12 results about "Hydrodynamic forces" patented technology

A distributed high-fidelity simulation system for large-scale high-speed AUVs based on real disturbance data is proposed. Through a large-scale AUV virtual test vehicle subsystem, the system simulates the motion state of a real large-scale high-speed AUV physical prototype under the interaction of rigid body inertia, gravity, buoyancy, inertial hydrodynamic forces, centripetal force, Coriolis force, drag, thrust, rudder force, and external environmental disturbances. Collision attributes are added to the prototype through a physics engine. The system also utilizes an underwater 3D virtual environment subsystem to render a large-scale underwater environment, build dynamic and static obstacle visualization models, and simulate the generation of realistic ocean currents and wave disturbances with high fidelity. The simulation presents a realistic underwater environment for a large, high-speed AUV. A motion solution subsystem describes the transformation relationships between the fixed coordinate systems of all objects in the underwater virtual environment and solves the motion equations of the large AUV, synchronously updating its pose and velocity states. A data management subsystem manages various data generated during the simulation, supporting write and read data operations, and also manages and coordinates data communication between nodes, supporting receive and send data operations. A visualization subsystem loads and dynamically displays the underwater 3D environment and the large AUV virtual test vehicle model, synchronously updating real-time data curves and visualizing the AUV's motion trajectory.

The end faces of bearings feature slots in a transition zone. These slots improve the balance of hydrostatic and hydrodynamic forces between the bearing and a gear mounted on a journal supported by the bearing, thereby increasing film thickness and providing higher force at smaller distances. The slots also reduce end face wear caused by operating the gear pump under higher pressure conditions.

The present invention provides a tsunami shelter that can be constructed with little time, effort, or cost of a structure, and capable of protecting human life with a high probability from occurrence of a tsunami until a predetermined time has elapsed.　The tsunami shelter includes a shelter body 2, at least an upper portion of which is sealed to secure a living space S therein, and an outer wall portion 3 surrounding the periphery of the shelter body 2 and interfering with at least mechanical effects on the shelter body 2 caused by hydrodynamic forces or drifting objects generated by a tsunami. The outer wall portion 3 is supported by the ground or the like, and the shelter body 2 and the outer wall portion 3 are formed as separate structures.

This invention belongs to the technical field of subsea pipeline structure stress and in-situ stability. It discloses a model pipeline system capable of accurately measuring the stress on subsea pipelines. The system has a symmetrical structure and includes a model pipeline body, end support structures, a two-dimensional total force sensor measurement assembly, a dynamic pressure measurement sensor, a maintenance window for the model pipeline system, fixed tie rods, and a pressure sensor mounting body. The pressure sensor mounting body is located between the two model pipeline bodies. This invention can highly integrate various sensors into the same model pipeline testing system, greatly improving experimental testing efficiency. Furthermore, this invention enables simultaneous measurement of the hydrodynamic forces and soil resistance experienced by the model pipeline, making research on the in-situ stability of subsea pipelines a practical possibility.

The present application belongs to the field of ship hydrodynamics and motion prediction, and in particular to a device and method for predicting the hydrodynamics and motion of a ship coupled with ice, which first derives a Green function that satisfies the boundary conditions of the ice layer and the free surface, as well as all other conditions except the surface condition of the ship, and through the Green function, the differential equation of the velocity potential is converted into a boundary integral equation on the surface of the ship only, which introduces an extended surface at the waterline of the ship body to eliminate the influence of irregular wave frequencies; an asymptotic solution formula of the Green function is analytically derived, thereby establishing an approximate and effective solution program for the coupled interaction of the ship / wave / ice layer, and numerically calculating the results of the added mass, damping coefficient and wave exciting force of the ship body; through the method, the interaction mechanism of the water wave / ship / ice layer under different parameter characteristics can be deeply understood, and theoretical support is provided for the hydrodynamic problems, motion prediction and rational design of polar ships.

The invention provides a hot water force multi-field monitoring analysis method and system suitable for a TEHB test system, and the method comprises a model framework building step, a steady-state initial field solving step, a hot water force coupling solving step, and a multi-field response data collection and recording step. The invention further provides a hot water force multi-field monitoring and analyzing system suitable for the TEHB test system, a three-dimensional model containing the six-direction waveguide rod and the rock sample is established, a mechanical, seepage and temperature steady-state initial field before impact loading is obtained, hot water force coupling dynamic calculation is carried out under the action of triaxial six-direction synchronous impact, and the test result is obtained. And curves and statistical indexes of key results such as stress, fracture, pore pressure, temperature and the like are automatically output. According to the invention, the impact process simulation can be realized under the hot water-force coupling loading condition, and multi-field response data can be monitored and analyzed, so that the dynamic mechanical behavior of the rock under the hot water-force coupling effect can be revealed, and a basis is provided for the scientific design of deep engineering.

Slots are provided in the end faces of the bearings in a transition region. The slots improve the balance of hydrostatic and hydrodynamic forces between the bearing and a gear mounted on a journal supported by the bearing, thus increasing the film thickness and providing greater strength at smaller clearances. The slots reduce wear on the end face resulting from the operation of the gear pump under higher pressure conditions. (Shortcut figure: Fig. 5)

The invention discloses an underwater follow-up rotating towed body for integrated navigation. Comprising an external follow-up housing, stabilizing wings, a fixed frame, a rolling bearing and a combined navigation assembly, the outer surface of the external follow-up housing is connected with a stabilizing wing; a combined navigation assembly and a fixed frame which are coaxially arranged from inside to outside are arranged in the external follow-up housing, and the upper end and the lower end of the combined navigation assembly are rotationally connected with the fixed frame through rolling bearings respectively; the fixed frame is fixedly connected with the external follow-up housing, and the combined navigation assembly is electrically connected with the outside; when the external follow-up housing is placed underwater, the external follow-up housing freely rotates around the central shaft under the action of hydrodynamic force, and the rotating motion of the external follow-up housing is decoupled by the rolling bearing, so that the external follow-up housing and the fixed frame can rotate relative to the combined navigation assembly, and the combined navigation assembly is kept in a stable state. The structure is ingenious, the problem that the navigation precision of a traditional towed body is greatly disturbed by fluid is effectively solved, and the reliability and stability of underwater long-endurance and high-precision navigation are remarkably improved.

This invention discloses a simulation method and system for ship berthing and unberthing maneuvering considering the combined effects of wind and waves. The method establishes a body-dependent coordinate system with the ship's center of gravity as the origin, constructs three-degree-of-freedom motion equations for the ship's sway, roll, and bow roll in the horizontal plane, and couples the ship's hydrodynamic forces, propeller forces, rudder forces, bow thruster forces, wind loads, current loads, and wave drift forces into the state model. Wind loads are calculated using the wind pressure coefficient method, current loads using the current pressure coefficient method, and wave drift forces are obtained through frequency domain integration of the random wave spectrum and the drift force transfer function. Based on the aforementioned maneuvering forces and environmental forces, the state vector is solved iteratively using the fourth-order Runge-Kutta method, updating the ship's position coordinates, heading angle, and velocities in each direction in real time, and outputting the time histories of environmental forces and maneuvering forces to support berthing and unberthing maneuvering decisions. This invention features complete environmental load modeling, high numerical solution accuracy, and a modular system structure, demonstrating good engineering applicability.

This application provides a jet modulation suppression method and system for chatter suppression in bearing roller grinding. The method includes: performing time-frequency analysis on the vibration acceleration data during the pre-processed bearing roller machining process to obtain a target suppression frequency set; obtaining an adaptive modulation signal sequence based on the frequencies and corresponding phases in the target suppression frequency set; obtaining a desired valve opening area sequence for controlling the jet switching valve based on the principle of canceling out the target damping force and the jet impact force; compensating for the inertial delay of the driving voltage at the previous time stamp based on the desired valve opening area sequence to obtain a compensated driving voltage; obtaining a jet duty cycle sequence based on the compensated driving voltage sequence, and then obtaining the control signal for controlling the jet switching valve. This application achieves precise cancellation of the hydrodynamic forces opposite to the chatter by real-time sensing of chatter characteristics and utilizing active pulse jets, improving machining stability and consistency, and is suitable for the mass precision manufacturing of high-performance bearing rollers.

The present invention relates to a downhole cable tool for performing operations in a metal well tubular structure downhole of a well containing wellbore fluid, the downhole cable tool having an axial extension direction and a front face facing away from the top of the well, and the downhole cable tool comprising: a cable connection unit for connecting to a cable; an electric motor powered by the cable for rotating the rotating shaft at a first rotational speed; an operating tool component for performing an operation by electric and / or hydraulic fluid; and an epicyclic gear arranged between the electric motor and the operating tool component, the epicyclic gear being driven by a rotational shaft of the electric motor for rotating the operating tool component at a second rotational speed through the output rotational shaft, the epicyclic gear having a channel through which an electrical and / or fluid line extends, to provide electrical and / or hydrodynamic forces for operating the operating tool component. The invention also relates to a downhole system comprising a downhole cable tool and a drive unit, such as a downhole tractor, for advancing the downhole system in a well.

Slots are provided in end faces of bearings in a transition region thereof. The slots improve the balance of hydrostatic and hydrodynamic forces between the bearing and a gear provided on a journal supported by the bearing, thereby improving film thickness and providing increased force at smaller clearances. The slots reduce wear occurring on the end face resulting from operation of the gear pump under higher pressure conditions.