104 results about "Nozzle throat" patented technology

The embodiment of the invention discloses an ultrahigh compression ratio adjustable ejector and a variable working condition performance optimization design method thereof. The adjustable ejector comprises a nozzle, an adjusting cone, a suction chamber, a mixing chamber and a diffusion chamber, wherein working fluid is introduced into the nozzle, the adjusting cone is arranged at the throat part of the nozzle, and the fluid to be ejected is introduced into the suction chamber; the adjusting cone is formed by alternately and repeatedly connecting cylindrical surface sections and conical surface sections, and the adjusting cone can axially move; the method comprises the steps that the pressure of working fluid input into the adjustable ejector is monitored; when the pressure of the working fluid is changed between the first pressure and the second pressure, the adjusting cone is axially moved, and each cylindrical surface section directly faces the throat part in sequence, so that step type adjustment of the pressure of the working fluid is realized; when the pressure of the working fluid is changed between the second pressure and the fourth pressure, the adjusting cone is axially moved, and each conical surface section directly faces the throat part in sequence, so that the continuous adjustment of the pressure of the working fluid is realized; the mass flow of the ejected fluid in the adjustable ejector belongs to a preset range; the first pressure, the second pressure, the third pressure and the fourth pressure are gradually increased in sequence.

The invention discloses a sealing device for a jet pipe of a solid rocket engine. The sealing device comprises a front supporting body, a rear supporting cylinder and a sealing plug cover. The front section of the front supporting body is a circular-truncated-cone-shaped positioning cylinder, the rear section of the front supporting body is a circular-ring-shaped connecting cylinder, and internal threads are machined on the rear section of the inner wall of the circular-ring-shaped connecting cylinder. An external thread is machined on the outer wall of the rear supporting cylinder, a positioning circular plate is vertically fixed to the rear end of the rear supporting cylinder, and the outer edge of the positioning circular plate is machined to be a circular truncated cone face. The front supporting body and the rear supporting cylinder are inserted inwards from the two ends of the spray pipe respectively and then are in threaded butt joint, the outer wall of the front supporting body is tightly attached to the inner wall of a convergence section of the spray pipe and the inner wall of a spray throat, and the outer edge of a positioning circular plate of the rear supporting cylinder is tightly attached to the inner wall of an expansion section of the spray pipe. And the sealing blanking cap is in threaded connection with the front end of the rear supporting cylinder. According to the spray pipe sealing device, ignition pressure can be reliably established, and residues are few during separation.

A fluid inhalation device, comprises a casing having therein a fluid reservoir, a fluid-air outlet connected to a top end of the fluid reservoir, a vacuum channel, having a bottom end connected to a bottom end of the fluid reservoir, an air duct, having an air inlet at a first air duct end, and a nozzle connected to a second air duct end through a nozzle throat, and connected to the fluid reservoir through a nozzle exit. The nozzle throat is narrower than the nozzle exit, and a top end of the vacuum channel is connected to the nozzle.

The invention discloses an interference type focusing sensing probe based on an optical fiber built-in groove light splitting structure, an optical fiber groove structure is adopted in an optical fiber displacement sensing probe, so that reference light and measuring light are formed, the light path layout is optimized, the light collecting angle is increased, the contrast ratio of interference fringes and the signal-to-noise ratio of signals are improved, and the interference type focusing sensing probe has a wide application prospect. The design can effectively measure the complex morphology in the aero-engine part, has the characteristics of compact structure, small size, high measurement precision and the like, and can meet the test requirements of narrow and complex spaces such as an engine nozzle throat part and the like.

The present invention relates to a method and system for rapid thrust response control of an aero-engine based on redundant actuators, and belongs to the field of aero-engines. The method comprises the following steps: constructing a transfer function for controlling thrust based on the main fuel flow rate and the tail nozzle throat area; calculating the transfer functions of the three modules for controlling thrust based on the main fuel flow rate and the tail nozzle throat area; solving the transfer functions for controlling thrust based on the main fuel flow rate and the tail nozzle throat area, and designing a valve position control (VPC) controller based on the transfer function L, thereby achieving rapid thrust response control. While increasing the thrust control bandwidth, the present invention avoids the problems of turbine inlet temperature exceeding the limit and compressor surge caused by the high bandwidth under traditional single-variable control.

The present invention discloses a numerical simulation method and system for a reverse jet of a reusable carrier rocket. The method comprises: establishing a nozzle-related grid model; using the nozzle throat as the inlet boundary for jet calculation and determining other relevant boundary conditions of the nozzle; controlling the nozzle throat to give a given mass percentage according to the actual fuel gas components in the engine, and controlling the incoming air flow to give a given air component percentage according to the actual incoming flow encountered; and controlling the incoming flow Mach number and the static pressure value of the nozzle throat used for the reverse jet of the carrier rocket to gradually change during the calculation process, so as to perform simulation calculations on the reverse jet of the carrier rocket.

The invention discloses an adjustable dynamic and static ring for a coal mill, and relates to the technical field of coal mills.The upper portion of a millstone is provided with an annular milling channel, one side of the bottom of the millstone is connected with a dynamic ring mechanism through a bolt, the radial outer wall of the dynamic ring mechanism is in lap joint with a bearing mechanism, and the upper portion of the bearing mechanism is provided with a first static ring mechanism; a second static ring mechanism is arranged on the upper portion of the first static ring mechanism, the movable ring mechanism is located below the second static ring mechanism, gaps are reserved among the movable ring mechanism, the bearing mechanism, the first static ring mechanism and the second static ring mechanism, and an L-shaped channel is formed. According to the adjustable dynamic and static ring for the coal mill, an air duct and a nozzle are redesigned, the air duct nozzle is subjected to Venturi design, the air speed is gradually increased from an inlet to an outlet of the nozzle and reaches the maximum at the throat part of the nozzle, the ventilation resistance can be reduced, a sealing structure is redesigned, a dynamic and static gap can be ensured, primary air leakage is reduced, and primary air is efficiently utilized; pulverized coal can be carried more effectively, and the output of the coal mill is ensured.

The utility model relates to the field of natural gas stations, in particular to a device for detecting the back pressure ratio of a critical flow venturi nozzle. The device for detecting the backpressure ratio of the critical flow venturi nozzle comprises the critical flow venturi nozzle, a detection pipeline and a backpressure ratio detection control system, the critical flow venturi nozzle is arranged on the detection pipeline in a communicated mode, detection points are arranged on the detection pipeline corresponding to the two ends of the critical flow venturi nozzle respectively, and the backpressure ratio detection control system is connected with the detection pipeline. And the backpressure ratio detection control system is used for collecting a pressure difference value of the two detection points. The gas flow standard device has the advantages of being simple and reasonable in structural design, capable of effectively monitoring the pressure difference between the front portion and the rear portion of the critical flow venturi nozzle and judging whether the throat of the nozzle reaches the critical flow state or not, and capable of effectively improving the reliability of the gas flow standard device adopting the critical flow venturi nozzle method.

This application provides a centrifugal-assisted laminar atomization device, which relates to the field of additive manufacturing technology. By combining the centrifugal force generated by a centrifugal liquid distributor to assist the metal melt in forming a liquid film and then ejecting it, with the sonic airflow generated at the throat of the Laval nozzle and the supersonic airflow generated in the acceleration section, this overcomes the traditional laminar atomization's reliance on a small nozzle aperture, improves metal powder production efficiency, reduces the requirement for positive pressure driving the smelting chamber, and enhances operational safety.

The invention relates to the technical field of atomization conveying devices, in particular to a pneumatically-controlled atomization leading-in device which comprises a shell, a liquid guiding device, an air pump, a controller and an injection mixing assembly, the shell is provided with a bottle neck connecting cavity, and the bottle neck connecting cavity is used for being detachably connected with a bottle neck of a liquid storage bottle in a sealed mode; the bottle mouth connection cavity is provided with a one-way gulp valve, and the one-way gulp valve is communicated with the outside and the interior of the liquid storage bottle so as to supplement air to the liquid storage bottle; the injection mixing assembly is provided with a gas inlet, a suction inlet and a mixing outlet and comprises a gas nozzle, a throat part and a diffusion section which are communicated in sequence, the gas inlet is communicated with the gas nozzle, the suction inlet is communicated with a low-pressure area of the throat part, and the mixing outlet is communicated with the diffusion section; and the mixed gas-liquid two-phase mixture flows through the mixing outlet, enters the liquid guide inlet and is atomized and output by the atomizing nozzle, so that the effects of more continuous spray output and more uniform atomization are realized.

The application relates to a preparation method of a high-density graphite-based dissipation heat-resistant composite material. In order to solve the problems of high cost of the existing dissipation heat-resistant composite material and poor ablation resistance of the graphite dissipation heat-resistant composite material, the preparation method comprises the following steps: mixing multi-element dissipation agent raw materials, uniformly mixing the multi-element dissipation agent raw materials, loading the multi-element dissipation agent raw materials into a graphite crucible, processing a high-density graphite base into a shape to be prepared, mounting the high-density graphite base on a lifting rod of a vacuum infiltration furnace, preparing a dissipation agent alloy melt, and immersing the graphite base in the dissipation agent alloy melt to obtain the high-density graphite-based dissipation heat-resistant composite material. The high-density graphite-based dissipation heat-resistant composite material is prepared by using the vacuum infiltration method, high-purity graphite is used as the base, the composition of the dissipation agent alloy is adjusted, the dissipation agent is wetted with the graphite base, and the ablation resistance of the workpiece is improved. The application can be used for preparing aircraft engine nozzle throat liners, aircraft nose cones and wing leading edges and the like components.

To suppress deceleration of a jet blown out from a top-blowing lance provided with a flip-flop nozzle and to suppress spitting in refining of molten metal.SOLUTION: A flip-flop nozzle provided in the top-blowing lance for refining according to one aspect of the present disclosure has dimensions satisfying the following relationship. Here, L1 is the total length (m) of the connecting pipe, L2 is the short side length (m) of the nozzle throat part, L3 is the diameter (m) of a circle having the same area as the opening area in the cross section of the connecting pipe, and L4 is the long side length (m) of the nozzle throat part.SELECTED DRAWING: Figure 4

This application belongs to the field of turbofan engine starting design technology, specifically involving a turbofan engine backwind starting method, including: Step 1, identifying whether the turbofan engine is starting under high-speed backwind conditions by whether the low-pressure rotor reverses; if the low-pressure rotor reverses, the turbofan engine is identified as starting under high-speed backwind conditions; Step 2, after identifying that the turbofan engine is starting under high-speed backwind conditions, determining the wind pressure resistance PdX of the turbofan engine starting under high-speed backwind conditions by the low-pressure rotor reverse rotation speed and the correspondence between the low-pressure rotor reverse rotation speed and wind pressure resistance; Step 3, after the low-pressure rotor changes from reverse rotation to forward rotation under the starter motor, reducing the nozzle throat area A8, adjusting the nozzle exit area A9 and vector angle δA9 to shield the nozzle throat, increasing the ignition speed to ignite the turbofan engine, and increasing the fuel supply speed to supply fuel to the turbofan engine, thereby starting the turbofan engine.

The invention relates to the technical field of gas flow measurement, and discloses a deposition early warning method and system for a sonic nozzle gas flow standard device, and the method comprises the steps: collecting a dynamic pressure signal of upstream gas of a sonic nozzle, and recognizing and segmenting a transient risk window; transmitting an ultrasonic detection signal to the airflow in the sonic nozzle, receiving a penetration signal of the airflow, and extracting a coherent acoustic characteristic quantity used for representing the state of a boundary layer of the throat wall surface of the nozzle; and performing comparative analysis on the coherent acoustic characteristic quantity and a pre-established reference characteristic spectrum to generate early warning information. According to the method, a progressive accurate diagnosis chain from macroscopic fluid dynamic capture to microscopic surface effect detection to metering risk quantitative evaluation is constructed, so that the fundamental technical difficulty that silence misalignment caused by deposition of a sonic nozzle gas flow standard device is difficult to perceive and quantitatively evaluate is solved; and the reliability of the detection result of the device is improved.

A fluid inhalation device, comprises a casing having therein a fluid reservoir, a fluid-air outlet connected to a top end of the fluid reservoir, a vacuum channel, having a bottom end connected to a bottom end of the fluid reservoir, an air duct having an air inlet at a first air duct end, and a nozzle connected to a second air duct end through a nozzle throat and connected to the fluid reservoir through a nozzle exit, a top end of the vacuum channel is connected to the nozzle. The fluid inhalation device may also include a filling port, fluidly connected to the fluid reservoir; and / or one or both of an air duct valve, and the fluid-air channel valve.

The present application relates to a kind of hypersonic carbon dioxide profile nozzle design method, belong to wind tunnel test field;Hypersonic carbon dioxide nozzle is set by expansion section, throat and contraction section three parts;Contraction section is determined by straight line plus circular arc curve;Expansion section is determined by circular arc curve and straight line;Smoothly connect the circular arc curve of contraction section and expansion section, i.e. get conical nozzle curve;The junction of contraction section and expansion section is throat;Nozzle throat diameter is by equivalent specific heat ratio and numerical calculation;Expansion section is determined by characteristic method and numerical correction;Contraction section is determined by straight line plus circular arc curve;The present application provides high-quality hypersonic wind tunnel test aerodynamic data for Mars reentry vehicle development, can simulate Mars flight environment.

The application discloses an aero-engine thrust fast response redundant control method and system considering combustion delay, and belongs to the technical field of aero-engine control. The method steps are as follows: an open-loop transfer function L of main fuel flow and tail nozzle throat area respectively controlling thrust is established based on a desired thrust closed-loop bandwidth; a decoupling condition between the variable tail nozzle throat area and the thrust is set to eliminate the mutual influence between them; four undetermined RTM controller functions in the transfer function L are solved; the actuator transfer functions of the main fuel flow and the tail nozzle throat area are set as first-order systems for solving; system identification is carried out at an engine steady-state working point to obtain a transfer function of a difference between the main fuel flow and the tail nozzle throat area relative to a steady-state value to a difference between the thrust and the steady-state value; the transfer function L is solved, and then the RTM control is completed according to the transfer function L, so that the fast response control of the thrust is realized. The application solves the key technical problems in the prior art.

The invention discloses a design method of a wedge-shaped grain for testing a combustion rate by an impulse method based on a pressurization rate boundary. The problem that in an impulse method experiment, when an inner hole surface-increased combustion tubular grain is adopted for measuring the dynamic combustion speed of a solid propellant under different pressure intensities, the pressurization rate of a high-pressure-index propellant in the later stage of combustion is too high, and consequently the combustion speed cannot respond to pressure intensity changes in time is mainly solved. The method has the innovation points that (1) a mathematical relationship between the combustion surface area size and the change rate and the influence of the nozzle throat diameter on the pressurization rate is established, and a design method for controlling the pressurization process by regulating and controlling the combustion surface area is provided; (2) an outer wedge-shaped grain is designed on the basis of a traditional tubular grain, the combustion surface area and the change rate of the combustion surface area in the later stage of combustion are reduced, and the pressurization rate in the later stage of combustion is inhibited; and (3) in the design process of the wedge-shaped grain, the specific design process of the wedge angle of the wedge-shaped grain, the thickness of the cylinder section and the sizes of other grains is given in combination with the pressurization rate, and the design process of the wedge-shaped grain is standardized.

The application belongs to the technical field of engine control, and particularly relates to a deceleration control method and device for improving fan stability margin. The method comprises the following steps: S1, obtaining an engine deceleration start time, a low-pressure conversion speed after deceleration and a nozzle throat area; S2, discretizing a low-pressure conversion speed change interval into a plurality of low-pressure conversion speed control amounts; S3, superimposing a nozzle throat area increase amount on the basis of an initial value of the nozzle throat area to form a first nozzle throat area, and simultaneously determining a second nozzle throat area for maintaining stable operation of the fan; S4, selecting a minimum value from the two nozzle throat areas and a maximum value of the nozzle throat area to form a nozzle throat area adjustment amount corresponding to the low-pressure conversion speed control amount; and S5, adjusting the nozzle throat area according to the corresponding relationship between the low-pressure conversion speed control amount and the nozzle throat area adjustment amount. The application can ensure that the deceleration time meets the index requirement and improve the aircraft maneuvering performance.

The present application relates to atomization delivery device technical field, especially in pneumatic control's atomization guide device, including casing, liquid guide device, air pump, controller and injection mixing assembly, the casing is equipped with bottle mouth connection cavity, the bottle mouth connection cavity is used for with the bottle mouth of liquid storage bottle can be detached seal connection;The bottle mouth connection cavity is equipped with one-way air supplement valve, the one-way air supplement valve is communicated with the outside and the inside of the liquid storage bottle, in order to be supplemented to the liquid storage bottle air;The injection mixing assembly has gas inlet, suction inlet and mixing outlet, and includes the gas nozzle, throat and pressure recovery section that are communicated in turn, wherein, the gas inlet is communicated with the gas nozzle, the suction inlet is communicated with the low pressure area of the throat, and the mixing outlet is communicated with the pressure recovery section;Mixed gas-liquid two-phase mixed flow through the mixing outlet enters the liquid guide inlet and is atomized by the atomizing nozzle and is output, realizes the effect that spraying output is more continuous, atomization is more uniform.

The invention relates to the field of oil and gas production engineering, in particular to a jet pump process parameter design method considering gas and liquid phases and related products. Calculating the suction pressure of the jet pump; the minimum cavitation area of the jet pump is calculated, and multiple nozzle-throat combinations of the jet pump are determined; determining the power hydraulic pressure; calculating the flow of the power liquid, and determining the discharge pressure; calculating a dimensionless mass flow ratio; calculating a dimensionless pressure ratio; iterative calculation is carried out, and an optimal combination is obtained through screening from various nozzle-throat combinations; determining process parameters of the jet pump; determining ground pump parameters based on the process parameters of the jet pump; according to the method, the optimal operation parameters of the jet pump are determined by calculating the flow characteristics of the gas-liquid mixed fluid in the well, the accuracy of pump parameter design when the jet pump lifts the gas phase and the liquid phase can be improved, and the negative influence of the gas phase proportion on the operation performance of the pump is reduced by introducing correction calculation of the dimensionless pressure ratio and the dimensionless mass flow ratio.

The application belongs to the field of aircraft design and is a method for subsonic cruise state fuel consumption of a small-bypass-ratio turbofan engine. The method comprises the following steps: obtaining initial performance record results of the whole machine in a subsonic cruise state, analyzing and judging whether the working state of the small-bypass-ratio turbofan engine is in an optimal state, and optimizing a preliminary design of a cruise fuel consumption debugging scheme to determine a preliminary adjustment scheme of an optimal fan guide vane angle a1 and a preliminary adjustment scheme of an optimal compressor guide vane angle a2; further adjusting a nozzle throat area A8 and a nozzle outlet area A9 to different areas to determine an optimal nozzle throat area A8 and an optimal nozzle outlet area A9; and finally judging installation fuel consumption under the condition of the whole aircraft to obtain an optimal installation fuel consumption state when the installation fuel consumption is optimal. The method systematically and normatively proposes a debugging step for optimizing subsonic cruise state fuel consumption, which can effectively reduce engine installation fuel consumption.

A spin-die manifold includes a nozzle throat having long sides and short sides, in which a spinning pack is arranged with a spinneret arranged underneath, and at least one distribution block having a spinning pump. Liquid plastic is conveyed to the spinning pump via an extruder, which conveys the liquid plastic to the spinning pack via the at least one distribution block via distribution lines arranged inside the distribution block. At least one distribution block is arranged on a long side of the nozzle throat. The nozzle throat has at least one surface heating element on each of its vertical flat long and short sides. The at least one distribution block has at least one surface heating element on at least one part of its upper or lower outer surface. The surface heating elements electrically heat at least this part of the long and short sides and outer surface.

This invention discloses a tie-rod type nozzle structure with adjustable throat area, relating to the field of fluid machinery, aiming to solve the technical problem that existing fixed nozzles cannot achieve stepless adjustment of the throat area. It includes a fixed nozzle, a movable nozzle sleeved on the rear section of the fixed nozzle, an inner cone forming an exhaust channel, and multiple tie-rod assemblies distributed circumferentially. The two ends of each tie-rod assembly are connected to the fixed nozzle and the movable nozzle respectively, and their lengths are adjustable. By synchronously rotating the double-ended studs of each tie-rod assembly, the movable nozzle can be driven to slide axially relative to the fixed nozzle, changing the axial relative position of the movable nozzle outlet and the inner cone, thereby achieving stepless and continuous adjustment of the nozzle throat area. This invention has a simple and reliable structure, is convenient and flexible to operate, and only requires one device to meet a wide range of flow rate adjustment needs, significantly reducing the cost and cycle of multi-scheme matching tests, making it particularly suitable for application scenarios such as matching tests of aero-engine exhaust systems.

This invention discloses a flow control bypass for a nozzle with a pressure-stabilizing chamber, comprising a bypass inlet, a bypass outlet, and a pressure-stabilizing chamber sequentially distributed upstream to downstream along the airflow direction within the nozzle. The internal flow channel of the nozzle includes a nozzle inlet, a straight section of the internal flow channel, a converging section of the internal flow channel, a nozzle throat, an expanding section of the internal flow channel, and a nozzle outlet, sequentially distributed along the airflow direction. The bypass inlet is upstream connected to the straight section of the internal flow channel and downstream connected to the pressure-stabilizing chamber. The bypass outlet is upstream connected to the pressure-stabilizing chamber and downstream connected to the nozzle throat and / or the expanding section of the internal flow channel. The pressure-stabilizing chamber receives the airflow from the bypass inlet, rectifys it within the chamber, and then exits through the bypass outlet. This invention reduces the weight of the flow control bypass wall while simultaneously achieving airflow rectification within the pressure-stabilizing chamber, resulting in better uniformity and less airflow pulsation in the airflow exiting the pressure-stabilizing chamber.

The utility model discloses a pressure-enhanced cooling device of a plateau tunnel construction machinery engine, and relates to an engine cooling system of construction machinery. The cooling device is characterized in that cooling fins are mounted on the outer wall of a cooling liquid tank, an air supply system is mounted on the surfaces of the cooling fins and comprises an air compression channel and an air source inlet, a spray pipe is mounted in the air compression channel, an inlet of the spray pipe is trumpet-shaped, a throat portion of the spray pipe is closely connected to the inlet, and the throat portion is in a contraction state relative to the inlet. The nozzle throat and the nozzle body are in an expanded state. Compared with the prior art, the cooling fin has the advantages that the air compression channels are additionally arranged on the cooling fin, the spray pipes are installed in the air compression channels, the temperature of air passing through the spray pipes is rapidly reduced, then efficient cooling of an engine of the plateau tunnel construction machine is achieved, a reliable cooling solution is provided for plateau tunnel construction, and the working efficiency is improved. And normal operation of the construction machinery in a severe environment is ensured.

The utility model discloses a novel bubble atomizing nozzle which comprises a nozzle body, the nozzle body comprises a liquid phase main flow area, a gas phase injection area and a mixing cavity, a liquid passing opening is formed in the middle of the liquid phase main flow area, a gas passing opening is formed in the gas phase injection area, and a gas injection hole is formed in the mixing cavity. A conical acceleration section is integrally formed at the front end of the mixing cavity, a nozzle throat part is arranged at the end of the conical acceleration section, and liquid enters the liquid phase main flow area through a liquid passing opening. According to the novel bubble atomizing nozzle, a bubble atomizing experimental device is built according to the working characteristics of the bubble atomizing nozzle, the bubble atomizing experimental device mainly comprises a gas path and a liquid path, and the gas path and the liquid path are communicated with each other except that an air compressor provides a gas-phase working medium and provides power for a coating pump and the coating pump provides a liquid-phase working medium. The gas path and the liquid path are mainly composed of a pressure reducing valve, a pressure maintaining valve, a needle valve, a rotor flow meter, a pressure gauge and other instruments, and performance testing can be better carried out.

The utility model discloses a nozzle support frame and 3D printer, including the support plate, said support plate is L-shaped, also be equipped with the cooling block that cooperates with the nozzle throat pipe on the support plate, be equipped with the air-cooling chamber in the cooling block, the air-cooling chamber and the nozzle throat pipe are arranged coaxially, the radius of air-cooling chamber decreases gradually along the nozzle throat pipe extrusion direction, and the air-cooling chamber is equipped with the air-cooling chamber in the nozzle throat pipe extrusion direction. Cooling assemblies matched with the air cooling cavities are further arranged on the two sides of the cooling block. And the conical air cooling cavity is formed in the cooling block, so that cooling air passes through the air cooling cavity at different flow speeds, uniform heat dissipation from slow to fast is carried out on the spray head in the material extruding direction, and the heat dissipation effect of the spray head is improved.

The disclosed assembly includes an exhaust gas turbine housing having inner and outer walls defining first and second exhaust gas channels to a turbine wheel space where an inner wall includes an inner wall end and an outer wall includes an outer wall end, both at the turbine wheel space. A first flow body is disposed adjacent to the inner wall end. A second flow body is disposed adjacent to the outer wall end. At least one set of adjustable variable geometry nozzle vanes define nozzle throats that direct flow of exhaust gas from at least one of the exhaust gas channels to the turbine wheel space At least one of the first flow body and the second flow body includes a concave trailing surface defined in part by an extension of an airfoil surface.

Munition comprising a base and an insert. The present invention relates to ammunition comprising a projectile (1), a propellant charge (3), and a priming device (5) held together by a case, the case forming a nozzle, a nozzle throat, a combustion chamber (4j), and a primer channel. The ammunition is characterized in that the case consists of at least two parts: a base (4b) and an insert (4a), said parts being assembled together after the propellant charge (3) has been inserted into the combustion chamber (4j). Figure for the abstract: Figure 2