WO2000019082A9

WO2000019082A9 - Ramjet engine with axial air supply fan

Info

Publication number: WO2000019082A9
Application number: PCT/US1999/018745
Authority: WO
Inventors: Shawn P Lawlor
Original assignee: Ramgen Power Systems Inc; Shawn P Lawlor
Priority date: 1998-08-17
Filing date: 1999-08-17
Publication date: 2000-08-24
Also published as: AU2341200A; WO2000019082A2; WO2000019082A3

Abstract

An axial fan for a ramjet engine prime mover. A ramjet engine power generator is provided with supersonic ramjets at the distal ends of a low aerodynamic drag rotor. The rotor is affixed at a central hub to a shaft, and rotates about an axis defined by the shaft. An axial fan, with output longitudinally along the inlet side of said shaft, supplies inlet air to the ramjet engine. Efficient mixing of the oxidant and fuel prior to entry into the ramjet combustor, and the short residence times in the combustion chamber, minimize the formation of undesirable oxides of nitrogen.

Description

RAMJET ENGINE WITH AXIAL AIR SUPPLY FAN

This patent application claims priority from U.S.

Provisional Patent Application No. 60/096,831, filed August 17, 1998, and entitled RAMJET ENGINE WITH AXIAL

AIR SUPPLY FAN, the disclosure of which is incorporated herein by this reference.

A portion of the disclosure of this patent document contains material which is subject to copyright protection. The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and

Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

TECHNICAL FIELD

My invention relates to a high efficiency axial fan for the supply of air, and to the novel combination of such fan to a transversely disposed ramjet engine. More particularly, my invention relates to a power plant driven by a ramjet engine, and to a unique combination of inlet air supply components and ramjet power train components .

BACKGROUND

A continuing demand exists for a simple, highly efficient and inexpensive thermal power plant which can reliably provide low cost electrical and mechanical power. This is because many electrical and/or mechanical power plants could substantially benefit economically from a prime mover that offers significantly improved cycle efficiencies. This is particularly true m medium size power plants generally m the 10 to 100 megawatt range - which are used m many industrial applications, including stationary electric power generating units, rail locomotives, and marine power systems.

Medium sized power plants are also well suited for industrial and utility cogeneration facilities. Such facilities are increasingly employed to service thermal power needs while simultaneously generating electrical power m a cost effective manner. Power plant designs which are now commonly utilized m co-generation applications include (a) gas turbines, driven by the combustion of natural gas, fuel oil, or other fuels, which capture the thermal and kinetic energy from the combustion gases, (b) steam turbines, driven by the steam which is generated m boilers from the combustion of coal, fuel oil, natural gas, solid waste, or other fuels, and (c) large scale reciprocating engines, usually diesel cycle and typically fired with fuel oils. Of the currently available power plant technologies, diesel fueled reciprocating and advanced aerodeπvative gas turbine engines have the highest efficiency levels. Unfortunately, with respect to the reciprocating engines, at higher power output levels, the size of the individual engine components required become almost unmanageably large, and as a result, commercial use of single unit reciprocating engine systems m larger sizes has been minimal.

Gas turbines perform more reliably than reciprocating engines, and thus are m widespread use. However, because gas turbines are only moderately efficient m converting fuel to electrical energy, gas turbine powered plants are most effectively employed m co-generation systems where both electrical and thermal energy can be utilized. In that manner, the gas turbine efficiency can be counterbalanced by using the thermal energy to increase the overall cycle efficiency.

In any event, and particularly m view of reduced governmental regulation m the sale of electrical power, it can be appreciated that significant cost reduction m electrical power generation would be desirable. This objective can be most effectively accomplished by generating electrical power at higher overall cycle efficiency than is achieved with technology currently utilized for power generation.

One of the technical challenges m providing a high efficiency ramjet based engine is the ability to provide a uniform fuel air mixture, at near ambient pressure, at the ramjet inlet ramp compression structure. Incoming air must be received through an inlet structure, and thoroughly mixed with fuel, and then fed to the ramjet inlet, all in a manner which promotes good fuel/air mixing and efficient uptake at the ramjet inlet. Also, the fuel/airmix must be fed to the ramjet inlet in a stable, reliable smooth flow pattern, without short circuiting or unnecessary turbulence.

In gas turbine technology, it is well known that an axial bypass fan and an axial combustion air compressor are effective in an axially oriented combustion chamber arrangement, to drive post combustion turbine blades. However, my ramjet engine compresses essentially ambient pressure fuel/air mixtures against a stationary peripheral wall, and is thus oriented transversely to the output shaft . Since the necessary inlet air compression to support combustion in the ramjet occurs only along the inlet ramp of the ramjet, in my ramjet engine, it is unnecessary to additional energy for the compression of gaseous fuels, or of combustion air. However, it is necessary to provide a uniform, low pressure flow of combustion air along a converging annulus, in order to position a fuel/air mixture where it is readily captured and burned by a rotating ramjet engine. Therefore, it would be desirable to provide an axial fan arrangement in combination with a transversely oriented ramjet engine, so as to be able to take maximum advantage of the highly efficient ramjet engine operating cycle, while reliably and uniformly mixing low pressure fuel and the supplied inlet air to provide a uniform, consistent composition lean fuel-air mixture to the engine . SUMMARY OF THE INVENTION

I have now invented a novel, improved power plant which uses as one important component the novel combination of an axial fan supply for combustion air at relatively low velocity to a supersonic ramjet prime mover which rotates a driven power shaft. By use of such an arrangement, efficient fuel air pre-mix can be achieved. Also, by use of a metered fuel feed apparatus, the power output of the ramjet power plant can be turned down as necessary to maintain the desired rotating velocity. In this manner, a constant rotating velocity can be achieved, as is necessary m synchronous power generation apparatus.

To achieve the desired power plant operational parameters, I have now developed a novel fuel -air mixing housing which uses an axial supply fan design and which introduces a lean, uniformly mixed fuel-air mixture to a transverse mounted ramjet engine configuration. This apparatus overcomes some specific problems inherent m the heretofore known apparatus and methods that are known to me and which have heretofore been proposed for the application of ramjet technology to stationary power generation equipment. Of primary importance, I have now developed a simple, low speed, essentially ambient pressure air supply axial fan apparatus which can deliver a stabilized, smoothly flowing oxidant carrier gas to a housing for thorough mixing with a gaseous fuel which is supplied at low pressure.

More specifically, my novel axial fan enables fuel- air pre-mix between an inlet carrier gas such as air which carries an oxidant such as oxygen, and thoroughly mixes the carrier gas with a selected fuel such as natural gas. The housing, and the process employed therein, thoroughly mixes the fuel and the oxidant to produce a fuel -oxidant of uniform mixture. Overall, the housing provides a convergent, preferably annularly shaped gas flow path, that is, of lower cross-sectional area toward the outlet as compared to the inlet of a section examined. Preferably, an annular housing is sized to match the output of the axial fan, and the fuel/air pre-mix feed requirements at the inlet of the transversely mounted ramjet engine. In my axial fan design, the inlet gas flow path m the fuel -air pre-mix housing has a longitudinal axis. The gas flow path is defined by d) an upstream housing end, (n) a downstream housing end, (m) an outer surface of an inner wall, and (IV) an inner surface of an outer wall. A plurality of fuel supply structures are disposed m fluid communication with the gas flow discharged from the axial fan. Most preferably, the fuel supply structures are mounted radially in spokelike fashion spanning all or a portion of the gap between the outer surface of the inner wall and the inner surface of the outer wall. For effective air flow stabilization, the number of fuel supply structures (stators) must be commensurate with the geometry involved in view of the fuel/oxidant mixing criteria desired. However, for one configuration depicted herein, where the annular inlet duct has diameter at the inner surface of the outer wall of about 72 inches, and a diameter at the outer surface of the inner wall of about 48 inches, the number of fuel supply structures (stators) is preferably up to about 30 or so. Also, each stator preferably spans a substantial portion of the gap, or more preferably extend fully between the gap between the outer surface of the inner wall and the inner surface of the outer wall, so that the output of the axial fan is flow stabilized.

A thoroughly mixed lean fuel-air mixture is supplied to the inlet of two or more transversely mounted ramjets. The ramjets are preferably provided in an unshrouded construction. Each ramjet is situated so as to engage and to compress the mixed inlet gas stream which is impinged by the ramjet inlet upon its rotation about the aforementioned axis of rotation. Combustion of well mixed fuel occurs in the rotary ramjet combustor. The hot combustion gases formed by oxidation of the fuel escape rearwardly from the ramjet nozzle, thrusting the ramjet tangentially about the axis of rotation, i.e., it rotates the rotor and associated output shaft . The power generated by the turning output shaft portions may be used directly m mechanical form, or may be used to drive an electrical generator and thus generate electricity. By use of my novel axial fan m combination with a transversely mounted ramjet which compresses a fuel/air mixture against a stationary peripheral wall, desired low emission levels of oxides of nitrogen can be achieved, and overall efficiency of the engine is enhanced.

The design of my axial fan overcomes some of the significant and serious problems which have plagued earlier attempts at the use of supersonic ramjets for efficient electrical power production.

First, careful attention to the aerodynamic design of axial fan blades and stators minimizes aerodynamic drag. Thus, the design minimizes parasitic losses to the power plant due to the drag resulting from power required to supply combustion air. Although a relatively small savings due to this element is achieved m the overall plant energy balance, it is nevertheless important commercially because it enables a power plant to reduce parasitic losses that undesirably consume fuel and reduce overall efficiency.

Second, the selection of materials and the mechanical design of rotating fan components avoids use of excessive quantities or weights of materials, and provides the necessary strength, particularly tensile strength where needed m the fan rotor. Third, the axial fan with annular air flow outlet is a key element m my system configuration which provides for effective mechanical separation of the cool entering fuel and oxidizer gases from the exiting hot combustion gases, while allowing supersonic ramjet operation along a transverse circumferential pathway.

To help achieve the desired power plant operational efficiency, I have now developed a novel axial fan design and overall engine configuration which overcomes some specific problems inherent m the heretofore known apparatus and methods that are known to me and which have been proposed for the application of ramjet technology to stationary power generation equipment. Of primary importance, I have now developed a simple, low speed axial fan apparatus which can deliver a stabilized, smoothly flowing air supply.

An airtight casing having an interior stationary housing with a first wall surface and an exterior stationary housing with a second wall surface are disposed substantially concentrically along an longitudinal axis, to define between the first wall surface and the second wall surface an annular inlet air plenum. Extending substantially radially between the first wall surface of the interior stationary plenum, and the second wall surface of the exterior stationary plenum, is a number Z of smooth, airfoil shaped stators S, where Z is a positive integer. A short distance therefrom, in an upstream direction, a centrally disposed fan rotor is provided to rotate about said longitudinal axis. The fan rotor is provided with a relatively smooth, bulbous stationary inlet nacelle, or alternately, a rotating inlet spinner. Just downstream of the inlet nacelle, the fan rotor has a generally cylindrical hub surface which provides a blade attachment portion. Extending substantially radially outward from the blade attachment portion are a number of fan blades. The fan blades are disposed to move air from upstream of the fan toward the airfoil shaped stators, and then on through the gap between the interior stationary plenum and the exterior stationary plenum.

A ramjet engine rotor operating cavity is provided, at least part of which has a lowered atmospheric pressure, in order to eliminate aerodynamic drag on the rotor. Attached at the radial end of the rotor are one or more of the at least one ramjets. Each of the ramjet engines is provided in an unshrouded thrust module configuration, where compression is accomplished against a peripheral radial wall. The ramjet engines are situated so as to engage and to compress that portion of the airstream which is impinged by the ramjet upon its rotation about the aforementioned axis of rotation.

Fuel is added to the inlet air before compression m the ramjet inlet. The fuel may be conveniently provided through use of fuel supply passageways located m airfoil shaped stators of the axial inlet air fan, which are located radially m an annular ring, with fuel injection passageways communicating between the fuel supply passageways and the inlet air passageway. Fuel injected into the inlet air stream is thus well mixed with the inlet air before arriving at the ramjet engine combustion chamber.

Many variations m the air flow configuration and m provision of the fuel supply, secondary fuel supply, may be made by those skilled m the art without departing from the teachings hereof. Finally, m addition to the foregoing, my novel combination of an axial fan and a ramjet power plant is simple, durable, and relatively inexpensive to manufacture.

OBJECTS, ADVANTAGES, AND FEATURES OF THE INVENTION

From the foregoing, it will be apparent to the reader that one important and primary object of the present invention resides m the provision of a novel combination of an axial air supply fan and a transversely mounted ramjet powered engine.

Other important but more specific objects of the invention reside m the provision of ramjet based power generation plant as described m the preceding paragraph which: allow the supply of combustion air to be done m a simple, direct manner; cooperate with the fuel supply structures to optimize fuel/air mixing; have a minimum of mechanical parts; are easy to construct, to start, to operate, and to service; cleanly burns fossil fuels; m conjunction with the just mentioned object, results in fewer negative environmental impacts than most power generation facilities presently m use.

Again, the important and unique feature of my ramjet engine is the combination of an axial flow inlet air fan with a rotating ramjet wherein the actual ramjet inlet is transverse to the axis of inlet air flow.

Other important objects, features, and additional advantages of my invention will become apparent to those skilled m the art from the foregoing and from the detailed description which follows and the appended claims, m conjunction with the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 provides a partial perspective view of my novel power plant apparatus, showing the inlet nacelle, the axial inlet air fan, the fuel header and inlet fuel feed lines which feed fuel at low pressure to stators for injection at fuel outlets, and showing the converging annular inlet gas flow path to accelerate the mixed inlet gas to the transversely oriented rotary ramjet, which rotates within a low aerodynamic drag housing and which compresses the mixed inlet gas against a peripheral wall, to oxidize the fuel and to create hot combustion gases, thereby driving the rotary ramjet and output shaft which is coupled with a gear box for useful mechanical output work. FIG. 2 is a partial perspective view of my novel power plant apparatus, similar to the view just shown in FIG. 1 above, but now showing the axial inlet air fan and accompanying fan motor in more detail, and now showing the fuel -air pre-mix housing having a series of radially disposed airfoil shaped stators and accompanying vortex generators for adding transverse momentum to the entering air to assure adequate mixing of fuel and air to produce a uniformly mixed inlet gas for supply to the transversely oriented rotary ramjet. FIG. 3 is a split, partially exposed perspective view of the combustion air inlet, showing the inlet nacelle, the axial inlet air fan, struts used for the connection of a portion of the electrical power, water, oil, compressed air, and vacuum lines to the engine.

FIG. 4 is a partially, split, partially exposed perspective view of my ramjet power plant apparatus, showing in a first part the annular air supply plenum and accompanying axial inlet air fan, and in a second part the fuel -air premix housing with airfoil shaped stators which are fixed between inner and outer stationary housing walls, and the vortex generators for adding transverse momentum to the entering air to assure adequate mixing of fuel and air to produce a uniformly mixed inlet gas for supply to the rotary ramjet.

FIG. 5 is a cross-sectional view of the inlet to my ramjet power plant, showing the inlet nacelle, the axial inlet fan and accompanying fan motor, the air supply plenum, the fuel -air premix housing with airfoil shaped stators which are fixed between inner and outer stationary housing walls, and the transition section with a converging annular passageway having an outer peripheral wall, for feed of the mixed inlet gas to the ramjets at the periphery of the rotor; cooling air, cooling water, and the air lines helpful to evacuate boundary layer air from the rotor to help assist in reduction of aerodynamic drag near the rotor are also illustrated. DETAILED DESCRIPTION

Referring now to the drawing, FIG. 1 depicts a partial cut-away perspective view of my novel rotary ramjet driven power plant 100. Major components shown in this FIG. 1 include the rotary ramjet engine assembly 102 and gear set 104. The ramjet engine assembly 102 has a driven output shaft 108, which is operationally coupled with gear set 104 for power transfer therethrough. Gear set 104 has power output shaft 110, which is coupled with and rotates at a desired rate of rotation to drive an electrical generator (not shown) , or other shaft power consumer.

The structure of the rotary ramjet engine assembly 102 has several key components. A high strength rotor 120_s has output shaft portions 124 and 108. The output shaft portions 108 and 124 turn in inlet 126 and outlet (barely visible) 128 bearing assemblies, respectively. In FIG. 1, one embodiment of my high strength rotor 120 design and components thereof is shown, illustrating rotor construction using central disc 134 (of ultra-high strength steel, or high strength fiber composite, or metal matrix composite) .

A plurality of rim segments 138 in a series of rim segments from 138η_ through 138_X are interlockingly and detachably secured to the central disc 134. One or more, and preferably two or more ramjets 140 are provided using detachably affixable ramjet thrust segments 142 in a series of thrust segments 142 η_ through 142_x affixed to central disc 134. Each of the required ramjet thrust segments are provided in functional order, shaped as required in a then relevant portion of the applicable ramjet structure, the basics of which are taught in my earlier and now issued United States Patent No. 5,372,005, and particularly, No. 5,709,076, as well as U.S. Patent Application Serial No. 08/213,217 (filed March 3, 1994); for details see the full disclosures of each, which are incorporated herein in their entirety by this reference.

Importantly, there are also a number of peripherially extending and preferably helical strakes S]_ through S^. Each of strakes S_]_ through S^ has a number of strake segments SS of radial height Sj-j- each strake segment SS being integrally provided with a rim segment 138, or with a ramjet thrust segment portion 142, as appropriate. The strakes Sη_ through SJJ partition the well mixed fuel-air inlet gas 170 (which preferably is thoroughly and uniformly mixed as further explained herein below to provide both fuel and oxidizer) , so that the mixed inlet gas 170 flows to the ramjet inlet throat 174. This process occurs at a first of one or more ramjets 140 and then at a second (not shown) of one or more ramjets 140 and so on to an Xth of the one or more ramjets 140 that are mounted on rotor 120. Preferably, the number X of ramjets 140 and the number N of strakes S are the same positive integer number, and N and X are at least equal to two.

The strakes S]_ through SJJ allow the feed of a well mixed fuel-air inlet gas 170 to each ramjet 140 without appreciable bypass of the entering mixed inlet gas 170 to the exhaust combustion gases 176. Also, the exhaust combustion gases 176 exiting from each of the one or more ramjets 140 is effectively prevented by the arrangement of strakes S from interfering with the inflow of fuel air premix, thus effectively preventing the return of spent combustion gases 176 from the exhaust side S^x of strakes S to the inlet side SJ_N °f strakes S .

The construction and operation of my ramjet 140 is quite unique. The ramjet thrust segments 142, as seen in FIG. 1, are provided in an unshrouded configuration, that is, the ramjet structure affixed as part of rotor 120 provides the necessary elements for compression of incoming mixed inlet gas 170, except for a containment structure against which compression of the mixed inlet gas 170 and expansion of escaping hot combustion gas 176 occurs. In this unique engine, the necessary containment structure for compression of the incoming fuel -air mixture is provided by the inner peripheral wall 203 of engine housing 204. The above discussed strakes S have a radial height S_jj (see FIG. 5) which extends to a tip end S^ that is designed for rotation very near to the interior peripheral wall surface 203, in order to minimize gas leakage in either direction.

Turning now to FIGS. 4 and 5, the detailed structure of the overall fuel -air pre-mixing housing 210 and related components of my novel rotary ramjet power plant 100 are illustrated. Major components include an inlet plenum 212, a support casing 214 with utility struts 216 that support fan housing 218, and the mixing section 220. The preferably smooth outer surface 222 of the fan housing 218, and the inner surface 224 of the support casing 214 provide an initial length Xp for receiving the inlet airflow.

As noted in FIG. 2, a fuel FF such as natural gas is supplied, through a main fuel header 226 and a pressure regulator 228, thence to fuel supply line 230 and then on to one or more fuel supply headers or manifolds 232. Fuel distribution lines 234 (in a series of distribution lines 234]_ through 234_x, where "x" associated with distribution lines "234" corresponds to the number of fuel supply structures 240 (stators) , to provide fuel from headers 232 to the fuel supply structures 240, via fuel inlet fittings 242 (see FIG. 7) .

Fuel inlet fittings 242 are preferably provided in size and shape to extend through outer wall 250 of mixing section 220, to secure (with fasteners such as nuts 251) the radially distal fuel inlet 252 of fuel supply structures 240. The fuel inlet fittings 242 can also be utilized to secure the radially distal or outer end 240Q of fuel supply structures 240 to the inner surface 255 of outer wall 250. In this configuration, a radially proximal inlet 256 with proximal inlet threads 257 is plugged with gas tight fastener 258, which also serves to secure the radially proximal or inner end 240 of fuel supply structures 240 to the outer surface 260 of inner wall 262 of the convergent, preferably annular inlet air plenum 264. As further seen in FIG. 3, spacers 266 with smooth airfoil leading edges 268 are provided at a narrow cross-section of inlet air plenum 264 to securely space apart the inner wall 262 and outer wall 250 via a gap distance G. Fuel supply structure 240 preferably has a low drag aerodynamic body shape with a leading edge 240j_., a trailing edge 240^. a chord C and a thickness T. A fuel passageway 270 defined by interior wall 272 extends between distal inlet 252 and the proximal inlet 256 of fuel supply structure 240. For ease of fabrication, I prefer to provide fuel injection outlets 274 defined by an injector edge wall in opposition to fastener receiving threads which are used to secure one or more vortex generators 278 to stator 240 via fasteners 280. As noted above, ramjets 140 are suitable for oxidizing a fuel FF continuously supplied thereto, preferably in a thoroughly mixed inlet gas stream 170. Referring now to FIG. 4, and to FIG. 1, it can be seen that in order to accomplish the required thorough mixing, the entering airstream 288 is preferably provided through inlet plenum 212, where the preferably stationary inlet nacelle 292 before axial fan 300 partitions the inlet carrier gas stream 288 (normally air, although mixed gas containing preselected additives could be provided) into an annular air supply stream 294. The aerodynamically efficient blades 301 of axial fan 300 are attached to fan hub 302 which is driven by fan motor 304. Fan motor 304 is supported by preferably spoked 305 type mounting bracket 306 detachably mounted from a recessed fan mounting flange 308 at the upstream end 310 of support casing 214. The fan is preferably supplied by electrical power via cable 320, through utility strut 216.

The annular flow of the inlet air stream 294 is straightened and smoothed by the leading edge portion 240L of the fuel supply structures 240. Fuel is injected at fuel injection outlets 274. Transverse momentum is imparted to some of the inlet air stream 294 as well as to the relatively low velocity injected fuel by vortex generators 278. The vortex generators are located sufficiently upstream of the ramjets U so as to allow thorough and reliable fuel-air mixing through a mixing length Xrø, as indicated in FIG. 9. A resultant thoroughly mixed inlet gas stream 170 is fed to ramjets 140, which utilize oxygen (preferably from the incoming airstream 288, or otherwise supplied or supplemented) as the oxidant source. Ramjets 140 are provided at the outer, distal reaches of rotor 120 so that the propulsive effect of the ramjets 140 is utilized to turn rotor 120 and the output shaft 108.

The rotor 120 is rotatably secured in an operating position by a fixed support structure base 320 at pivot pin 322 in a manner suitable for extremely high speed operation, such as rotation rates in the range from as low as about 4,500 rpm, or more preferably from about 6000 to 7000 rpm, or up to about 8,900 rpm, or even 10,000 to 20,000 rpm, or higher. In this regard, inlet side bearing assembly 126 and outlet side bearing assembly 128, or suitable variations thereof, must provide adequate bearing support for high speed rotation and thrust, with minimum friction. The detailed bearing and lubrication systems may be provided by any convenient means, and although oil supply and return lines are shown in FIG. 5 of the drawing, need not be further discussed herein.

As earlier indicated, a key feature of my power plant is the rotor 120. Rotor 120 spins about its axis of rotation due to thrust from ramjets 140. Two design parameters of the rotor 120 are extremely important. First, the rotor must be constructed of materials which enable it to survive the extremely high centrifugal loads encountered while the rotor is moving so that the ramjet can operate at supersonic speeds, preferably in the Mach 3.5 range, i.e., the rotor must be capable of withstanding extremely high tensile stress. Second, at such speeds, minimizing the rotor's overall aerodynamic drag is critical.

For ease of construction, I prefer to use an interlocking dove tail type attachment arrangement for interlocking the ventilatable rim segments 138 to rotor hub 134. As provided, any of the rim sigments 138 or the ramjet thrust modules such as module 142 are releasably affixed as a part of rotor 120, and thus rim segments 138 and the ramjet thrust modules may be easily replaced. I prefer use of a boundary layer control technique to reduce aerodynamic drag on the rotor 120. One suitable method is to provide a tight fitting housing 400 with rotor side surface 402 in close proximity to surface 120_s of rotor 120. More preferably, providing and sealing an operating cavity 404, behind the tight fitting housing 400, so as to enable the rotor to function as a vacuum pump, which allows most gas on the surface 120_S of the rotor to be suctioned off via vacuum line 410 from hoop shaped vacuum header 412. Also, cooling air for the rim segments 138 and thrust segments 142 is provided via hoop shaped compressed air header 420 and air line 422. Finally, even though high combustion temperatures are experienced, my advanced fuel -air mixing apparatus provides extremely low NOX output. This is because of the lean and extremely well mixed fuel -air inlet gas stream, and because of the short residence times at the high combustion temperatures.

One important advantage which is afforded by my axial air flow fan and accompanying fuel -air mixing apparatus and method is that low pressure fuel can be utilized, particularly fuels of less than 60 psig, and more preferably less than about 30 psig, and even more preferably, of about 15 psig or less. A related advantage is that low pressure gas gathered from hydrocarbon production can be utilized. For example, gas now normally flared in offshore oil platforms, or from gas gathering fields, or gas transmission facilities, or from refinery operations, can be advantageously utilized, without the necessity to compress such gas

(which operation cannot be conducted safely, with respect to some types of fuels which may be alternately and advantageously consumed in my equipment) .

Thus, it can be seen that the method and apparatus for producing mechanical, electrical, and thermal power as described above provides a revolutionary, compact, easily constructed, cost effective power plant. The output from this power plant can be used in conjunction with existing power delivery systems, and represents a significant option for reducing air emissions by combustion of clean burning fuels. Further, given the efficiencies, dramatically less fuel will be consumed per unit of electrical, mechanical, or thermal energy generated.

Consequently, it will be seen that the objects set forth above, including those made apparent from the proceeding description, are efficiently attained, and, since certain changes may be made in carrying out the construction of a power generation apparatus and in the execution of the method of power generation described herein, while nevertheless achieving desirable results in accord with the principles generally set forth herein, it is to be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For example, while I have set forth exemplary designs for a fuel feed arrangement, many other embodiments are also feasible to attain the result of the principles of the apparatus and via use of the methods disclosed herein.

All the features disclosed in this specification (including any accompanying claims, the drawing, and the abstract) and/or any steps in the method or process so disclosed, may be combined in any combination, except combinations where at least some of the features and/or steps are mutually exclusive. Each feature disclosed in this specification (including in the accompanying claims, the drawing, and the abstract) , may be replaced by alternative features serving the same or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Therefore, it will be understood that the foregoing description of representative embodiments of the invention have been presented only for purposes of illustration and for providing an understanding of the invention, and it is not intended to be exhaustive or restrictive, or to limit the invention to the precise forms disclosed. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as expressed herein. As such, it is intended to cover the structures and methods described therein, and not only the equivalents or structural equivalents thereof, but also equivalent structures or methods. Thus, the scope of the invention is intended to include variations from the embodiments provided which are nevertheless described by the broad meaning and range properly afforded to the language used herein, or to the equivalents thereof.

Claims

1. Apparatus for generation of power, said apparatus comprising : (a) a housing, said housing extending along a longitudinal axis, said housing comprising

(i) an air inlet for intake of combustion air, said air inlet having (A) an outer wall with an inner surface, and (B) an inner wall with an outer surface, said outer wall and said inner wall forming an annular inlet air plenum therebetween, and (ii) and an exhaust gas outlet; (b) a fuel inlet for supply of fuel to said apparatus ; (c) an inlet fan, said inlet fan axially oriented with respect to said longitudinal axis of said housing, said inlet fan comprising (i) a hub

(ii) a plurality of rotating fan blades disposed in a c i r cumf er ent i al ly spaced apart relationship and extending substantially radially outward from said hub, said fan blades adapted to engage and ambient airstream and urge the same long said longitudinal axis, and (d) on or more stators, at least one of said one or more stators comprising a low drag airfoil shape, at least one of said one or more stators (i) extending substantially radially between said inner surface of said outer wall and said outer surface of said inner wall, and

(i) further comprising fuel injection outlets for injecting fuel supplied thereto into said inlet air plenum;

(e) a rotor, said rotor rotatably secured along an axis of rotation, said axis of rotation parallel to said longitudinal axis of said housing, said rotor extending outwardly from said axis of rotation to an outer surface portion;

(f) a peripheral wall, said peripheral wall

(i) positioned along said axis of rotation between said combustion air inlet and said exhaust gas outlet,

(ii) positioned radially outward from said axis of rotation,

(iii) positioned radially outward from said outer surface portion of said rotor, and (iv) comprising an inner peripheral wall surface portion;

(g) one or more ramjets, said one or more ramjets

(i) each comprising an unshrouded compression portion located at said outer surface portion of said rotor,

(ii) said unshrouded compression portion cooperating with at least a portion of said inner peripheral wall surface portion to compress said inlet combustion air between said one or more ramjets and said at least a portion of said inner peripheral wall surface portion, (iii) operable at a speed, with respect to said inlet air, of at least Mach 1.5;

(h) one or more strakes, each of said one or more strakes provided for each of said one or more ramjets, wherein each of said one or more strakes extends substantially radially outward from at least a portion of said outer surface portion of said rotor to a point adjacent said interior peripheral wall surface portion, said one or more strakes effectively separating said inlet combustion air from said exhaust gases when said one or more ramjets receive inlet air and fuel thereto and oxidize said fuel to create hot combustion gases which propulsively exit from said one or more ramjets to create a thrust force causing rotation of said rotor.

2. The apparatus as set forth in claim 1, wherein said axial fan further comprises a fan motor, and wherein said fan motor is affixed to said inner housing.

3. The apparatus as set forth in claim 1, wherein in said inner housing further comprises a recessed fan mounting flange.

4. The apparatus as set forth in claim 3, further comprising a spoked fan mounting bracket, said spoked fan mounting bracket detachably affixed to said recessed fan mounting flange.

5. The apparatus as set forth in claim 2, wherein said fan motor is electrically powered.

6. The apparatus as set forth in claim 5, further comprising an airfoil shaped utility strut extending between said inner housing and said outer housing, and wherein electrical power for said fan motor is supplied through said utility strut.

7. The apparatus as set forth in claim 1, wherein said fan blades comprise aerodynamically efficient blade design.

8. The apparatus as set forth in claim 1, wherein each of said one or more strakes comprises a helical structure extending substantially radially from said outer surface portion of said rotor.

9. The apparatus as set forth in claim 2 , wherein the number N of said one or more helical strakes is equal to the number N of said one or more ramjets.

10. An apparatus for generating power, comprising:

(a) a support structure, said support structure comprising

(i) an oxidant supply conduit, said oxidant supply conduit including an axial supply fan, and

(ii) a first housing portion with a rotor side surface, and

(iii) a second housing portion with a rotor side surface ; (b) a first output shaft, said first output shaft rotatably secured with respect to said support structure;

(c) a rotor, said rotor comprising an outer surface portion, (d) one or more ramjet thrust modules, said one or more ramjet thrust modules

(i) each integrally provided with said outer surface portion of said rotor for rotation therewith,

(ii) each further comprise an unshrouded external portion, said unshrouded external portion comprising a substantially constant cross - sect ional size when sequentially examined in cross-section perpendicular to the axis of an inlet airflow from a forward cross- section to a rearward cross-section, to thereby minimize pressure drag when said one or more ramjet thrust modules operate at an inlet airflow velocity M_Q of at least Mach 1.5, and (iii) each cooperating with at least a portion of said rotor side surface of said second housing portion, to compress said inlet combustion air between said one or more ramjets and said at least a portion of said rotor side surface;

(e) one or more strakes, each of said one or more strakes provided for each of said one or more ramjet thrust modules, wherein each of said one or more strakes extends substantially radially outward from at least a portion of said outer surface portion of said rotor to a point adjacent said rotor side surface, said one or more strakes effectively separating said inlet combustion air from said exhaust gases when said one or more ramjets receive inlet air and fuel thereto and oxidize said fuel to create hot combustion gases which propulsively exit from said one or more ramjets to create a thrust force causing rotation of said rotor.

11. An apparatus for generating power as set forth in claim 1, or claim 10, wherein said at least one ramjet operates at an inlet velocity M_Q of between about Mach 1.5 and Mach 2.0.

12. An apparatus for generating power as set forth in claim 1, or claim 10, wherein said at least one ramjet operates at an inlet velocity Mg of at least Mach 2.0.

13. An apparatus for generating power as set forth in claim 1, or claim 10, wherein said at least one ramjet operates at an inlet velocity M₀ of at least Mach 2.5.

14. An apparatus _ for generating power as set forth in claim 1, or claim 10, wherein said at least one ramjet operates at an inlet velocity M_Q of at least Mach 3.0.

15. An apparatus for generating power as set forth in claim 1, or claim 10 wherein said at least one ramjet operates at an inlet velocity M_Q between Mach 3.0 and Mach 4.5.

16. An apparatus for generating power as set forth in claim 1, or claim 10, wherein said at least one ramjet operates at inlet velocity M_Q of approximately Mach 3.5.

17. The apparatus of claim 1, or claim 10, wherein said rotor comprises at least one central disc.

18. The apparatus of claim 1, or of claim 10, wherein said rotor comprises a metal matrix composite.

19. The apparatus of claim 18, wherein said metal matrix composite comprises titanium.

20. The apparatus of claim 17, wherein said at least one central disc comprises an ultra-high strength steel.