121 results about "Pump-jet" patented technology

The invention provides a fluid-structure interaction vibration simulation and suppression method for a water-jet propeller, and belongs to the field of numerical simulation of computational fluid mechanics. The method comprises the following steps: establishing a finite element model of a water-jet propeller impeller-shafting coupling system; performing dry mode and wet mode comparative analysis on the finite element model by utilizing a finite element method, and verifying the effectiveness of the model; dividing finite element grids of a structural domain and a flow field domain; establishing a fluid-solid coupling model; on the basis of bidirectional fluid-solid coupling numerical calculation, the flow field speed and acting force are solved through CFD, the structure movement speed and displacement are updated, a flow field grid is further updated, flow numerical calculation continues to be conducted, and iteration is conducted till the simulation time ends; flow-induced vibration characteristics are analyzed through post-processing, and the vibration amplitude is restrained by adjusting the mass center position of the impeller airfoil. According to the method, the bidirectional fluid-solid coupling model of the impeller-shafting system of the water-jet propeller is constructed, structural deformation and transient flow field information are directly associated, and the hydrodynamic performance is improved.

The invention provides an automatic berthing method and device for a single boat in the new quality field, and relates to the technical field of automatic control of boats in the new quality field. Static berth information and a sensor sensing result are fused to construct a task situation package containing a multi-moving-obstacle trajectory prediction set and a dynamic prohibited area set, dynamic collision avoidance guidance is executed in a first-stage tracking path, and a staged deceleration strategy of vector motion and hovering is switched to obtain a berthing point state set when conflicts occur. Performing in-situ heading adjustment by using the state set of the berthing point, outputting consistent heading, zero navigational speed and position states, executing target point type vector approach guidance in the second stage, hovering when a collision risk is predicted, and recovering vector motion control in a safe time window to complete lateral positioning welt berthing. And finally, precise thruster control instruction output is achieved through thrust distribution of the double water-jet thrusters. According to the invention, automatic berthing of the new-quality field single boat under the condition of multiple moving obstacles can be realized.

The invention relates to an array type underwater propeller with high maneuverability and low energy consumption, a pump jet generating device and a flow divider jointly form a propeller front end, an intelligent fluid director forms a propeller rear end, and the pump jet generating device drives an impeller through a rotating motor to drive surrounding water flow to rotate to generate a main jet flow; an isolation structure is arranged in the flow divider and used for evenly dividing the main jet flow into multiple strands of independent sub jet flows, and all the sub jet flows form propelling power after entering the intelligent flow guider to be guided. The intelligent fluid directors are connected with the flow channels of the flow divider in a one-to-one correspondence mode and used for converting fluid flowing out of the flow divider and out of the jet flow face into effective action jet flow with the adjustable flow speed. The intelligent fluid director comprises a jet flow end regulation and control mechanism and a pressure relief end regulation and control mechanism, and the jet flow end regulation and control mechanism is used for independently regulating the flow speed of effective jet flow ejected from the fluid director; and the pressure relief end regulation and control mechanism is used for maintaining the constant flow velocity at the inlet of the fluid director by releasing part of water flow when the effective jet flow velocity is regulated.

The invention discloses a hybrid power amphibious vehicle, comprising a retractable double wishbone independent suspension system, a diesel engine, an elastic coupling, a permanent magnet synchronous generator and a reducer arranged on a front frame, a water jet propulsion device, a power battery and an electric wheel. The electric wheel is arranged on the retractable double wishbone independent suspension system and can be extended from or retracted into the vehicle body under the drive of the retractable double wishbone independent suspension system. The elastic coupling is connected to the rotating shafts of the diesel engine and the permanent magnet synchronous generator. The reducer is transmission-connected to the permanent magnet synchronous generator. Two ends of the water jet propulsion device transmission shaft are transmission-connected to the reducer and the water jet propulsion device respectively. A clutch is arranged inside the permanent magnet synchronous generator to control the on-off of the transmission between the permanent magnet synchronous generator and the reducer. The generator is used for driving the electric wheel and charging the power battery, thereby solving the problems of insufficient driving stability of the amphibious vehicle in water and difficulty of the power system in flexibly adapting to driving scenes.

The invention discloses an unmanned ship self-adaptive safety redundancy system for an inland river ultra-shallow water environment and a control method. The system is composed of four-stage closed-loop redundancy of sensing, decision making, execution and laws and regulations. A 0.1 m-stage shallow water three-dimensional map is constructed in real time by a dual-millimeter-wave radar and a high-frequency single-beam sounding sonar; the main and standby controllers process the quay wall effect, backflow and grounding nonlinear disturbance on line through a BLF-RBFNN fixed time convergence algorithm, and the upper bound of convergence time is 4.2 s and is irrelevant to the initial state; the variable-configuration double-pump jet-air cushion hybrid propulsion device adjusts the draft on line according to the water depth of 0.12-0.45 m, and is matched with the self-righting honeycomb composite ship body to automatically stop leakage and return within 60 seconds when the ship body is damaged; and when the ship-end double control fails, the ship-shore cloud collaborative digital twinborn body completes regulation-level minimum risk takeover within 10 seconds. Experiments prove that the path error is less than or equal to 0.08 m and the fault degradation success rate is 100% in a 0.15 m water tank and 0.35 m Yangtze River channel, and zero-grounding, zero-overturning and zero-regulation illegal sailing of the ultra-shallow water unmanned ship is realized.

The invention discloses a ship propulsion system and method, and relates to the technical field of ships, the system comprises a direct current power distribution subsystem, a PTI / PTO motor, a diesel engine, a gearbox, a water-jet propeller and a control subsystem; the direct-current power distribution subsystem is used for supplying power to the PTI / PTO motor; the gear box is used for driving the water-jet propeller under the driving of the PTI / PTO motor and / or the diesel engine so as to propel the ship; and the control subsystem is used for controlling the power flow direction of the PTI / PTO motor and controlling start and stop of the diesel engine, so that the ship operates according to a preset driving mode, and the driving mode comprises a PTI / PTO motor driving mode. By means of the system, when the ship enters a specific area for port operation or sails offshore, the ship is switched to sail in the PTI / PTO motor driving mode, so that the waste gas influence caused by diesel engine driving is avoided, and zero emission is achieved.

The invention discloses a noise reduction and efficiency improvement pump jet propeller C-shaped circumferential bending stator and a design method, and the method comprises the steps: building a hull-rudder-pump jet propeller calculation model, changing the phase angles theta of the stator at different radiuses, and preliminarily determining the lateral slope distance distribution parameter ai of the C-shaped circumferential bending stator; after a pump-jet propeller provided with a straight stator and a C-shaped circumferential bending stator is arranged in an underwater vehicle, self-propulsion test simulation is carried out, and the thrust and torque of each component of the propellers when the two different propellers are at self-propulsion points are monitored; adjusting a slant distance distribution parameter ai of a bent stator side to obtain different distribution forms of circumferential phase angles of the stator; adjusting geometric attack angles alpha of sections at different radiuses of the stator blade, and selecting the most suitable distribution form of the geometric attack angles alpha as an optimization result; and determining the most suitable chordwise distribution form of the blade section as an optimization result. According to the invention, the bearing force, hydrodynamic noise and structural vibration noise of the submarine propeller are reduced only through the lateral inclination change of the stator blades.

A hub surface of a guide vane body of the water-jet propulsion pump is a hemispheroid, guide vane body blades are distributed on the guide vane body, the sides, close to the plane of the hemispheroid, of the guide vane body blades are roots of the guide vane body blades, and the bone surfaces of the guide vane body blades of the water-jet propulsion pump are taken as reference surfaces S; the front side of the guide vane body blade is a pressure face C, the back face of the guide vane body blade is a suction face A, the back face of the micro-baffle structure is a suction face B, one side of the micro-baffle structure is connected with the pressure face of the guide vane body blade, and the other side of the micro-baffle structure extends to the outer edge of the guide vane body blade after being bent. Development of the wake at the root of the impeller in a guide vane body channel is limited, the guide vane body transverse vortex intensity caused by the transverse pressure gradient is restrained, the structure is simple, the efficiency of the water-jet propeller can be improved, and the dynamic flow excitation force of the water-jet propeller can be reduced.

The invention relates to a pump jet propeller which comprises an annular guide pipe, a first stator, a rotor and a propeller hub, the first stator, the rotor and the propeller hub are all arranged in the annular guide pipe, the first stator is close to the tail edge of the annular guide pipe, the first stator and the rotor are connected with the propeller hub, and the first stator is connected with the inner wall of the annular guide pipe. The tail edge of the annular guide pipe is provided with a plurality of sawtooth assemblies which are arranged at intervals in the circumferential direction of the annular guide pipe, the sawtooth assemblies are located between every two adjacent stator blades, each sawtooth assembly comprises at least one sawtooth structure, and the first stator comprises a plurality of stator blades; the rotor is used for rotating and generating water power, so that the pump-jet propeller generates forward thrust; the sawtooth assembly is used for disturbing the wake flow field of the pump-jet propeller to conduct vibration and noise reduction, and the problems that due to a continuously-distributed sawtooth structure, the thrust loss is large, and the noise reduction effect is poor can be solved.

The invention discloses a transmission assembly, and relates to the technical field of automobile transmission. The transmission assembly comprises a front axle frame, a main speed reducer, a front axle transmission shaft, an engine, a gearbox, a transfer case, a rear axle transmission shaft, a spray pump transmission shaft, a rear axle frame and a water-jet propeller, the gearbox is connected between the engine and the transfer case, and the main speed reducer is connected between the front axle frame and the front axle transmission shaft. According to the transmission assembly, the amphibious gear shifting operation function can be achieved through the arrangement of the transfer case and the specific design of the transfer case, power sent by the engine is also sequentially transmitted into the gearbox and then transmitted into the transfer case, gears are controlled by shifting the transfer rod, the engine can transmit the power to the spray pump transmission shaft, and the transmission efficiency is improved. When the vehicle runs, the spraying pump transmission shaft transmits power to the water spraying propeller, so that the water power transmission process is completed, the power of the engine can be switched between a water mode and a land mode, and the adaptive capacity of the vehicle in different environments is improved.

The invention provides a gas-liquid two-phase pump jet propulsion device for an underwater navigation body, and belongs to the technical field of underwater propellers, the gas-liquid two-phase pump jet propulsion device for the underwater navigation body comprises a pump jet assembly, the pump jet assembly is installed in a propeller guide pipe, and the propeller guide pipe is fixedly installed at the rear end of a navigation body shell; the pump jet assembly comprises a paddle shaft, a front stator, a rotor and a rear stator which are sequentially installed in the fluid direction. The gas supply unit comprises a high-pressure gas storage container, the high-pressure gas storage container is communicated with a gas adjusting device through a gas filtering unit, the gas adjusting device is communicated with a gas conveying pipe, the gas conveying pipe is communicated with an annular nozzle, the annular nozzle is connected with an inner cavity of an annular mixing cavity, and the annular mixing cavity is installed in the inner cavity of the annular mixing cavity. The annular mixing cavity is located at the rear end of the pump jet assembly. By fusing the pump spraying momentum transfer principle and the gas-liquid two-phase flow control technology, the thrust can be remarkably improved, and the technical breakthrough of reducing the working noise and improving the cavitation critical speed is synchronously realized.

The invention discloses a hybrid unmanned ship which comprises a ship body, a water-jet propeller is arranged at the tail end of the ship body, shaftless propellers are arranged on the two sides of the ship body, and a fuel power mechanism used for driving the water-jet propeller to move and a hydrogen power mechanism used for driving the shaftless propellers to move are further arranged in the ship body. The hydrogen power mechanism comprises a plurality of hydrogen storage tanks located in the ship body and a hydrogen generator used for receiving hydrogen in the hydrogen storage tanks, the hydrogen power mechanism further comprises a battery, the hydrogen generator is connected with the battery through an electric connecting line, and the fuel oil power mechanism comprises a fuel oil bin and an engine which are located in the ship body. The fuel oil bin is connected with the engine through an oil supply pipeline, the output end of the engine is connected with the power end of the water-jet propeller through the speed-changing gear box, power selection can be carried out according to requirements during sailing, and therefore the sailing speed requirements under various sailing states can be met, and the sailing speed of the water-jet propeller can be adjusted. Meanwhile, the environmental pollution can be reduced.

The invention discloses an autonomous berthing method for a double-water-jet-propeller water surface unmanned ship, and the method comprises the steps: defining a state space, an action space, a reward function and a neural network structure element, employing a reinforcement learning method, and according to the current radar observation information of the unmanned ship, the target berth position information, and the current speed information of the unmanned ship; according to the method, the unmanned ship control output information is obtained, the problems that a traditional manual design berthing collision avoidance rule, a physical motion model, a machine learning method, an environment model and the like are greatly influenced by the environment, and intermediate steps are multiple and complex are solved, the calculation efficiency and the one-time planning berthing success rate are effectively improved, and therefore the berthing efficiency is overall improved.

The invention discloses an autonomous operation, maintenance and cleaning bionic device for a swimming pool and a cleaning method. The autonomous operation, maintenance and cleaning bionic device for the swimming pool comprises a floating body, a filtering assembly and a water spraying propeller. The floating body is provided with a fluid channel for fluid to flow through; the filtering assembly is arranged in the fluid channel; the water-jet propeller comprises a mounting part, blades and a driving part, the mounting part is connected with the floating body, a mounting channel communicated with the fluid channel is formed in the mounting part, the blades are rotationally arranged in the mounting channel, and the driving part is in driving connection with the blades. According to the scheme, while water in the swimming pool is cleaned, foreign matters such as hair are prevented from being wound on blades of the water-jet propeller, the propelling efficiency is improved, the safety is high, the water-jet propeller can be used under the condition that swimmers exist, stable operation of the cleaning device is guaranteed, automation of swimming pool cleaning and maintenance is conveniently achieved, and the service diversity of the swimming pool is increased; and the device can be matched with a series of intelligent devices to ensure efficient and continuous cleaning of the swimming pool, and has wide market application prospects.

The invention discloses a water jet propulsion boat low-speed working condition energy-saving device based on the coanda effect. The water jet propulsion boat low-speed working condition energy-saving device comprises a flow guide plate, a fixed connecting piece and an angle adjusting device. The guide plate is arranged behind a nozzle of the water-jet propeller and is an S-shaped curved surface, the front end is hinged with the fixed connecting piece, and the rear end is hinged with the angle adjusting device; under a low-speed working condition, the guide plate rotates to a folded state, the upper wall surface covers a nozzle of the water-jet propeller and can guide jet flow to flow in a manner of being attached to the guide plate by means of the coanda effect, and the lower wall surface guides circulating vortex in a boat rear wake flow field; under the medium-high speed working condition, the guide plate rotates to a put-down state, the upper wall face is far away from jet flow of the water-jet propeller, and the lower wall face does not generate additional flow field disturbance in the boat body wake flow field. The jet flow of the water-jet propeller and the circulating vortex of the wake flow field of the boat body are guided based on the coanda effect, adverse flow coupling between the jet flow of the water-jet propeller and the circulating vortex is restrained, recycling of effective momentum in the corresponding wake flow field vortex is synchronously improved, and therefore the propelling efficiency of the water-jet propelling boat under the low-speed working condition is improved.

The invention provides a semi-suspended stator pump-jet propeller. The semi-suspended stator pump-jet propeller comprises a guide pipe, a hub, paddles, full-stator blades and semi-suspended stator blades. The hub, the paddles, the full-stator blades and the semi-suspended stator blades are positioned in the guide pipe; the hub and the guide pipe are coaxially arranged, the blades and the full-stator blades are arranged on the outer wall of the hub, the full-stator blades are arranged in the front, and the blades are arranged in the rear; one end of each full-stator blade is fixedly connected with the outer wall of the hub, and the other end of each full-stator blade is fixedly connected with the inner wall of the guide pipe; the semi-suspended stator blades are arranged between the full stator blades, the semi-suspended stator blades are arranged on the inner wall of the guide pipe and extend in the radial direction from the inner wall of the guide pipe to the hub, and the semi-suspended stator blades are arranged between the full stator blades, so that the vortex strength in the area from the rear of the front full stator blades to the front of the blades is changed, and energy dissipation is increased; the vortex intensity of the position behind the semi-suspended stator blade is reduced, the flow field distribution is more uniform, and the efficiency is improved and the flow noise is reduced.

The utility model relates to the technical field of underwater unmanned vehicles, in particular to a novel low-noise energy-saving underwater vehicle propeller, which comprises a propeller body, a plurality of groups of helical blades, a plurality of pressure relief holes and a fixing device, the helical blades are uniformly arranged in an inner cavity of the propeller body, the pressure relief holes are arranged on the helical blades, and the fixing device is arranged in the inner cavity of the propeller body. The screw blade adopts a shaftless pump jet propulsion system, the shaftless pump jet propulsion system eliminates a shaft system and a transmission device in a traditional propulsion system, energy loss is reduced, meanwhile, the stability and reliability of the system are improved, and the design of the pressure relief holes can effectively reduce tip vortex cavitation of a propeller, so that underwater radiation noise is reduced, and the service life of the system is prolonged. And the sliding block is driven to move in the sliding groove under the acting force of the spring, so that the positioning block enters the positioning groove to lock the screw rod, the connecting stability of the screw rod is guaranteed, and the situation that the screw rod is loosened due to long-term impact is avoided.

The invention discloses a pump jet flow field testing device and a flow field missing compensation method. The pump jet flow field testing device comprises a high-frequency double-pulse laser, an image processing system, a camera synchronizer, a high-speed camera, a cavitation bubble water cylinder, a reflecting prism, a pump jet model and a transparent conduit. The high-frequency double-pulse laser is placed at the rear end of the pump spraying model in the cavitation bubble water cylinder, and laser emitted by the high-frequency double-pulse laser irradiates the pump spraying model through the cavitation bubble water cylinder; installing a reflecting prism and a high-speed camera on a laser plane of the pump spraying model; the data assimilation used by the image processing system and based on the generative adversarial network model effectively solve the problems of complex structure shielding, particle concentration loss and flow field information loss caused by wall reflection. According to the invention, the problem that related experimental devices for testing the internal flow field of the pump-jet propeller are not perfect enough is solved, the pump-jet missing flow field is effectively compensated, and the method is of great significance for the pump-jet propeller to know the form evolution law of the internal flow field from the experimental mechanism and to forecast the noise of the subsequent pump-jet propeller and calculate and verify the flow field.

One side of an impeller shell of the water-jet propeller is communicated with an inlet flow channel, a guide vane body is arranged on the other side of the impeller shell, a nozzle is formed in the outer side of the guide vane body, and a plurality of micro-channel structures are arranged at the position, close to the impeller shell, of the bottom of the inlet flow channel. And the inlet flow channel is communicated with the ship bottom through the micro-channel structure. The invention provides a microchannel structure for inhibiting cavitation bubbles in the lower half area of the propeller, water flow at the bottom of a ship is guided to the inner side of an inlet flow channel, jet flow is formed, the low-pressure area in the inlet flow channel and an impeller is impacted, the cavitation intensity in the propeller is inhibited, the structure is simple, and the thrust and reliability of the propeller in a low-navigational-speed state can be improved.

The refrigeration device comprises a heat exchanger and a water-jet propeller, the heat exchanger is provided with a water flow channel, and the water flow channel of the heat exchanger is communicated with a water flow pipeline of the water-jet propeller, so that water flow sucked by the water-jet propeller exchanges heat with the heat exchanger and then is sprayed out from a water outlet. The heat exchanger of the refrigerating device communicates with the water flow pipeline of the water-jet propeller, water flow formed in the sailing process of the water-jet propeller is used for cooling the condenser, integrated design of a propelling system and a refrigerating and cooling system is achieved, and the problems that a traditional independent condenser is large in size and heavy in weight are solved; and the structural complexity and the occupied space of the refrigerating system are obviously reduced.

The utility model relates to an electric surfboard, in particular to an electric surfboard propeller. A coupler on an existing integrated water-jet propeller is externally arranged without protection, multiple waterproof structures along a transmission shaft are complex, and transmission loss is large. The electric surfboard propeller comprises a shell with a flow channel, a coupler and a motor, the bottom and the tail end of the shell are provided with a water inlet and a jet orifice which are communicated with the flow channel respectively, guide vanes and a transmission shaft with an impeller are arranged in the flow channel, and the transmission shaft is connected with the motor through the coupler. The two ends of the transmission shaft are rotationally connected with the shell through a front bearing and a rear bearing respectively, a containing cavity is formed in the front of the shell and provided with a coupler, and the transmission shaft is provided with a first waterproof seal and a second waterproof seal to prevent water from flowing into the front bearing and the rear bearing in the front-back direction along the transmission shaft. The front waterproof seal and the rear waterproof seal are only arranged on the transmission shaft, the waterproof structure is simplified, transmission loss is reduced, the efficiency of the propeller is improved, and meanwhile the coupler is provided with a special arrangement protection cavity.

The present application relates to the technical field of water jet propeller, and discloses a fish environmental protection type water jet propeller based on bionics, which comprises a water inlet pipeline, a water jet assembly is arranged on the water inlet pipeline, and the water jet assembly comprises a main shaft. In order to meet the dual requirements of ship propulsion and water ecological protection, the fish environmental protection type water jet propeller based on bionics is provided with the water jet assembly, the assembly drives the mounting shaft to rotate together with the main shaft, the spherical block and the conical block cooperatively drive the impeller and the propeller to run at high speed, and stable propelling water flow is formed; the straight groove, the connecting groove, the hollow drainage groove and the conical drainage groove of the drainage module constitute a closed loop flow channel, the high-energy water flow downstream of the nozzle is guided back to the inlet edge of the impeller and the propeller through the straight metal pipe and the drainage curved metal pipe, uniform backflow jet flow is formed on the surface of the blade, the bionic vortex screen is generated by the interference of the main flow, the rigid edge of the blade is covered, and small fish are guided to actively avoid.

The invention provides a water-jet propeller impeller structure with self-adaptive guide vanes, and relates to the technical field of water-jet propellers. The water-jet propeller impeller structure with the self-adaptive guide vanes comprises a main body mounting plate body, the upper surface of the main body mounting plate body is fixedly connected with a propeller main pipeline, and the bottom end of the propeller main pipeline is communicated with the surface of the main body mounting plate body; and the surface of the propeller main pipeline is rotatably connected with a horizontally arranged rotary mounting shaft in a penetrating manner. A driving air cylinder is started, the piston end of the driving air cylinder drives a driving connecting rod to move, the driving connecting rod drives a mounting fixing plate to move, the mounting fixing plate drives an annular driving block to move, a driving clamping block drives a second bevel gear to rotate through a second rotating shaft rod, and the second bevel gear drives four first bevel gears to rotate; the first bevel gear drives the guide vane to rotate through the first rotating shaft rod, the opening and closing angle of the guide vane is changed, different requirements are met, and operability is high.

The invention discloses a water-air dual-purpose pump spraying propeller, and relates to the technical field of propelling, the water-air dual-purpose pump spraying propeller comprises a shell, a core shaft and a driving device, the shell is cylindrical, the shell is arranged around the core shaft, and a flow channel for medium conveying is formed between the outer surface of the core shaft and the inner side face of the shell; a medium supercharging device is arranged along the flow channel, and the driving device is used for driving the mandrel to rotate. A combustion chamber in an original aero-engine is abandoned, single-runner axial flow supercharging propulsion is adopted, the problem that the combustion chamber part inevitably becomes dead weight during underwater propulsion is solved, and efficient propulsion work of different media in the air part and the underwater part is achieved by adjusting the rotating speed and the like.

The invention provides a pod type gas-liquid two-phase pump jet propeller, which belongs to the technical field of ships and underwater propulsion, and comprises a pod type shell, paddles, a stator and a bubble generating chamber, the paddle, the stator and the bubble generating chamber are located on the same central axis, the stator is fixedly installed in the front end of the pod type shell and connected with the motor, the motor is connected with the rotating shaft, the rotating shaft is connected with the propeller hub, the paddle is installed on the rotating shaft, the bubble generating chamber is horizontally installed in the middle section of the propeller, and the bubble generating chamber is communicated with the gas channel. The gas channel is installed in the connector, the connector is connected with the pod type shell, and the nozzle is installed at the tail end of the pod type shell. The invention has the stamping effect advantage under the high-speed working condition and the pump jet propulsion characteristic under the low-speed working condition, has the characteristics of high propulsion efficiency, strong cavitation inhibition, wide working condition application range and the like, and is particularly suitable for carrying platforms such as bathyscapes, special ships and the like which need to consider both concealment and power performance.

The application relates to a water jet propeller mounting method, which comprises the following steps: pulling a line, detecting the machining allowance of a flange, detecting the mounting gap between the water jet propeller body and the inner wall of a base, making a boring reference point, mounting a boring row, checking the boring allowance, machining the flange, marking and drilling the base of the water jet propeller, mounting the water jet propeller and mounting a motor, and the like. The mounting precision is high, the mounting is simple, the center line of the water jet propeller is pulled, the step of finding the center of the water jet propeller cylinder is omitted, time and labor are saved.

A propulsion module, a propulsion system, a watercraft, an assembly method for a propulsion module, an assembly method for a propulsion system and an assembly method for a watercraft are provided. The propulsion module includes a waterjet. The propulsion module also includes an electric motor configured to channel seawater through the waterjet, wherein in use, the electric motor is configured to be externally passively cooled by surrounding seawater. Further, the propulsion module includes an electronic speed controller (ESC) connected to the electric motor and configured to control the electric motor, wherein in use, the ESC is configured to be externally passively cooled by the surrounding seawater.

The invention belongs to the technical field of fluid mechanics analysis, and particularly relates to a high-precision calculation method for cavitation of a tip vortex of a rotor of a pump-jet propeller. Comprising the following steps: establishing a pump-jet propeller model; determining a computational domain; performing grid division on the model; establishing cross section monitoring pressure distribution characteristics; cFD calculation is carried out; determining minimum pressure monitoring results of vortex cores of all cross sections under different grid densities, and obtaining a vortex core pressure mean value comparison curve after the maximum size of a grid unit is adjusted; comparing the mean value comparison curves under the vortex core pressure, and selecting a preferable blade tip domain grid size; and a solver is used for solving, and a cavitation model is introduced to obtain a tip vortex cavitation result. According to the method, on the basis of a common multi-channel periodic structure grid, local grid reconstruction is carried out on a rotation domain of a pump-jet propeller rotor in combination with tip vortex flowing characteristics, and finally accurate prediction of tip vortex cavitation of the pump-jet propeller is achieved.

The utility model discloses an independently detachable thrust bearing structure of a water-jet propeller, which comprises a shaft sleeve sleeved on the outer side of an impeller shaft, a locking nut, a thrust bearing, an oil distributing ring and a radial support bearing are sequentially sleeved outside the shaft sleeve along the direction from the end part of the impeller shaft to the root part of the impeller shaft, and a bearing box is arranged outside the thrust bearing and the radial support bearing. The bearing box is connected with the guide vane body; and a bearing cover is arranged between the bearing box and the impeller shaft. The water-jet propeller can be independently replaced without being detached from a ship, and the maintenance cost is low. And meanwhile, the oil path in the bearing cavity is prolonged through the oil distribution ring, the distance between the oil inlet hole and the oil outlet hole is increased, oil is fully circulated in the bearing cavity, and the cooling effect is good.