Abstract: A wind generating device employs modules each having two turbines. Each of the turbines employs two rotors coaxially aligned by a shaft associated with an in-line generator. Alternatively, the turbine employs only one rotor for low wind areas. The arrangement includes a proximal channel with a leading portion having decreasing radius toward the first rotor which acts as a collector and a following portion connecting fluidly the first and second rotor and a distal channel which is separate from the proximal channel and opens into the following portion thereby adding to the airflow to the second rotor. Downstream from the second rotor is a diffuser with a radius increasing with distance from the rotor. The modules may be stacked vertically stacked which allows for yaw responsive to wind. The modules may be mounted on a tower.

Abstract: A method and system improving energy efficiency of a turbojet engine by optimizing rotating speed of a fan and operability of an engine, by freeing the fan from exclusive control of a low-pressure (LP) shaft by providing combined control with a high-pressure (HP) shaft when cruising power has been reached. The turbojet engine include at least one LP turbine and one HP turbine coupled to coaxial LP shafts and HP shafts, respectively, which can drive LP and HP compressors, respectively. The LP compressors include a fan that forms a first primary air-intake compression stage. The LP and HP shafts are mounted on one of two driving mechanisms, an inner ring gear, and a planet carrier for a planetary gear train for driving the fan, the HP shaft being mounted on a disengagement mechanism and the fan being coupled to the planetary gear train via an outer driven ring gear.

Abstract: A fan cooling system has individual fan modules which are connected together in an end-to-end configuration, where one of the fan modules is connected to a mechanism which rotates the linear array of fan modules. The fan modules are substantially identical, which allows prefabrication of the fan modules prior to on-site installation of the system. Each fan module may contain water injection piping and nozzles, which allows the fan cooling system to dispense fog. The linear array of fan modules may be rotated along a longitudinal axis, such that the axial flow direction of the fans may be changed with respect to a vertical plane. A suggested use of the fan cooling system is for the cooling of livestock in large livestock structures.

Abstract: A gas turbine engine comprises a fan section including a fan hub supporting a plurality of fan blades for rotation relative to a fan case, a shaft rotatable relative to the fan case about an engine center axis, and a geared architecture driven by the shaft to provide driving output to rotate the fan hub. A compressor is positioned forward of the geared architecture and radially inward of the fan blades, with the compressor being driven by the shaft.

Abstract: A mounting apparatus for a fan includes a bracket, two fixing members, two screws, and a shield plate. The bracket includes a fixing plate defining a vent and two first through holes adjacent to opposite ends of a top of the vent. The screws extend through the fixing members and the first through holes of the bracket, in that order, for engaging in an upper portion of the fan arranged behind the fixing plate, with the vent aligning with the fan. A top of the shield plate is rotatably connected between the fixing members. The shield plate hangs vertically by gravity to cover the vent upon a condition that the gravity of the shield plate is not overcome by airflow passing through the vent.

Abstract: Provided is a motor device capable of suppressing undesired vibrations occurring at the time of starting a motor, by canceling a torque in a motor device system so as to reduce a reaction torque acting on a motor base. The motor device is equipped with a dual axis motor having first and second rotating shafts and projecting at either end, a rotational direction converter having an input shaft to which the torque of the dual axis motor is inputted and an output shaft that outputs the torque by rotating in a direction opposite to that of the input shaft, and a flywheel provided at an end portion of the first rotating shaft, for balancing out the reaction torque acting on the input shaft and the output shaft of the rotational direction converter when the dual axis motor rotates.

Abstract: A power steering pump and water pump assembly is disclosed. The assembly includes a power steering pump with a rotating shaft and a water pump. The water pump has a housing and a rotatable shaft for driving an impeller, which is mounted on an inner end of the shaft. An outer end of the water pump shaft engages the shaft of the power steering pump, and the power steering pump shaft drives the water pump shaft. The water pump may include a seal and a bearing having an inner race and outer race for supporting an outer end of the water pump shaft and cantilevering the shaft to support and journal the impeller. The shaft of the power steering pump may engage the shaft of the water pump through engagement of male and female torque transmitting profiles that axially slide together.

Abstract: A floating power generation assembly comprises at least three floating units (900) floating on a body of water, and at least three anchors (916) secured to a solid surface beneath the body of water, each of the floating units (900) being provided with a power generator, the floating units (900) being arranged substantially at the vertices of at least one equilateral triangle. Ship-borne apparatus for deploying the floating units of such a power generation assembly and a novel multiple wind turbine assembly are also described.

Abstract: A fan assembly includes a guide rail, a number of fan brackets slidably mounted to the guide rail, an air blocking member slidably mounted to the guide rail to fill a space between two fan brackets, and a number of fans correspondingly fixed to the fan brackets. To relocate the fans, the fan brackets and the air blocking members are slid out of the guide rail and are remounted to the guide rail in a different order.

Abstract: A rotor of a thermal fluid flow machine, especially a gas turbine, is provided. The rotor includes a plurality of rotor components that are held together by a common tie-bolt that extends through the center of the rotor components. The tie-bolt is fixed in at least one of the rotor components using at least one star spring that surrounds the tie-bolt in a circumferential direction.

Abstract: The ribbon drive generation apparatus is comprised of a ribbon-like curved shape, composed either of metal or other suitable material, attached to a containment tube, peripheral rings, shaft, or porous central tube, with the complete apparatus being contained in a tube having a constant diameter for the length of the tube. The ribbon can be peripherally mounted to the containment tube and optionally to a central porous tube. In this form the containment tube rotates and can form part of a rotor for a generator apparatus. The optional central porous tube can also be used as a bearing surface or, if attached to the inside edge of the ribbon, a power take-off shaft.

Abstract: A turbo-machine includes at least two rotors which are mounted so as to be rotatable in opposite directions relative to one another about a rotational axis and on which are arranged blades or vanes, having a rotatably mounted machine shaft and having a drive mechanism which connects the machine shaft to the at least two rotors and which converts a rotational movement of the machine shaft into rotational movements of the rotors in opposite directions relative to one another or vice versa. In at least one embodiment, the turbo-machine is designed to utilize the hydrodynamic advantages of counter-rotating rotors yet at the same time have comparatively low mechanical complexity and component density and therefore increased reliability.

Abstract: A turbomachine comprises a turbine shaft, first and second rotors, first and second propulsion stages, and a magnetic stator. The first rotor is rotationally coupled to the turbine shaft, and coaxially arranged along an axis. The first propulsion stage is rotationally coupled to the first rotor, opposite the turbine shaft. The second rotor is coaxially arranged about the first rotor, and the second propulsion stage is rotationally coupled to second rotor, opposite the turbine shaft and adjacent the first propulsion stage. The magnetic stator is coaxially arranged between the first rotor and the second rotor, forming a magnetic coupling between the and second rotors to drive the second propulsion stage in contra-rotation with respect to the first propulsion stage.

Abstract: A double-flow centrifugal pump is disclosed, in which, using an impeller, a fluid can be suctioned from two axial sides from a negative pressure area and can be delivered in the radial direction into a positive pressure area. The negative pressure area is sealed off with respect to the positive pressure area by at least one stationary pump component, for example the pump housing and/or an insert part. According to the invention, sealing gaps are formed as axial gaps arranged axially between the impeller and the pump component and extending in the circumferential direction and in the radial direction, wherein the gap width(s) of said axial gaps is less than the radial spacing (a) of the impeller from all the components arranged with a radial spacing from the impeller.

Abstract: A recirculation fan includes a casing, a covering member, and a fan assembly. The casing has a base. The covering member is coupled with the casing to define an accommodation space. The fan assembly is disposed within the accommodation space, and includes a first impeller, a second impeller, a motor, and a plurality of magnetic elements. The second impeller is located beside the first impeller. The motor is fixed on the base of the casing and connected with the first impeller for driving rotation of the first impeller. The magnetic elements are arranged between the first impeller and the second impeller. A wind force generated by the first impeller and a magnetic torque resulted from a magnetic vortex of the magnetic elements cause contactless rotation of the second impeller.

Abstract: A high efficiency, adaptive control, compound ducted wind turbine capable of providing higher efficiency in energy extraction from a fluid. Performance of efficiency expressed as coefficient of performance (Cp) in accordance with the Lanchester-Betz-Joukowski limits is sustainable and significantly higher than an un-ducted, mono-propeller wind turbine of comparable diameter.

Abstract: A water pump for a vehicle may include a water pump housing, a water pump drive shaft, a bearing, a first rotation plate connected to one end of the water pump drive shaft, a first magnet mounted on one surface of the first rotation plate, an impeller rotation shaft coaxially disposed with the water pump drive shaft, an impeller bearing rotatably enclosing an exterior circumference of the impeller rotation shaft, a second rotation plate connected to one end of the impeller bearing, a second magnet mounted on one surface of the second rotation plate, and an impeller connected to the other end of the impeller bearing, wherein the one surface of the first rotation plate and the one surface of the second rotation plate may be disposed apart from and face each other, and facing poles of the first and second magnets may be different from each other.

Abstract: A gas turbine rotor for a gas turbine is provided. The gas turbine rotor includes a compressor rotor shaft, a turbine rotor shaft and a coupling device frictionally connecting the two rotor shafts, wherein the coupling device is designed in such a way that the friction connection also exists when the two rotor shafts are displaced relative to one another. In this case, the turbine rotor shaft is lengthened at the end facing the compressor rotor shaft in such a way that said turbine rotor shaft overlaps with the compressor rotor shaft in the axial direction and the coupling device connects this lengthened end of the turbine shaft to the compressor rotor shaft in the radial direction.

Abstract: A cooling fan module includes a first cooling fan pivotally connected with a second cooling fan. The second cooling fan is rotatable relative to the first cooling fan between a first state and a second state. The second cooling fan is located on the first cooling fan in the first state. The second cooling fan is located at a lateral side of the first cooling fan in the second state.

Abstract: The invention provides a heat-dissipating system and a control method thereof. The heat-dissipating system has a plurality of fans and is configured for adjusting rotation-speeds of the fans. The control method includes following steps: obtaining a plurality of rotation-speed values of the fans; computing out a rotation-speed reference value according to the rotation-speed values; when the rotation-speed reference value is greater than a first threshold value, decreasing the rotation-speeds of the fans through a corresponding fan control signal; when the rotation-speed reference value is less than a second threshold value, increasing the rotation-speeds of the fans through the corresponding fan control signal.

Abstract: A machine train includes a drive unit, preferably a steam turbine with axial exhaust flow, a geared turbine machine, and an additional compressor. The geared turbine machine has an integrated gear train with a drive pinion for driving turbine machine rotors via a large gear, and an output pinion of a rotational speed reduction power gear for driving the additional compressor.

Abstract: The present invention is comprised of a wind powered energy amplification method and systems for capturing wind power and harvesting tangentially amplified energy. The harvested tangentially amplified energy is converted, processed and stored for use for generating continuous, on demand and stand by electricity to supply electricity. The present invention is further comprised of methods and systems for extracting, processing and storing water and carbon dioxide to supply water and supply carbon dioxide.

Abstract: A turbocharger with a high pressure (HP) and low pressure (LP) stage, designed such that swirl in a conduit providing fluid communication between the LP compressor outlet and the HP compressor inlet is received by the second stage compressor counter to the direction of rotation of the second stage compressor wheel. This is achieved without requiring vanes such as inlet guide vanes, and thus is highly efficient as well as free of blockage and excitation.

Abstract: A three journal bearing supported shaft with a link between two of the bearings may allow for longer spacing between the wheels supported by the shaft. The flexible shaft may move one bending critical speed below the minimum operating speed of the shaft and the next bending critical speed above the maximum operating speed of the shaft, thus extending the speed range significantly. A tie rod may be used as the link in the shaft.

Abstract: A power-generation system is provided. The system includes a plurality of vertical axis wind turbines (VAWTs). Each VAWT includes an upstanding support structure, a central shaft positioned along a central axis of the VAWT, a plurality of struts extending from the central shaft, and a plurality of blades, each blade positioned at an end of a corresponding strut and oriented substantially vertically. The VAWTs are grouped in sets that are arranged in rows, and are separated from each adjacent VAWT by a distance of approximately one rotor diameter.

Abstract: The ribbon drive generation apparatus is comprised of a ribbon-like curved shape, composed either of metal or other suitable material, attached to a containment tube, peripheral rings, shaft, or porous central tube, with the complete apparatus being contained in a tube having a constant diameter for the length of the tube. The ribbon can be peripherally mounted to the containment tube and optionally to a central porous tube. In this form the containment tube rotates and can form part of a rotor for a generator apparatus. The optional central porous tube can also be used as a bearing surface or, if attached to the inside edge of the ribbon, a power take-off shaft.

Abstract: The present invention provides a technology, which is capable of easily switching between the vacuum function and the blower function of the vacuum cleaner with a simple configuration, and is also capable of effectively utilizing the blower function even in the various situations. Typical air suction/injection device is configured that the interior of the main unit constitutes a main passage of air, and the interior of an injection passage section provided in the main body constitutes a sub-passage. Once a suctioned airstream is created in the main passage, a power fan inside of a suction chamber is rotated, and in conjunction with such a rotation, an injection fan is rotated so that an injecting airstream is created in the sub-passage. In such case, a passage switching section composed of a valve member provided in the location of joining the main passage and the sub-passage is switched to easily switch between a creation of an injecting airstream and a creation of a suctioned airstream.

Abstract: A multiple-motor blower includes a housing and a plurality of motors. The housing has a common outlet passage and different inlet passages. The motors are accommodated in the housing and respectively drive impellers to generate airflow flowing from the inlet passages to the outlet passage. Each of the impellers includes a hub and a plurality of blades mounted around a circumference of the hub. A ratio of a distance between adjacent two of the blades to a thickness of the blade in at least one of the impellers is smaller than or equal to 3.

Abstract: A supersonic compressor includes a fluid inlet, fluid outlet, and a fluid conduit extending therebetween with a supersonic compressor rotor disposed therein. The supersonic compressor rotor includes a first endwall and a plurality of vanes coupled thereto. Each pair of the vanes defines a fluid flow channel. The fluid flow channel defines a flow channel inlet opening and a flow channel outlet opening and includes a throat portion. The supersonic compressor rotor also includes a second endwall and at least one axially translatable fluid control device positioned adjacent to the rotor. The axially translatable fluid control device is configured to obstruct the throat portion and includes at least one axially translatable protrusion insertable into at least a portion of the throat portion.

Abstract: A fan assembly including a housing, a supporting member, a driving device and a passive impeller. The supporting member is disposed in the housing, and the driving device is disposed on the supporting member. The passive impeller includes a first hub and a plurality of first passive blades encircling the first hub. The active impeller includes a second hub and a plurality of active blades encircling the second hub and actuated to rotate by the driving device. In an axial direction, the first hub is disposed between the driving device and the second hub, and through rotation of the active impeller, airflow is produced which actuates the passive impeller to rotate.

Abstract: An axial-flow compressor has at least one stator vane row. At least one blade of the stator vane row is provided as a rotating unit (6), with the rotating unit being completely rotatable about a drive axis to act as a rotary compressor and with the drive axis being essentially vertical to a rotary axis of the axial-flow compressor.

Abstract: A header body for use in fluid circulation systems such as a hydronic heating system is provided in which the header body is configured to couple fluid flow to individual fluid circuits of the system. In one embodiment, the header body comprises a suction chamber with a fluid passage through which fluid flows as between one or more header bodies coupled together to form a manifold. A valve is disposed in the suction chamber, wherein in one example the valve comprises a valve body that is supported by portions of the suction chamber on opposite sides of the fluid passage. The valve body is configured with an aperture that is aligned with the fluid passage in a first and second operating state, one of which decouples the fluid circuit from the system.

Abstract: Operations of a turbine to generate energy from a relatively slow fluid flow, such as wind and water, are described. The turbine has a plurality of foils rotating about a central axis at a rotational velocity, each of the foils having a length and a foil axis parallel to the length and the central axis with each of the foils rotatable about its foil axis. From determinations of a velocity of the fluid flow, and angular location of each foil and the rotational velocity about the central axis, an attack angle of each foil is controlled with respect to the direction of fluid flow about the foil axis responsive to the velocity of the fluid flow, the angular location of the foil and the rotational velocity as the foil rotates about the central axis.

Abstract: A multi-inlet vacuum pump has a first pump device (10) and a second pump device (12). The first pump device (10) includes a first rotor element (18) having a plurality of first rotor discs (20, 21) arranged consecutively in the delivery direction (36). The second rotor disc includes a second rotor element (26) having a plurality of second rotor discs (28) arranged consecutively in the delivery direction (36). A first fluid flow (34) is suctioned through a main inlet (32) by the first pump device (10) and delivered in the direction of the second pump device (12). A second fluid flow (40) is suctioned through an intermediate inlet (38) by the second pump device and delivered in the direction of a pump outlet. The diameter of the last rotor disc (21) of the first pump (10) substantially corresponds to the diameter of the first rotor (28) of the second pump device (12).

Abstract: A blower includes a housing and a plurality of impellers. The impellers are disposed in the housing, and a mutual air-gathering passage is formed between the impellers and the housing. Compared to the prior art, the mutual air-gathering passage of the blower of the present invention can collect the airflow and stabilize the airflow. Thus, the air pressure at the air outlet is increased, and the overall airflow performance is improved.

Abstract: A turbine system is provided wherein during self-sealing operating conditions, excess leakoff steam is restricted from being dumped to a steam seal header and is diverted into the working steam flow path, hence increasing net output and efficiency for the turbine system. A related method is also provided.

Abstract: A fan assembly (20) used for dissipating heat from an electronic device. The fan assembly includes a bracket (30) and a fan module (40). The bracket has two parallel retaining walls (31). Each retaining wall defines an opening (311) and two recesses (313) at opposite sides of the opening. The fan module is received in the bracket. The fan module includes a fan (50) and a pair of clamping members (60). The fan has a pair of fan openings in alignment with the openings of the bracket for airflow flowing therethrough. The clamping members are respectively attached to opposite sides of the fan. A pair of resilient arms (67) extends out from each clamping member. Each resilient arm has an engaging portion (671) received in the corresponding recess of one of the retaining walls. The fan module is retained in the bracket via the engaging portions engaging with the recesses and being sandwiched between the retaining walls.

Abstract: A fluid turbine, comprising an inner shaft comprising a first number of concave vanes coupled thereto, the first number of concave vanes forming a number of rows of vanes, and an outer shaft, coaxial to the inner shaft, comprising a second number of concave vanes coupled thereto, the second number of concave vanes forming a number of rows of vanes in which adjacent rows of vanes alternate between the first number of vanes and the second number of vanes, in which the first number of vanes rotate axially in a first direction, in which the second number of vanes rotate axially in a second direction, and in which the concave surface of the first and second number of concave vanes define a fluid gathering surface.

Abstract: A wind-gas engine assembly and a motor vehicle with the same are provided. The wind-gas engine assembly comprises a high pressure gas engine (20) and a wind resistance engine (22) independent of each other. The high pressure gas engine generates primary power through injection of the high pressure gas. The wind resistance engine comprises an impeller chamber (221) and an impeller (222). The impeller chamber is provided with an air inlet (51) for receiving external wind resistance airflow, by which the impeller is driven to rotate to generate auxiliary power. The present invention not only utilizes wind resistance, but also saves energy and protects the environment.

Abstract: A wind turbine system utilizes three vertical shaft rotor units, each rotor unit consisting of three blades. The rotor units are synchronized such that the blades of each unit are maintained at twenty degree intervals, so as to capture head on wind at maximum efficiency. The front rotor unit comprises baffles which appropriately redirect airflow to the rotor units. A stabilizing fin is provided to ensure that the wind turbine system is always headed into the prevailing wind. The system achieves near one hundred percent efficient use of ongoing ambient wind.

Abstract: The vertical windmill includes a rotatable wind wheel column mounted to a base. The column includes a plurality of hollow wheel hubs stacked vertically atop each other. Each wheel hub includes a plurality of radiating mounting arms equidistantly spaced around the axis of the wheel hub such that the arms of an adjacent hub are angularly offset with respect to the other. A plurality of mounting assemblies is disposed on each of the mounting arms for mounting an array of wing blades. Each alternate stacked wheel hub and mounting arms together forms a wind wheel with vertically oriented wing blades mounted between upper and lower spaced arms such that the top wheel is interconnected with the lower wheel at a height less than the height of the blades. Each array of blades may freely rotate or be positively rotated to orient the blades for optimum usage of wind power in rotating the column.

Abstract: A mixer body has an interior bore and an exterior surface. The exterior surface has first and third stages and an intermediate second stage. The mixer body forms a support ring. The second stage has threads. The third stage has holes. Pins are secured to the support ring. A turbine is rotatably coupled to each pin. The disk has arcuate ends and cut away sections. A cylinder has first and third stages and an intermediate second stage. The cylinder has an input end with a large opening for receiving a pipe. The cylinder has an output end with a discharge opening. The second stage of the cylinder has threads coupled to the mixer body. The third stage of the cylinder supports the turbines and the disk. When the mixing body and cylinder are threaded together, they form a chamber.

Abstract: A casing provided centrally with a sealed structure chamber. Small-sized separate four filter elements are arranged each on opposite sides of the chamber such that inflow air from a suction section into the casing is introduced via the filter elements into the chamber. Each filter element is detachably fitted over a filter-element mount having openings at its outer periphery. Upon filter-element replacement, the filter elements are replaced individually by opening a window. An integral cast casing having compressing sections and compressed air passages integrally fabricated therewith by casting is formed with receptacles for first and second intercoolers and an aftercooler. The intercoolers and aftercooler are received in the receptacles. Outlets of the intercoolers are connected with suction sides of second- and third-stage compressors through second- and third-stage suction pipes, respectively. A blowoff silencer is arranged between the integral cast casing and an oil tank.

Abstract: An axial fan unit includes two or more impellers accommodated in a housing. Each impeller has a plurality of blades disposed about a center axis and is rotated by an associated motor. The rotation of the impellers creates a flow of air generally flowing along the center axis. A plurality of ribs are disposed between the impellers and connected to the housing. The ribs support an associated motor. At least one of an air-inlet side edge and an air-outlet side edge of each rib is inclined with respect to a direction that is perpendicular or substantially perpendicular to the center axis, such that it gets closer to one of an air-inlet side end and an air-outlet side end of the axial fan unit as it moves away from the center axis.

Abstract: A high-efficiency turbine generates energy from a fluid flow, such as wind or water currents. The turbine has a central axis with a plurality of foils rotatable about the central axis in a general paddlewheel arrangement. Each of the foils has a foil axis parallel to the length of the foil and the central axis, and is rotatable about its foil axis. During operation of the turbine, each foil assumes an attack angle to the direction of the fluid flow with the attack angle dynamically controlled about the foil axis as the foil rotates about the central axis so as to maximize the foil's moment about the central axis.

Abstract: A turbo-machine includes at least two rotors which are mounted so as to be rotatable in opposite directions relative to one another about a rotational axis and on which are arranged blades or vanes, having a rotatably mounted machine shaft and having a drive mechanism which connects the machine shaft to the at least two rotors and which converts a rotational movement of the machine shaft into rotational movements of the rotors in opposite directions relative to one another or vice versa. In at least one embodiment, the turbo-machine is designed to utilize the hydrodynamic advantages of counter-rotating rotors yet at the same time have comparatively low mechanical complexity and component density and therefore increased reliability.

Abstract: A cooling device, such as for cooling a chip and socket may have a centrifugal blower outside of a radial heatsink. In addition, supports for coupling the blower to a center motor may comprise overhead fan blades effectively creating a radial fan in series with the blower to maximize airflow and pressure capability and to minimize the noise. The vertical location of blower may further allow to improve motherboard component as well as system cooling all while reducing the vertical profile of the cooling device.

Abstract: Installing large-sized wind turbines creates numerous challenges and limitations, hindering acceptance of wind generated energy. With small-sized wind turbines, such hindrances are omitted or minimized. Sized ever smaller, more small-sized wind turbines may be installed per installation. Accordingly, a method and corresponding apparatus for maximizing wind energy gathering potential of a plurality of wind turbines, each wind turbine having a sweep height, for a given location is provided. The present invention includes sizing sweep heights of substantially all wind turbines of the plurality of wind turbines to intersect at least one horizontal plane unique from horizontal planes intersected by a sweep height of at least one immediately adjacent wind turbine.

Abstract: A fan module includes a framework and at least two blade assemblies arranged inside the framework. Each blade assembly includes at least two blade units arranged in line. The rotating direction of each blade assembly is opposite to that of adjacent blade assembly.

Abstract: A flow enhancement improvement for an underwater turbine generator (10) is disclosed wherein a longitudinal hole (240) is disposed in the central area (26), typically a hub (20) of the generator (10), and a second, augmentor duct (41), preferably rigid, is disposed about the outer duct (40) or housing of the unit to create a slot (200) area. The slot (200) and hollow hub (20) create areas of smooth, laminar fluid flow. The leading edges of the hub (20) or central ring and the augmentor (41) and outer ducts (40) are elliptical to enhance the fluid dynamics of the structure.