamber. According to one embodiment, a plurality of angled passages lead into the second pre-combustion vortex chamber for creating a vortex. In one embodiment, the diesel engine may also comprise a second oxidant fluid flow path in fluid communication with the second pre-combustion vortex chamber and a throttle body housing a valve. In one embodiment, the valve controls fluid flow through the second oxidant fluid flow path.  
         [0021]     One embodiment of the diesel engine further comprises a fuel injector aligned substantially axially with the first and second pre-combustion vortex chambers. The fuel injector comprises an axial flow channel, and a plurality of radial flow channels.  
         [0022]     One embodiment of the diesel engine further comprises a turbocharger. In one embodiment, the pre-combustion diesel fuel mixing device is fluidly connected between the turbocharger and the one or more combustion chambers. According to one embodiment, the pre-combustion diesel fuel mixing device further comprises a fuel injector disposed in a cylindrical cavity of the housing and in fluid communication with the first and second pre-combustion vortex chambers, the fuel injector comprising a liquid flow channel and a vent in fluid communication between the liquid flow channel and an oxidant flow introduction path.  
         [0023]     One aspect provides a method comprising operating a diesel engine. Operating the diesel engine comprises creating a gaseous, homogenous premixture of diesel fuel and oxidizer in a first pre-combustion vortex chamber, flowing the gaseous, homogenous premixture of diesel fuel and oxidizer into a cylinder of the diesel engine, compressing the gaseous, homogenous premixture of diesel fuel and oxidizer in the cylinder with a piston at a ratio of at least about 15:1 without causing auto-ignition of the gaseous, homogenous premixture of diesel fuel and oxidizer, and igniting the gaseous, homogenous premixture of diesel fuel and oxidizer. According to one aspect, igniting comprises creating a spark with a spark plug in the cylinder. In one aspect, the method further comprises compressing the gaseous, homogenous premixture of diesel fuel and oxidizer in the cylinder with a piston at a ratio greater than 21:1 without causing auto-ignition of the gaseous, homogenous premixture of diesel fuel and oxidizer. According to one aspect, creating a gaseous, homogenous premixture of diesel fuel and oxidizer comprises maintaining a combustible mixture while reducing the diesel fuel to an average particle size such that compressing the gaseous, homogenous premixture of diesel fuel and oxidizer in the cylinder with a piston at a ratio of at least 25:1 does not cause auto-ignition of the gaseous, homogenous premixture of diesel fuel and oxidizer. According to one aspect, the method further comprises compressing the gaseous, homogenous premixture of diesel fuel and oxidizer in the cylinder with a piston at a ratio of at least 30:1 or 40:1 without causing auto-ignition of the gaseous, homogenous premixture of diesel fuel and oxidizer  
         [0024]     One embodiment provides an apparatus comprising a diesel engine fuel premixing device. The device comprises a two stage vortex chamber. A first stage is in fluid communication with a first oxidation flow path, and a second stage is in fluid communication with a separate, second oxidation flow path. The device includes a fuel injector arranged circumferentially internal of the first and second stages and a diesel engine fluidly connected to the diesel engine premixing device. In one embodiment, the diesel engine comprises spark plugs. According to one embodiment, the first stage, the second stage, and the fuel injector are substantially coaxial. According to one embodiment, the first stage comprises a high vacuum, low flow rate vortex chamber, and the second stage comprises a larger volume than the first stage and comprises a low vacuum, high flow rate vortex chamber. In one embodiment, the first and second stages comprise low and high flow rate vortex chambers, respectively, that may be subject to positive pressures as well as vacuum pressures.  
         [0025]     One embodiment of the apparatus further comprises a first nozzle disposed at an outlet to the first stage. The first nozzle may comprise fluid passages arranged both in a vortex direction and a direction opposite of the vortex direction. The opposite arrangement of the fluid passages in the first nozzle may direct fluids pulverized by the first stage axially in a generally non-rotational flow. One embodiment of the apparatus further comprises a diverging nozzle at an outlet of the second stage.  
         [0026]     One embodiment comprises a pillar arranged adjacent to the diesel engine premixing device for centering a vortex created in the first or second stages. In one embodiment, the fuel injector comprises axial and radial ports for injecting fuel into the first and second stages. According to one embodiment, the device is infinitely adjustable between oxidant fluid flow directed to the first and second stages. According to one embodiment, only the first oxidation source is open to the first stage until a predetermined flow rate is reached, and the second oxidation source is also opened when the predetermined flow rate is reached. One embodiment further comprises a water jacket disposed about the first stage of the two stage vortex chamber.  
         [0027]     One aspect provides a method comprising fueling a diesel automobile. The method comprises premixing diesel fuel with an oxidant. The premixing comprises introducing diesel fuel into an oxidant vortex to create a premixed diesel fuel and oxidant mixture, and introducing the premixed diesel fuel and oxidant mixture into a combustion chamber of the automobile without forcing additional diesel fuel into the combustion chamber. According to one aspect, the premixing comprises providing first and second vortex chambers in series, such that the first vortex chamber only or both the first and second vortex chambers receive a supply of oxidant. The oxidant may enter the first or second vortex chamber at an angle and create the oxidant vortex. According to one aspect, the method includes providing a fuel injector and injecting fuel axially. Injecting may comprise injecting diesel fuel axially into the oxidant vortex created by either one of the first or second vortex chambers. According to one aspect, the premixing comprises centering and holding the oxidant vortex. According to one aspect, the drawing comprises evenly distributing the premixed diesel fuel and oxidant into a manifold.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]     The accompanying drawings illustrate certain embodiments discussed below and are a part of the specification.  
         [0029]      FIG. 1  is a cross sectional view of a diesel engine with a fuel mixing apparatus according to one embodiment.  
         [0030]      FIG. 2  is a cross sectional view of the diesel engine and fuel mixing apparatus shown in  FIG. 1 , with a piston compressing an air/fuel mixture according to one embodiment.  
         [0031]      FIG. 3  is a magnified cross sectional view of the mixing apparatus in relation to an intake manifold of the diesel engine according to one embodiment.  
         [0032]      FIG. 4  is a perspective assembly view of a set of vortex creating components shown in  FIG. 3 , prior to enclosure within a housing.  
         [0033]      FIG. 5  is a perspective view of the components shown in  FIG. 4  following assembly.  
         [0034]      FIG. 6A  is a perspective view of an injection nozzle used in the mixing apparatus according to one embodiment.  
         [0035]      FIG. 6B  is a cross sectional view of the injection nozzle shown in  FIG. 6A .  
         [0036]      FIG. 7  is a perspective view of the mixing apparatus of  FIG. 3 . 
     
    
       [0037]     Throughout the drawings, identical reference characters and descriptions indicate similar, but not necessarily identical elements.  
       DETAILED DESCRIPTION  
       [0038]     Illustrative embodiments and aspects are described below. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, that will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.  
         [0039]     As used throughout the specification and claims, the term “pre-combustion chamber” refers to an area that is not a combustion area. The words “including” and “having,” as used in the specification, including the claims, have the same meaning as the word “comprising.” 
         [0040]     Turning now to the figures, and in particular to  FIGS. 1-2 , one embodiment of a diesel engine  10  is shown. As known to those of ordinary skill in the art having the benefit of this disclosure, the diesel engine  10  may include a number of standard components. For example, the diesel engine  10  of  FIGS. 1-2 , includes a block  12 . At least one bore in the block  12  may comprise one or more combustion chambers, for example one or more cylinders  14 . A reciprocating member, such as a piston  16 , is disposed in each of the one or more cylinders  14 . The piston  16  is connected to a crank shaft  18  by a tie rod  20 . One or more valves  20 ,  22  open and close at certain times during a diesel cycle to introduce air and fuel, and exhaust combusted products. Fresh air and fuel may enter the cylinder  14  through a first passageway  26  via the first valve  20 , and exhaust may exit the cylinder  14  through the second valve  22  leading to an exhaust passageway  28 . The diesel engine may operate generally according to well known principles, described in part above, to produce work from diesel fuel by combusting the diesel fuel in the cylinders  14 . However, although standard diesel engines do not include spark plugs, according to one embodiment, an ignition source such as a spark plug  24  may extend into or be associated with, each cylinder  14 . Some of the reasons for including the spark plug  24  or another ignition source are discussed below. Other known components may also comprise parts of the diesel engine  10 .  
         [0041]      FIG. 1  illustrates an intake stroke of the diesel engine  10 . The first valve  20  is open to the first passageway  26 . As the piston  16  retracts, a premixture of diesel fuel and air is drawn into the cylinder  14 .  FIG. 2  illustrates a compression stroke of the diesel engine  10 . The valves  20 ,  22  close, and the piston  16  compresses the air and fuel mixture in the cylinder  14 . In a normal diesel engine, the piston  16  compresses only air in the cylinder  14 , and pressurized diesel fuel is directly injected by a fuel injector into the cylinder. In addition, the compression tends to generate sufficient heat and pressure to auto-ignite standard mixtures of diesel fuel and air in the cylinder. However, according to one embodiment discussed herein, diesel fuel is not fuel injected, instead the diesel fuel and oxidant are premixed before entering the cylinder  14  or other combustion chamber. Moreover, according to some embodiments, it is expected that compression ratios of up to about 15:1, over about 21:1, up to 25:1, and even up to 40:1 or more do not cause the premixed diesel fuel and oxidant to auto-ignite. Therefore, according to one embodiment, the spark plug  24  or other ignition source is associated with the cylinder  14  to initiate combustion.  
         [0042]     One reason engine compression ratios as high as 40:1 or more may not cause auto-ignition is the very fine, homogenous mixture of diesel fuel and oxidant supplied to the engine  10 . According to one embodiment, the diesel engine  10  includes and is fueled by a mixing apparatus that may reduce the particle size of a majority of the diesel fuel to 50 μm or smaller. According to one embodiment, the mixing apparatus may reduce the particle size of a majority of the diesel fuel to 20 μm or smaller, for example the mixing apparatus may pulverize at least 80-95% of the diesel fuel to a particle size of approximately 1-3 μm or smaller. The mixing apparatus may comprise, for example, a pre-combustion diesel fuel mixing device  100 . The pre-combustion diesel fuel mixing device  100  may provide a premixed supply of diesel fuel and oxidant to an internal combustion engine or other device.  FIGS. 1-3  illustrate the pre-combustion diesel fuel mixing device  100  fully assembled and in cross-section.  FIG. 3  is a magnified illustration of the pre-combustion diesel fuel mixing device  100  and is primarily referenced below for clarity in identifying elements described.  
         [0043]     As shown in  FIG. 3 , according to one embodiment, the pre-combustion diesel fuel mixing device  100  comprises a housing  102 . The housing  102  is a generally rigid structure that may be made of metal, ceramic, composite, plastic, or other materials. The housing  102  encloses a number of internal components which are described below. The housing  102  is shown in perspective view in  FIG. 7 . The housing  102  may comprise any size or shape, although as shown in  FIG. 7 , some embodiments of the housing  102  include an oxidant inlet section  104  and a vortex section  106 . The oxidant inlet section  104  may comprise a throttle body as shown in  FIG. 7 .  
         [0044]     Returning to  FIG. 3 , the housing  102  -encloses a first pre-combustion vortex chamber or first stage  108 . The first pre-combustion vortex chamber  108  comprises a first axis  109 . A plurality of angled passages  110  lead into the first pre-combustion vortex chamber  108 . The plurality of angled passages  110  facilitate the creation of a vortex or tornado in the first pre-combustion vortex chamber  108 . A first oxidant flow introduction path  112  disposed in the housing  102  is in fluid communication with the first pre-combustion vortex chamber  108 . The first oxidant flow introduction path  112  provides a primary air or oxidant source to the first pre-combustion vortex chamber  108 . A set of arrows  114  indicates the direction of the flow of air or other oxidant through the first oxidant flow introduction path  112  into the first pre-combustion vortex chamber  108 . A first valve  116  disposed in the first oxidant flow path  112  may comprise an electronically controlled valve to regulate the flow or flow rate of air into the first pre-combustion vortex chamber  108  based on need.  
         [0045]     The plurality of angled passages  110  leading into the first pre-combustion vortex chamber  108  may comprise slots formed in and spaced around a periphery of a wheel such as first vortex wheel  118 . The first vortex wheel  118  is most clearly shown in the perspective view of  FIG. 4 . The first vortex wheel  118  may comprise a generally rigid structure and may be made of metal, plastic, ceramic, composite, or other materials. The first vortex wheel  118  is coaxial with first axis  109 . The angled passages  110  of the first vortex wheel  118  may be non-tangential, and non-radial. That is to say, the angled passages  110  comprise an angle from tangent greater than zero degrees and less than ninety degrees (ninety degrees is perfectly radial or centered). The angled passages  110  may be angled between about ten and seventy degrees. The angled passages  110  may range between about five and fifty degrees. The angled passages  110  may be at least about thirty degrees from tangent. Thus, the angled passages  110  tend to facilitate creation of a vortex in the first pre-combustion vortex chamber  108  as air is introduced therein. The vortex tends to be spaced internal of the first wheel  118 , as the angled passages  110  are non-tangential.  
         [0046]     According to one embodiment, the first vortex wheel  118  is adjacent to and in contact with a hat  120 . The hat  120  is generally circular and attached to the housing  102 . The hat  120  may be semi-spherical or dish shaped and extend partially into the center of the first vortex wheel  118 . For example, a spherical portion  122  of the hat  120  may extend approximately half way into the center of the first vortex wheel  118 . The hat  120  may comprise metal, plastic, ceramic, composite, or other material. As best shown in  FIG. 3-5 , the hat  120  may be coaxial with the first vortex wheel  118 . The hat  120  also includes a central hole  124  that may define a cylindrical cavity. The central hole  124  of the hat  120  is receptive of an injector, such as fuel injector  126 .  
         [0047]     According to one embodiment, the fuel injector  126  may be coaxial with the first wheel and the hat  120 . The fuel injector  126  may include a flange  128  that connects the fuel injector  126  to the hat  120  and creates a seal. However, a head  130  of the fuel injector  126  inserts into the central hole  124  of the hat  120 . The diameter of the central hole  124  and the diameter of the head  130  of the fuel injector  126  are sized to leave an annulus  132  between an inner surface of the central hole  124  and an outer surface of the head  130 . The fuel injector  126  also includes a tail  134  that may extend outside of the housing  102 . The fuel injector  126  is in fluid communication with a fuel source.  
         [0048]     According to one embodiment, the fuel injector  126  may include an inlet  135  and multiple fluid or liquid ports. For example, according to the embodiment of  FIGS. 6A-6B , the fuel injector  126  includes an axial flow channel  136  and a plurality of radial flow channels  138 , each in fluid communication with the inlet  135 . According to the embodiment of  FIGS. 6A-6B , there are four equally spaced radial flow channels  138 . In addition, the fuel injector  126  may include one or more pressure equalization vents, such as vents  140 . The vents  140  may fluidly communicate with the first oxidant flow introduction path  112  via a conduit  113  ( FIG. 3 ), and there may be one vent  140  in fluid communication with each of the radial flow channels  138 . Therefore, according to  FIGS. 6A-6B , there are four vents  140 . The atmospheric vents  140  prevent a pressure differential at the radial flow channels  138  and thus the axial flow channel  136 . The vents  140  equalize pressure at the flow channels  136 ,  138  even in positive pressure situations (due, for example, to turbocharging).  
         [0049]     Returning to  FIGS. 3-4 , according to one embodiment, the annulus  132  may provide a gap large enough to eliminate any flow restriction of fluids exiting the head  130  radially through the radial flow channels  138  ( FIG. 6B ). That is to say, the size or diameter of the radial flow channels  138  tends to limit flow capacity rather than the annulus  132 . The fuel injector  126  is arranged radially inside a circumference of the first pre-combustion vortex chamber  108  and introduces fuel to the first pre-combustion vortex chamber  108  at the axis  109 , rather than laterally through the angled passages  110 .  
         [0050]     According to the embodiment of  FIGS. 1-7 , the first vortex wheel  118  is arranged adjacent to and may contact a first output nozzle  142 . The first output nozzle  142  is arranged coaxially with the first vortex wheel  118  and may comprise a diverging nozzle made of metal, plastic, ceramic, composite, or other material. The first output nozzle  142  may include a hemispherical hat  144  that extends partially into the first vortex wheel  118 . A lip  146  around the hemispherical hat  144  may provide a contact or resting surface for the first vortex wheel  118 . The lip  146  may sit on an internal protrusion  147  of the housing  102 . Accordingly, the first output nozzle  142  may be suspended within the housing  102  as shown in  FIG. 3 .  
         [0051]     According to one embodiment, the first output nozzle  142  comprises a central hole  148  that is open to the first pre-combustion vortex chamber  108 . In addition, the first output nozzle  142  includes a plurality of small angled passages extending laterally therethough at different angles. For example, according to the embodiment of  FIG. 4 , the first output nozzle  142  includes a first set of angled passages  150  in the hemispherical hat  144  and a second set of angled passages  150 ,  152  in a conical tail portion  154 . The first and second sets of angled passages  150 ,  152  may include passages directing fluid in both clockwise and counter-clockwise directions. There may be any number of passages in the clockwise and counter-clockwise directions, and there may be a substantially equal number in each direction to create a non-vortical or non-rotational flow through the first output nozzle  142 .  
         [0052]     According to one embodiment, the first output nozzle  142  leads to a second pre-combustion vortex chamber or second stage  158 . Together with the first pre-combustion vortex chamber  108 , the second pre-combustion vortex chamber forms a two stage vortex chamber. The second pre-combustion vortex chamber  158  may be coaxial with the first axis  109 . The second pre-combustion vortex chamber  158  is larger than the first pre-combustion vortex chamber  108  and may comprise a radius at least twice as large as the radius of the first pre-combustion vortex chamber  108 . A second plurality of angled passages  160  lead into the second pre-combustion vortex chamber  158 . The second plurality of angled passages  160  facilitate the creation of a vortex or tornado in the second pre-combustion vortex chamber  158 . A second or secondary oxidant flow introduction path  162  disposed in the housing  102  is in fluid communication with the second pre-combustion vortex chamber  158 . The secondary oxidant flow introduction path  162  is larger than the first oxidant flow introduction path  112 . The secondary oxidant flow path  162  provides air or another oxidant source to the second pre-combustion vortex chamber  158 . Arrows  164  indicate the direction of the flow of air or other oxidant into the second pre-combustion vortex chamber  158  and through the second set of angled passages  152  in the conical tail portion  154  of the first output nozzle  142 . A valve such as a second or butterfly valve  166  disposed in the second oxidant flow path  162  may comprise an electronically or mechanically controlled valve to regulate the flow rate of air into the second pre-combustion vortex chamber  158  based on need. The larger secondary oxidant flow path  162  and second pre-combustion vortex chamber  158  accommodate high fluid flow rates as needed. If mechanically controlled, the butterfly valve  166  may be connected by a cable  168  to a pedal or throttle such as a gas pedal  170  of an automobile.  
         [0053]     According to one embodiment, the plurality of angled passages  160  leading into the second pre-combustion vortex chamber  158  may comprise slots formed in and spaced around a periphery of another wheel such as second vortex wheel  172 . The second vortex wheel  172  is most clearly shown in perspective view in  FIG. 4 . The second vortex wheel  172  may be larger—and according to some embodiments at least twice as large—as the first vortex wheel  118 . The second vortex wheel  172  may comprise a generally rigid structure and may be made of metal, plastic, ceramic, composite, or other materials. The second vortex wheel  172  is coaxial with the first axis  109 . The angled passages  160  of the second vortex wheel  172  may be non-tangential, and non-radial. The angled passages  160  comprise an angle from tangent greater than zero degrees and less than ninety degrees. The angled passages  160  may be angled between about ten and seventy degrees. The angled passages  160  may range between about five and fifty degrees. The angled passages  160  may be at least about thirty degrees from tangent. Thus, the angled passages  160  tend to facilitate creation of a vortex in the second pre-combustion vortex chamber  158  as air is introduced therein. The vortex tends to be spaced internal of the second wheel  172 , as the angled passages  160  are non-tangential. The second vortex wheel  172  may include a lid  174  with a central hole  176  open to the first output nozzle  142 , and a plurality of smaller holes  178 . A restrictor plate  156  may be disposed in the central hole  176 . The restrictor plate  156  may be curved or funneled as shown in the embodiment of  FIG. 4 . The angled passages  160  may be formed between cantilevered protrusions  175  extending from the lid  174 .  
         [0054]     According to one embodiment, the second vortex wheel  172  may rest on and may be attached to a closing plate  180 . The closing plate  180  may be substantially flush with the housing  102  and includes a central hole  182  coaxial with the first axis  109 . An inner ring  184  of the closing plate  180  may support a second or final outlet nozzle  186 . The second outlet nozzle  186  and the closing plate  180  may comprise generally rigid structures and may be made of metal, plastic, ceramic, composite, or other materials. The second outlet nozzle  186  may comprise an interior diverging nozzle as best shown in  FIG. 3 . The second outlet nozzle  186  may include a generally cylindrical outer portion  188  and an outer lip  190  having a diameter greater than the generally cylindrical portion  188 . The generally cylindrical outer portion  188  is sized to slide into the central hole  182  of the closing plate  180 , but the outer lip  190  limits the insertion depth. The outer lip  190  comprises a diameter that is larger than the diameter of the central hole  182 . According to one embodiment, the second outlet nozzle  186  straddles the closing plate  180  and extends partially into the interior of the second vortex wheel  172 . According to one embodiment, the first and second vortex chambers and one or more of the other components described above may comprise an axially aligned vortex assembly.  
         [0055]     According to one embodiment, the second outlet nozzle  186  leads out of the pre-combustion fuel mixing device  100  and may provide a premixture of gaseous, homogenous diesel fuel and oxidizer to a combustion chamber such as cylinder  14 . According to one embodiment, the pre-combustion diesel fuel mixing device  100  is arranged adjacent to an intake manifold  194  that distributes the premixture of gaseous, homogenous diesel fuel and oxidizer to several combustion chambers, such as the diesel engine  10  cylinders  14  ( FIG. 1 ). Further, some embodiments include an intake pillar, such as a conical pillar  196 , at the second outlet nozzle  186 . The conical pillar  196  may be part of the intake manifold  194 . However, according to some embodiments the conical pillar  196  may also be part of and attached to the pre-combustion diesel fuel mixing device  100 .  
         [0056]     According to one embodiment, the conical pillar  196  is coaxial with the first axis  109 . The conical pillar  196  may be made of metal, plastic, ceramic, composite, or other materials. The conical pillar  196  may tend to center or hold the vortexes formed in either the first or second pre-combustion vortex chambers  108 ,  158 . Centering or holding the vortexes formed in either the first or second pre-combustion vortex chambers  108 ,  158  may aid in the pulverizing and mixing of the fuel into the premixture of gaseous, homogenous fuel and oxidizer. Centering the vortexes with the conical pillar  196  also tends to evenly distribute the premixture of gaseous, homogenous fuel and oxidizer into each of the various intake passageways of the intake manifold  194  leading to combustion chambers, such as the first passageway  26  leading to the cylinder  14  as shown in  FIGS. 1-2 .  
         [0057]     The conical pillar  196  may take on many forms. According to one embodiment, the conical pillar  196  comprises at least two different slopes. For example, a first conic surface  198  may have a first slope, and a second conic surface  200  may have a second slope steeper than the first slope. However, the conical pillar  196  may have a single slope according to one embodiment, and the second conic surface  200  may be replaced by a cylindrical surface according to some embodiments. As shown in the embodiments of  FIGS. 1-7 , the conical pillar  196  may comprise a peripheral lip  202  between the first and second conic surfaces  198 ,  200 . The peripheral lip  202  may provide a collection area for any liquids that fall out of the premixture of gaseous, homogenous diesel fuel and oxidizer created by the vortexes. As the flow of gaseous, homogenous diesel fuel and oxidizer passes by the conical pillar  196 , it tends to “drag” with it some of the liquids that collect at the peripheral lip  202 .  
         [0058]     According to one embodiment, the housing  102  may define a heat exchanger such as a water cooling jacket  103 . The water cooling jacket  103  is in fluid communication with the cooling system of the diesel engine and arranged around the first pre-combustion vortex chamber  108 . The water cooling jacket  103  comprises an internal fluid passageway of the housing  102  and may heat oxidant flowing through the first oxidant flow introduction path  112 . The water cooling jacket  103  primarily cools the engine and operates in steady state conditions at approximately 190-212° F.  
         [0059]     According to some aspects, the pre-combustion diesel fuel mixing device  100  facilitates methods of mixing diesel fuel with oxidant. For example, some aspects provide methods of fueling a diesel engine. According to one aspect, diesel fuel is mixed with an oxidant by axially introducing fuel into an oxidant vortex. For example,-diesel fuel may be axially introduced into either or both of the first and second pre-combustion vortex chambers  108 ,  158  via the fuel injector  126 . In some cases, engine action creates a vacuum to draw air or other oxidant into one or both of the first and second pre-combustion vortex chambers  108 ,  158 . In other cases, such as when a turbocharger is used, engine action creates positive pressure to push air or other oxidant into one or both of the first and second pre-combustion vortex chambers  108 ,  158 . The arrangement of the angled passages  110 ,  160  into each of the first and second pre-combustion vortex chambers  108 ,  158  creates a vortex when air is drawn or pushed therein. Moreover, according to one embodiment, vortexes created in either of the first and second pre-combustion vortex chambers  108 ,  158  are held and centered by naturally attaching to the conical pillar  196 .  
         [0060]     According to one embodiment, diesel fuel is introduced axially (as opposed to tangentially or radially or laterally through circumferential slots such as the angled passages  110 ,  160 ) into the first and second pre-combustion vortex chambers  108 ,  158  to pulverize or atomize the fuel and create a gaseous, homogenous premixture of diesel fuel and oxidizer. According to one embodiment, the pulverizing action is in an axial area spaced from the outer walls (at the angled passages  110 ,  160 ).  
         [0061]     According to some embodiments, the gaseous, homogenous premixture of diesel fuel and oxidizer is drawn from the first and/or second vortex chambers  108 ,  158  into a combustion chamber such as the cylinder  14 . According to one embodiment, neither the fuel nor oxidant is injected or injected under pressure into the cylinder  14 . Instead, according to one embodiment, the premixture of fuel and oxidant is drawn into the cylinder  14  by vacuum (created, for example, by the reciprocation of the piston  16  in the cylinder  14 ). Therefore, shockwaves that accompany typical diesel fuel injection systems may be prevented in the cylinder  14 . Further, the premixture of diesel fuel and oxidant drawn into the cylinder  14  by vacuum may be more likely to evenly distribute within the cylinder  14  to fill the vacuum. Nevertheless, according to one embodiment, the premixture of diesel fuel and oxidant may be pressurized and injected into the cylinder  14 , especially by a turbocharger or supercharger. However, even positive pressure embodiments omitting a fuel injector at the cylinder  14  continue to minimize the occurrence of shockwaves in the cylinder  14 .  
         [0062]     According to some embodiments, the first vortex chamber  108  operates either alone or in combination with the second-vortex chamber  158 . For example, the butterfly valve  166  disposed in the second oxidant flow path  162  may be normally closed (but may allow a small amount of oxidant to leach thereby and enter, for example, the angled passages  152  of the first outlet nozzle  142 ). The valve  116  and the fuel injector  126  may be operated in electronic or mechanical coordination to provide a combustible ratio of fuel and oxidant based on need and/or engine speed. According to one embodiment, the first vortex chamber  108  comprises a high vacuum, low flow rate vortex chamber, and therefore the valve  116  is normally open when an engine needs a low flow rate of gaseous, homogenous diesel fuel and oxidizer. The first vortex chamber  108  may also comprise a positive pressure, low flow rate vortex chamber as most diesel engines include a turbocharger or a supercharger. The valve  116  may be infinitely adjustable to provide an appropriate amount of oxidant for introduced fuel.  
         [0063]     According to one embodiment, when combustion needs require a higher flow rate of gaseous, homogenous premixture of diesel fuel and oxidizer than the first oxidant flow path  112  can reasonably provide, the butterfly valve  166  may also open. For example, in one embodiment, the first oxidant flow path  112  can provide air mass flow rates ranging between approximately 0 and 262 lbm/hr. The second oxidant flow path  162  can provide higher flow rates of oxidant into the second pre-combustion vortex chamber  158  than the first oxidant flow path  112  can provide to the first pre-combustion vortex chamber  108 . Therefore, the second pre-combustion vortex chamber  158  may comprise a low vacuum, high flow rate vortex chamber. The second pre-combustion vortex chamber  158  may also comprise a positive pressure, high flow rate vortex chamber as a result of turbocharging or supercharging. In one embodiment, the second oxidant flow path  162  can provide air mass flow rates ranging between approximately 0 and 1400 lbm/hr. In other embodiments, the second oxidant flow path  162  can provide air mass flow rates greater than 1400 lbm/hr. A “low” flow rate refers to a mass flow rate of less than approximately 262 lbm/hr. A “high” flow rate refers to a mass flow rate of more than approximately 262 lbm/hr. The butterfly valve  166  may also be infinitely adjustable to provide an appropriate amount of oxidant for introduced fuel. In one embodiment, the butterfly valve  166  is only opened after the valve  116  is fully open. Because the first and second pre-combustion vortex chambers  108 ,  158  are aligned axially in some embodiments, the same fuel injector  126  may provide fuel to both chambers. It will be understood by one of ordinary skill in the art having the benefit of this disclosure, however, that the ranges of flow rates mentioned above are exemplary in nature and the flow paths  112 ,  162  may be altered to provide other flow ranges as well.  
         [0064]     According to one embodiment, flow through the first and second oxidant flow paths  112 ,  162  is additive. That is to say, when the valve  116  is fully open and additional flow capacity is necessary, the butterfly valve  166  is opened as well. For example, in one embodiment, the valve  116  may adjust flow rate between approximately 0 and 262 lbm/hr, and the butterfly valve  166  may be opened to increase flow rate capacity from 262 lbm/hr to 1400 lbm/hr or more. According to one embodiment, the butterfly valve  166  is mechanically connected to the gas pedal  170  of an automobile such that when the gas pedal is depressed to a predetermined level or a predetermined oxidizer requirement threshold is met, the valve  116  is fully open and the butterfly valve  166  opens. Nevertheless, according to one embodiment, the valve  116  and the butterfly valve  166  may each be only partially open.  
         [0065]     According to one aspect, the pre-combustion diesel fuel mixing device  100  is in operation with the valve  116  in the first oxidant flow introduction path or source  112  open. Oxidant enters the first pre-combustion vortex chamber  108  and creates a vortex. Diesel fuel is introduced into the center of the vortex of the first pre-combustion vortex chamber  108 , which pulverizes the fuel and creates the gaseous, homogenous premixture of diesel fuel and oxidizer. The gaseous, homogenous premixture of diesel fuel and oxidizer passes through the first outlet nozzle  142 , through the second pre-combustion vortex chamber  108 , and out the second outlet nozzle  186 . According to some embodiments, which may include the conical pillar  196 , the flow of gaseous, homogenous premixture of diesel fuel and oxidizer is evenly distributed though the intake manifold  194  and drawn under vacuum or introduced at positive pressure into one or more cylinders  14  or other combustion chambers.  
         [0066]     According to one aspect, the pre-combustion diesel fuel mixing device  100  is in operation with the butterfly valve  166  in the second oxidant flow introduction path or source  162  open. Oxidant enters the second pre-combustion vortex chamber  158  and creates a vortex. Diesel fuel is introduced into the center of the vortex of the second pre-combustion vortex chamber  158 , which pulverizes the fuel and creates the gaseous, homogenous premixture of diesel fuel and oxidizer. The gaseous, homogenous premixture of diesel fuel and oxidizer passes through the second outlet nozzle  186  and is evenly distributed though the intake manifold  194  and drawn under vacuum pressure or injected under positive pressure into one or more combustion chambers such as cylinder  14 .  
         [0067]     According to one aspect, the pre-combustion diesel fuel mixing device  100  operates to fuel an automobile and varies an air-to-fuel ratio. For example, in one embodiment, the valves  116 ,  166  operate automatically (either electronically programmed or a mechanical control) to vary air-to-fuel ratio based on engine speed and the load on the engine. In one embodiment, intake manifold absolute pressure is monitored, which is representative of the load on the engine.  
         [0068]     In one embodiment, the automatic variation of the air-to-fuel ratio may follow parameters of a lookup table, a formula, or other feature. Under some conditions, it is believed that a stoichiometric air-to-fuel ratio is ideal. However, some engine conditions may result in better fuel efficiency, more power, or other desired performance characteristics, at non-stoichiometric air-to-fuel ratios. The stoichiometric air-to-fuel ratio for diesel is approximately 14.3 to 14.5:1. That is to say, a stoichiometric mixture of diesel and air comprises 14.3 to 14.5 parts air for every one part diesel, depending on the composition of the diesel fuel. Nevertheless, according to some embodiments, the pre-combustion diesel fuel mixing device  100  is operated to vary the air-to-fuel ratio. Generally, according to some aspects, at reduced loads, which may include idle or highway cruising conditions, the air-to-fuel ratio tends to be increased, in some conditions to ratios well above stoichiometric. At higher loads, on the other hand, the air-to-fuel ratio may be decreased, sometimes below stoichiometric.  
         [0069]     The preceding description has been presented only to illustrate and describe certain aspects, embodiments, and examples of the principles claimed below. It is not intended to be exhaustive or to limit the described principles to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. Such modifications are contemplated by the inventor and within the scope of the claims. The scope of the principles described is defined by the following claims. It will be understood that the figures and accompanying text are exemplary in nature, and not limiting. For example, a pre-combustion diesel fuel mixing device can be used in cooperation with any diesel engine, and is not limited to use with the engine  10  shown in  FIGS. 1-2 .