12 results about "Supercavitation" patented technology

The invention discloses a supercavitation vehicle effluent trajectory prediction method based on BO-FNN. The method comprises the following steps: step 1, constructing a CFD basic mathematical model; 2, based on the mathematical model, boundary condition setting and mesh generation are carried out on the external flow field of the aircraft, and a simulation model is obtained; 3, verifying the simulation model to obtain a numerical model of the water outlet process; 4, an orthogonal test is designed, and a water outlet trajectory data set is obtained according to the numerical model; step 5, designing a feedforward neural network, and fitting the water-out trajectory data set to obtain a water-out trajectory prediction model presenting an over-fitting characteristic; and step 6, optimizing the water outlet trajectory prediction model to obtain a supercavitation vehicle water outlet trajectory prediction model based on the BO-FNN. According to the supercavitation aircraft water outlet trajectory prediction method based on the BO-FNN, the problems that the supercavitation aircraft water outlet process is high in nonlinearity, and prediction cannot be carried out under the multivariable coupling condition are solved.

The application provides a supercavitation projectile cross-medium water entry interference suppression method based on optimization of a cymbal length, comprising the following steps: S1, establishing a projectile-cymbal parameterized model, and demarcating an optimization interval of the cymbal length; S2, coupling a multiphase flow model, a cavitation model and a dynamic grid method to simulate a separation process of the projectile and the cymbal, and obtaining original data of the projectile; S3, performing comparative simulation of multiple groups of different cymbal lengths, and quantitatively extracting three key performance indexes of a supercavity symmetry, a pitch angle deviation and a speed attenuation rate by using the original data of the projectile; and S4, establishing a multi-target optimization criterion based on an interference index, determining a globally optimal cymbal length parameter, and completing the whole optimization process. The application can solve the problem caused by improper design of the cymbal length when the supercavitation projectile and the cymbal cooperatively enter water.

The application belongs to the field of underwater vessels, and particularly relates to an underwater unmanned vehicle. In order to enable the underwater unmanned vehicle to navigate at a high speed and have good self-stability, the application discloses an underwater unmanned vehicle. The underwater unmanned vehicle comprises a front cabin section, a turning section and a rear cabin section, the turning section comprises a front connecting piece and a rear connecting piece, the front connecting piece and the rear connecting piece are respectively provided with front perforations and rear perforations, the front cabin section is provided with at least two jet spouts, the rear cabin section is provided with a cavitation generator, the cavitation generator is connected with a gas guide pipeline, and the front end of the gas guide pipeline is connected with the jet spouts, so that when the cavitation generator is started, high-pressure gas in the cavitation generator is sprayed out from all the jet spouts to form a supercavitation, thereby improving the maximum navigation speed of the underwater unmanned vehicle. By placing the cavitation generator at the rear, the distance between the center of mass and the center of buoyancy can be increased, thereby improving the self-stability of the underwater unmanned vehicle when navigating underwater.

This invention discloses a method for designing ventilation parameters for a supercavitating vehicle. Referring to the vehicle's shape and speed, the required ventilation volumetric flow rate for generating a suitable cavitation bubble size is calculated using the ventilation rate formula. The gas density inside the bubble is determined based on the environmental pressure and required cavitation number. The combustion surface of the solid propellant grain in the gas generator is designed in conjunction with fuel characteristics. Supercavitating vehicles designed using this invention are launched from underwater UUVs and surface ships, primarily for countering underwater targets. The method of this invention can efficiently obtain the ventilation parameters required for generating the appropriate supercavitation size when the vehicle is operating under variable conditions. Furthermore, through reasonable propellant design, the supercavitation size of the vehicle can be easily changed to adapt to changes in operating conditions. This avoids the problem of the vehicle not being fully covered by a supercavitation size that is too small after changing operating conditions, as well as the waste and even performance degradation caused by a supercavitation size that is too large.

The invention discloses a supercavitation vehicle maneuvering navigation dynamic allocation control method considering optimal efficiency, and belongs to the technical field of underwater vehicle control. The method comprises the following steps: establishing an attitude control prediction model of a supercavitation navigation body, and constructing an efficiency evaluation function fusing control precision and control energy consumption; constructing a nonlinear model prediction controller based on the model and the function, and setting a constrained optimization problem and a solving algorithm thereof to complete controller construction; and in each control period, solving an optimization problem through the controller, adjusting a predictive control sequence by using a nonlinear optimization algorithm, and determining optimal allocation by taking the minimization of an efficiency evaluation function as a target to obtain an optimal control sequence. According to the method, the adaptive dynamic distribution of the control instruction among the plurality of execution mechanisms is realized through the NMPC framework, and the problems of low control efficiency and high energy consumption of the supercavitation navigation body in the maneuvering navigation process are effectively solved.

The invention discloses a cross-medium aircraft high-speed water outlet flexible load reduction rectifying device, and relates to the technical field of cross-medium aircraft structure protection. The device conformally wraps the head of the aircraft and sequentially comprises an inner side bonding layer, an anti-static pressure air bag layer, an energy absorption foam layer and an outer side protection layer from inside to outside, underwater collapse is prevented through the internal pressure of preset gas of the anti-static pressure air bag layer, and low-frequency large-displacement buffering is provided through the compressibility of the gas at the water outlet moment; high-frequency impact is absorbed through deformation of the energy-absorbing foam layer, and transition from a blunt-end inner shape to a pointed-end outer shape is achieved. And supercavitation is formed through the streamline shape, so that the water outlet resistance is reduced. Through the material, shape and thickness design of each layer, water outlet resistance reduction and pressure resistance keeping in a deep water environment and efficient buffering at the water outlet moment are achieved, the underwater launching success rate is effectively increased, and precise instruments at the head of an aircraft are protected.

This invention discloses a high-temperature variable-component gas supply system for ventilated supercavitation water tunnel experiments, including a gas source module, which is sequentially connected to a heating module and a gas distribution module via pipelines. It also includes a data acquisition module, with the gas source module and heating module connected to the data acquisition module via signal lines. This invention also discloses an operation method for the high-temperature variable-component gas supply system. This invention solves the problem in existing water tunnel ventilated supercavitation experiments that it is impossible to simultaneously generate, regulate, and supply high-temperature variable-component gas containing condensable phases.

A supercavitation-enhancing paint formulation is disclosed for reducing hydrodynamic drag in underwater applications. The coating comprises a hydrophobic base, nano-additives for cavitation promotion, friction-reducing polymers, and gas-releasing agents. The formulation facilitates vapor layer formation around high-speed objects, improving propulsion efficiency. The paint is applied via a multi-layer process and heat-cured to enhance durability. This innovation enables sustained supercavitation without mechanical modifications, improving performance for underwater vehicles and projectiles.

The invention discloses a response prediction method for a ventilation supercavity flow pattern in a navigation depth change process. The method comprises the following steps: step 1, constructing a mathematical model; 2, on the basis of the mathematical model, boundary condition setting and mesh generation are carried out on the watershed of the aircraft, and a numerical calculation model is obtained; 3, verifying the numerical calculation model to obtain a ventilation supercavitation numerical calculation model suitable for the variable navigation depth condition; and 4, based on the supercavitation numerical calculation model, performing simulation calculation on the ventilation supercavitation flow field under the variable navigation depth condition to obtain a simulation result. According to the response prediction method for the ventilation supercavity flow pattern in the navigation depth change process, the problem that the flow pattern change and response of the cavity in the navigation depth dynamic change process of the supercavity vehicle cannot be predicted in the prior art is solved.

The application relates to a supercavitation vehicle cavitator rudder structure, a vehicle and a control method. The cavitator rudder is arranged at the front end of the vehicle, the whole flow surface is wet, and stable and clear steering torque is provided for the vehicle. The first rotating shaft and the second rotating shaft are arranged orthogonally, the cavitator rudder movement is decomposed into independent yaw and pitch dimensions, the driving mechanism one 5 and the driving mechanism two 6 independently drive corresponding channels respectively, movement interference is eliminated, and steering actions can be executed independently or synchronously. The structure replaces the traditional tail rudder, and tail flow field interference and additional navigation resistance are avoided.

The application discloses an underwater vehicle driven by energy storage compressed gas based on supercavitation drag reduction and a driving method thereof. The application uses a power system of compressed gas expansion to provide power for the underwater vehicle, and meanwhile, waste gas of the power system generates a supercavitation to reduce the drag of the vehicle, so that the traditional lithium battery underwater vehicle power system is replaced. The method of coupling the power system and the drag reduction system increases the compactness of the system, reduces the navigation resistance, effectively improves the navigation speed, the endurance time and the high-speed maneuverability of the underwater vehicle, and good benefits are obtained.

The invention provides a water entry experiment system of an underwater vehicle and an experiment method of the water entry experiment system, and belongs to the technical field of underwater vehicle experiments. Comprising a water tank, a high-speed camera and a launching assembly, the top of the water tank is open, an elastic bullet attaching layer is arranged at the bottom of the water tank, the high-speed camera is arranged beside the water tank, the launching assembly comprises a coil gun launcher and a control unit, and the coil gun launcher comprises a launching support, a gun barrel, a coil, a photoelectric switch and a capacitor; the multiple sections of coils are wound on the gun barrel in the length direction of the gun barrel, each section of coil is correspondingly connected with a capacitor, a photoelectric switch is arranged between every two adjacent coils, the control unit comprises a controller, an external power supply, a boost switch and a silicon controlled trigger switch, and each section of coil is connected with the corresponding capacitor in series through the silicon controlled trigger switch. By optimizing and improving the defects of the traditional experimental device for the supercavitation projectile, the accuracy and reliability of the experiment can be improved.