34 results about "Deflagration to detonation transition" patented technology

A detonation chamber for a pulse detonation combustor including: a plurality of dimples disposed on at least a portion of an inner surface of the detonation chamber wherein the plurality of dimples enhance a turbulence of a fluid flow through the detonation chamber

The invention relates to a testing device and method for deflagration to detonation transition. The device comprises a sample tube, a verification plate and a plug, wherein the sample tube is used for containing a sample to be tested, the verification plate is fixedly installed at one end of the sample tube and used for packaging the sample and detecting whether a perforation is formed in the verification plate or not during combustion of the sample, and the plug is fixedly installed at the other end of the sample tube. The method comprises the steps that the sample is ignited for testing when the sample is packaged in the sample tube, and meanwhile, detonation velocities of the sample between adjacent test holes are tested to obtain at least two groups of detonation velocities; if the perforation is formed in the verification plate, it proves that the sample has the deflagration to detonation transition, or if the detonation velocity of the sample is stable, it proves that the sample has the deflagration to detonation transition, wherein the stability of the detonation velocity of the sample refers to that the standard deviation of at least two groups of detonation velocity values is not more than 35. The device is particularly applicable to deflagration to detonation transition tests of high-energy propellants. Compared with traditional testing methods and devices for the deflagration to detonation transition, the testing device and method have the advantages that two evaluation indicators, namely, the perforation and the stable detonation velocity are adopted, so that the testing efficiency and the data credibility are improved.

The invention relates to a jet ignition device of a pulse detonation engine, which is characterized in that a jet tube is fixedly connected with a mixing chamber through a sealing clamp nut, an adjusting plug is mounted at the top end of the jet tube through a sealing nut and a clamping nut; a drain tube is arranged in a jet chamber inside the jet tube and is connected with the jet tube through a fixing rib, and the lower end of the drain tube extends into the mixing chamber; and an ignition seat is arranged on one side of the jet tube and is located at one end of an outlet of the drain tube. Compared with the time and the distance for generating detonation waves by normal ignition devices, the time and the distance for generating the detonation waves by the jet ignition device are shorter, accordingly the DDT (deflagration to detonation transition) time and distance is shortened. In this case, length of a detonation chamber can be further shortened so as to improve working frequency of the pulse detonation engine. After the detonation chamber is shortened, exhausting burden in the pulse detonation engine is reduced, so that expansion wave-beams generated from the outlet of the pulse detonation engine can catch up with pressure waves transmitted before, pressure disturbance in an air-inlet passage is reduced, and working stability of the pulse detonation engine is enhanced while better propulsive performance is achieved.

The invention provides a detonation tube structure of a multi-tube pulse detonation engine, which is characterized by comprising at least two detonation tubes, wherein the central axes of all detonation tubes are uniformly distributed along the circumferential direction; two adjacent detonation tubes along the circumferential direction are communicated through a circular arc flame crossover tube; the internal diameter ratio of the flame crossover tube to the detonation tubes is 1/3:1; the distance between the central axis of the flame crossover tube and the fuel nozzle of each detonation tube is 2 to 4 times the internal diameter of the detonation tube; and an igniter is arranged at the middle position of the wall of each flame crossover tube. By the detonation tube structure, the ignition energy of a single tube in the multi-tube pulse detonation engine can be improved on the premise of small energy ignition, the deflagration to detonation transition (DDT) distance of the single tube under the same ignition condition is shortened, the adverse effect of fuel gas back transmission on the air-breathing multi-tube pulse detonation engine can be reduced, and the synchronism of multi-tube work is improved.

An apparatus includes a thermally-activated, deflagration initiation device, a deflagration-to-detonation transition manifold, a first transfer line connecting the deflagration initiation device and the deflagration-to-detonation transition manifold, and a linear shaped charge coupled with the first transfer line. An apparatus includes a heat-to-detonation transition manifold, a heat pipe connected to the transition manifold, a linear shaped charge, and a transfer line connecting the heat-to-detonation transition manifold and the linear shaped charge. An apparatus includes a thermally-activated pyrotechnic train and a linear shaped charge coupled with the pyrotechnic train. A method includes initiating a deflagrating material at a predetermined temperature or within a predetermined range of temperatures, initiating a detonating material with the deflagrating material, and initiating a linear shaped charge with the detonated material.

The invention discloses a deflagration-to-detonation transition energy gathering explosive device, and belongs to the technical field of explosive devices. The deflagration-to-detonation transition energy gathering explosive device comprises a high-pressure electric spark ignition device and an energy gathering explosive device, wherein the energy gathering explosive device comprises an explosivecharging container and a shaped charge cover; the explosive charging container comprises a barrel-shaped explosive charging container body and a top cover; an ignition electrode mounting hole is formed in the top cover; the shaped charge cover is arranged in the barrel-shaped explosive charging container body; a detonating explosive charging layer, a booster explosive layer and a high explosive layer are arranged above the shaped charge cover inside the barrel-shaped explosive charging container body from top to bottom in sequence; the detonating explosive charging layer comprises a mixed explosive charging layer, a bulk hexogen layer and a hexogen grain from top to bottom in sequence; the mixed explosive charging layer is a mixture of black powder, active metal powder and perchlorate; thehigh-pressure electric spark ignition device comprises a power source, a pressure rising device and two ignition electrodes; and the two ignition electrodes are arranged on one insulation plug whichis arranged in the ignition electrode mounting hole. The deflagration-to-detonation transition energy gathering explosive device can realize safe and stable detonation, generates effective shaped charge jet and is suitable for silenced detonation.

The invention discloses a spiral multi-channel pulse detonation engine which comprises an engine shell, spiral partition plates, gas inlet slots, a plurality of spark plugs and a gas inlet rotor. The engine shell is circular, the spiral partition plates are fixed onto an inner ring wall of an annular cavity to form spiral channels, and the gas inlet slots are formed in the inner ring wall and are positioned among the spiral partition plates; two spiral slots which are in identical shapes are formed in the gas inlet rotor and are used as common gas inlet channels. The gas inlet rotor is in close fit with an inner ring of the engine shell and can freely rotate. The multiple spark plugs are mounted at the ends of the engine, are correspondingly matched with the spiral channels on the inner ring wall and are controlled by a computer, an automatic ignition effect can be realized according to the rotational speed of the gas inlet rotor and phase of the gas inlet channels, and accordingly a multi-tube time-sharing initiation effect can be realized. The spiral multi-channel pulse detonation engine has the advantages that a low-energy ignition mode is adopted by the engine, so that axial DDT (deflagration to detonation transition) distances can be shortened, and the spatial size of the engine can be effectively utilized; the gas inlet slots are formed in positions along a detonation chamber, and gas can flow into the spiral multi-channel pulse detonation engine via the gas inlet slots, so that the spiral multi-channel pulse detonation engine is short in filling time and high in gas inlet filling speed, and the detonation frequency can be increased.

A method of rotating a crank shaft and in internal detonation engine are provided. The internal detonation engine comprises a deflagration to detonation transition section. The deflagration to detonation transition section is connected to a main cylinder, which houses a piston. Inducing a detonation wave from the deflagration wave and passing the detonation wave through a fluid, gives rise to high pressure and temperature in a cylinder and pushes a piston towards bottom dead center. An internal detonation reciprocating engine may be a single cylinder and may be either a two or four stroke engine. A two-stroke internal detonation reciprocating engine is similar to a four-stroke internal detonation reciprocating engine but has different valve placements. Detonations produce a more thorough combustion of the fuel and may, thereby, yield reduced emissions of carbon monoxide as compared to internal combustion engines.

The invention provides a pulse detonation engine with an ejector and a method for processing a main detonation tube. The invention is characterized in that one end of an ejector is a horn-shaped expansion section, the wall surface of the expansion section is a 1/4 arch wall surface; the relation between the radius R of an arc section and the inner diameter D of a cylindrical section is as follows: 2/5is less than or equal to R/Dis less than or equal to 3/5; the ejector and a main detonation tube are installed coaxially, the relation between the inner diameter d of the main detonation tubes and D is as follows: 2/5is less than or equal to d/Dis less than or equal to 3/5; L represents the axial distance the main detonation tube stretches into the ejector, the relation between L and d is as follows: 2is less than or equal to L/dis less than or equal to 6; a spiral channel is arranged in the tube wall of the main detonation tube. In the invention, by designing the entrance structure of the ejector, the structural relationship between the main detonation tube and the ejector and the spiral channel in the tube wall of the main detonation tube, reignited fuel oil can be fully heated inside the tube wall, which is conducive to the reduction of DDT (deflagration to detonation transition) distance, the lowering of the temperature of the main detonation tube and the lengthening of the thermal fatigue life of the main detonation tube.

The invention discloses an essentially safe detonator for civil use or engineering blasting. According to the safe detonator, a perchlorate carbon hydrazide complex is served as an initiating explosive; and the pressure switching effect exists in the deflagration to detonation transition process of such initiating explosives, so that the deflagration to detonation transition process can be realized reliably in an airtight state of sealing the detonator, thereby outputting detonation waves; and the deflagration to detonation transition process cannot be realized in a pressure relief state of opening the detonator. Therefore, the detonator only utilizing the initiating explosive has special use safety and reliability and can be assembled together with the electric ignition components of an electric heating wire, magnetoelectric ignition components, the ignition control components of an electronic circuit or the ignition components of an explosive-guiding pipe to form a safe electric detonator, a safe magnetoelectric detonator, an essentially safe electronic detonator or a safe explosive-guiding detonator so as to be used for civil blasting equipment. As a result, accidental explosion accidents are controlled effectively as well as terrorist events are prevented.

The invention provides a backflow type detonation tube structure for a pulse detonation engine. With a bent pipeline structure adopted, the axial distance of the detonation tube can be greatly reduced, the axial length of the pulse detonation engine can be decreased, the weight of the pulse detonation engine can be reduced, the structure of a detonation combustion chamber is more compact, the heatcapacity intensity of the combustion chamber can be increased, and the engine can obtain greater thrust/power; and with a fan-shaped pipeline structure adopted, the detonation tube in the combustionchamber is distributed more reasonably, and the capacity of the detonation tube is larger, and therefore, the thrust of the pulse detonation engine can be improved; a fan-shaped obstacle in the detonation tube has a semi-circular cross section, and the fan-shaped obstacle enables a better DDT (deflagration to detonation transition) shortening effect compared with an ordinary rectangular-section obstacle.