20 results about "Ship hydrodynamics" patented technology

The invention relates to the technical field of numerical simulation ship response, in particular to a ship hydrodynamic response numerical simulation method and system considering the effects of a complex wave field and an automatic mooring system. Firstly, ship radiation potential and hydrodynamic coefficients are obtained based on a three-dimensional potential flow theory and a boundary element method, and wave field information at a berth is obtained in combination with a Boussinesq wave theory; the time domain wave force is solved through the Haskind-Relation theory, and an automatic mooring numerical model integrated with a PD controller is established to calculate the automatic mooring force and torque; and finally, constructing a ship six-degree-of-freedom time domain motion equation based on the data, and solving by adopting a four-order Runge-Kutta method to obtain a time domain response result. The hybrid Boussinesq-Panel technology is adopted, the wave disturbance evaluation accuracy is improved, the blank that existing simulation does not consider an automatic mooring system sufficiently is filled up, arrangement, parameters and control strategies of the automatic mooring device can be flexibly adjusted and secondarily developed, applicability and flexibility are high, and the method is suitable for large-scale popularization and application. And reliable decision support can be provided for procurement and deployment of automatic mooring equipment of a port.

This invention relates to a process architecture for optimizing ship hydrodynamic configurations based on artificial intelligence technology. The architecture includes modules such as expert experience, historical sample data of ship hydrodynamic configurations, design input for ship hydrodynamic configurations, a knowledge base for ship hydrodynamic configuration design and evaluation, a parametric model of ship hydrodynamic configurations, knowledge-driven reconstruction of the ship hydrodynamic model, AI-based optimization design of ship hydrodynamic configurations, rapid evaluation of ship hydrodynamic performance, and a comprehensive evaluation index model for ship hydrodynamic performance. This invention fully leverages the design experience contained in historical sample data, extracting the experience of numerous experts into design knowledge and integrating it into the ship hydrodynamic configuration optimization design process. The process architecture drives intelligent reconstruction of the ship hydrodynamic model through design knowledge, and improves upon the shortcomings of traditional ship hydrodynamic performance prediction methods, such as time consumption and low efficiency, by establishing a rapid prediction proxy model for hydrodynamic performance based on machine learning algorithms.

The application provides a flow field reconstruction and deduction method based on K-A theorem, and belongs to the technical field of ship hydrodynamics. First, multi-dimensional data such as the direction, amplitude, period, frequency and flow velocity of irregular waves are collected and integrated into high-dimensional wave vectors. Then, the KAN network with B-spline curve as a learnable function is used to map the high-dimensional input into a low-dimensional parameter list, obtain the amplitude, angular frequency and initial phase of the dominant equivalent regular wave, calculate the decoupling target function by constructing an equivalent wave superposition model, compare the decoupling target function with the true value to obtain a loss function, and then optimize the network parameters by backward propagation until convergence. Finally, based on the network output parameters, a wave superposition model is constructed to represent the real wave in the form of a series of interpretable regular waves superimposed in time sequence, so that efficient and accurate flow field reconstruction and deduction are realized.

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 application discloses an inland waterway virtual design method based on ship-flow field coupling, comprising the following steps: determining ship information and flow field conditions; the ship information at least comprises a ship type and a ship position; the flow field conditions at least comprise a water flow speed, riverbed information and navigation-obstructing structure information; performing ship hydrodynamic response calculation; performing ship motion trajectory analysis on ships of various ship types, and using analysis results for inland waterway virtual design. In the channel design process, the application fully considers the interaction between the ship and the flow field, can make the ship effectively avoid risk oblique flow and rapid flow, and reasonably utilize water flow kinetic energy, so as to improve the safety and economy of ship navigation.

A method for measuring the hydrodynamic pressure of a bilge keel on a surface ship includes: 1. Determining the main structure and bilge keel structure of a ship model, with a scale ratio of λ, and determining the positions of n measurement nodes located on the lower surface of the bilge keel; 2. Modeling the ship model from step 1 and comparing the strain at each measurement node with the strain at the lower surface of the bilge keel by applying water pressure, and calculating the strain transfer coefficients C1 to C2 corresponding to the n measurement nodes. n 3. Construct the boat model from step 1, and conduct a water immersion test in the test tank to obtain the water velocities V1 to V at n measurement nodes. n The micro-strain με1~με at n measurement nodes was measured. n 4. Obtain the hydrodynamic pressure P at the measurement node of the ship model. i :P i =με i / C i , i = 1, 2, 3…n; V. Obtain the actual ship hydrodynamic pressure SP at the corresponding measurement node positions of the bilge keel on the actual ship. i And the actual ship's entry speed SV i SP i =λ×P i This allows us to obtain hydrodynamic pressure data for the bilge keel under different working conditions, which can be used to assist in bilge keel design and improve the reliability of the bilge keel structure.

The application provides a kind of ship quick current environment under the control method of unberthing pilot operation, it is related to marine engineering equipment technical field.The method obtains ship static parameters and actual draught, generates ship hydrodynamic characteristic tensor;Three-dimensional flow velocity vector data, physical cable real-time tension vector, actual heading angle and actual yaw angle rate are obtained, and the stream velocity scalar and the absolute flow direction angle are extracted;Calculate relative drift angle, solve the original longitudinal force, the original transverse hydrodynamic force and the original yaw torque translated to the first back cable support point position;Based on the original yaw torque, the pre-tightening force threshold and the safe working load, the safety interlocking logic is constructed, the asymmetric uncabling timing instruction and the target external rotation angle rate are generated;The deviation between target and actual angle rate is calculated to generate instruction compensation torque, and the transverse fine-tuning thrust is issued according to the longitudinal force arm of the auxiliary tugboat.The application parasitizes the longitudinal flow force as the unberthing external rotation energy, eliminates the risk of quick current cable breaking and reduces the energy consumption of tugboat.

The invention relates to the technical field of ship automatic control, and discloses a propeller rotating speed fault-tolerant control method and system in a navigational speed keeping scene, and the method comprises the steps: synchronously collecting the physical rotating speed of a propeller, the output torque of a main engine, and the real-time navigational speed of a ship; the soft measurement rotating speed is calculated on line based on the navigational speed and ship hydrodynamic parameters; carrying out fusion observation on the two paths of rotating speed signals by utilizing a self-adaptive sliding mode observer, and generating a system state observation value and a lumped disturbance observation value; the hard fault of the sensor is reliably diagnosed based on the logic that the double residuals continuously exceed the threshold value by calculating the physical measurement value and the residual error of the two; after definite diagnosis, smoothly switching a closed-loop feedback signal to a soft measurement value to generate a fault-tolerant arbitration rotating speed; and finally, feedforward and feedback compound control is carried out based on the rotating speed deviation in combination with a disturbance observation value, and a driving instruction is generated. According to the method, the continuous and stable operation of the navigational speed control loop can be maintained when the rotating speed sensor has a hard fault without hardware redundancy.

The application discloses a kind of based on improved model predictive control unmanned ship trajectory tracking control method and device.The method includes, H-PINN method is introduced into unmanned ship hydrodynamics model, obtains the simplified hydrodynamics model of unmanned ship;Based on the prediction model of the trajectory tracking of unmanned ship obtained in simplified hydrodynamics model, the expected trajectory and control quantity of model predictive control MPC are designed using differential flatness theory, and stability analysis is designed according to Lyapunov function.The method improves model predictive control using differential flatness theory, and Lyapunov function optimization analysis is combined, improves trajectory tracking precision, reduces the change amplitude of control quantity, so that the speed change in navigation process is more smooth.

This invention discloses a time-domain numerical method for calculating the hydrodynamic performance of ships in the field of marine hydrodynamics. The method includes: establishing a three-dimensional numerical model of the hull and free surface; decomposing the total velocity potential based on time-domain potential flow theory; constructing boundary integral equations; introducing a time-increasing monotonically increasing function to smooth the initial transient response; simultaneously iteratively solving the free surface evolution and the ship's six-degree-of-freedom motion equations; and achieving self-consistent coupling between flow field pressure and ship motion using a closed feedback loop. This method also supports nonlinear free surface boundary conditions, suppresses numerical dissipation through high-order extrapolation, and dynamically calculates the restoring force matrix based on surface element integrals, significantly improving the calculation accuracy and stability of ship motion response in confined waters. It is suitable for engineering prediction of complex conditions such as near-shore navigation, shallow water resonance, and shoreline reflection.

The application provides a rudder ball thrust fin capable of rotation and release, and belongs to the field of ship hydrodynamic energy-saving devices. The rudder ball thrust fin can solve the problem that the resistance generated by the existing rudder ball thrust fin during the high-speed sailing of a ship can exceed the propulsion benefit, which will lead to the increase of the overall resistance, and thus the energy-saving effect of the rudder ball thrust fin is lost. The rudder ball thrust fin comprises a rudder body, an integrated rudder ball, a thrust fin, an integrated rudder blade, a rudder ball rotating mechanism and a rudder blade rotating mechanism. The integrated rudder ball is provided with the thrust fin on both sides. The integrated rudder ball is rotationally arranged on the rudder body. The rudder body is provided with a thrust fin groove at the upper end and the lower end of the integrated rudder ball. The two thrust fins are respectively embedded in the two thrust fin grooves. The integrated rudder blade is rotationally arranged on the outer side of the thrust fin groove. The rudder ball thrust fin is mainly used for ship hydrodynamic energy-saving devices.

The invention provides a flow field reconstruction and deduction method based on the K-A theorem.The method belongs to the technical field of ship hydrodynamics, and comprises the steps that firstly, multi-dimensional data such as the direction, the amplitude, the period, the frequency and the flow speed of irregular waves are collected and integrated into a high-dimensional wave vector, and then a KAN with a B spline curve as a learnable function is used for obtaining a high-dimensional wave vector; high-dimensional input is mapped into a low-dimensional parameter list, the amplitude, the angular frequency and the initial phase of dominant equivalent regular waves are obtained, a loss function is obtained by constructing an equivalent wave superposition model, calculating a decoupling objective function and comparing the decoupling objective function with a true value, then network parameters are optimized through back propagation until convergence, and finally, the optimal network parameters are obtained. A wave superposition model is constructed based on network output parameters, real waves are represented in the form that a series of interpretable regular waves are superposed on a time sequence, and efficient and accurate flow field reconstruction and deduction are achieved.

The invention relates to the field of ship hydrodynamics and numerical simulation, and discloses a giant estuary ship navigation capability numerical simulation model test method, which comprises the following steps: executing a prospective preparation step, and constructing a baseline physical model; executing a baseline simulation and dynamic risk assessment step, performing navigation simulation under the driving of the baseline physical model, and calculating a dynamic risk potential field value in real time; when the dynamic risk potential field value exceeds a trigger threshold value, executing a high-fidelity instantiation step, and activating a high-fidelity physical kernel module; an asynchronous coupling calculation step is executed, and the accurate hydrodynamic force calculated by the high-fidelity module is used for replacing a ship body hydrodynamic force item in the baseline ship control model; when the dynamic risk potential field value is continuously below a degradation threshold, a model degradation step is performed, and calculation of its inherent hull hydrodynamic terms by the baseline ship manipulation model is resumed. By means of the dynamic switching mechanism, high-precision computing resources are only input in a necessary high-risk section, and efficient simulation is maintained in a low-risk section.

The invention discloses a large-load thrust and torque sensor and a design, bridging and calibration method, and relates to the field of ship hydrodynamic force measurement tests. The problem that in the prior art, huge thrust and torque cannot be measured synchronously and directly with high precision in a real ship test of a ship propeller is solved. Comprising a driving source shaft, a thrust torque balance element, a propeller shaft, a protective cover and the like. The structural rigidity is large, the thrust torque sensor can carry out sensitive element sensitivity design according to propeller thrust torque design indexes, the requirement for measurement accuracy is met, the thrust torque balance element is integrally machined by high-strength steel, and the thrust torque balance element is made of high-strength steel through a special bridging mode. And the signal output interference of an interference source on the thrust element and the torque element can be reduced. The device has a good application prospect in the field of ship hydrodynamic force measurement tests.

The application discloses a device suitable for measuring roll excitation moment of a ship model loaded with fluidized cargo in the technical field of ship hydrodynamics test and ship model test technology, and comprises a pool trailer system, a wave generator and a measuring model, wherein the measuring model comprises a ship model, an inner frame and an outer frame, the bow and the stern of the ship model are provided with adjustable connecting devices rigidly connected with the end of the ship body, the adjustable connecting devices comprise flanges, the flanges comprise a bow flange and a stern flange, the bow flange and the stern flange are fixedly connected with the bow and the stern of the ship model respectively, and the bow flange and the stern flange can adjust the relative height thereof with the ship model through sliding grooves; the device further comprises rotating shafts and torque sensors, the rotating shafts comprise a bow rotating shaft and a stern rotating shaft, and the inner side of the inner frame is fixedly provided with the torque sensors at both ends, and the device can accurately measure the roll excitation moment of the ship model loaded with fluidized cargo in the seakeeping test through cooperation of the inner frame and the outer frame.

The application discloses a trimaran motion and wave load calculation method considering strong nonlinear load, and relates to the field of ship hydrodynamic performance calculation. The method solves the problems that the traditional potential flow method is inaccurate in predicting strong nonlinear phenomena such as slamming and large amplitude motion, and the full viscous flow method is too high in calculation cost by coupling potential flow theory and viscous flow theory. The core comprises the following steps: a motion equation framework considering instantaneous wet surface change is constructed based on three-dimensional time domain potential flow theory; a viscous flow CFD method is used to accurately quantify the slamming load and identify the nonlinear damping caused by the entry and exit of a piece into water; and one-way / weak coupling is performed between a parameterized database and a potential flow model, so that the nonlinear load parameters are fed back to the motion equation for correction and rapid solution. The application considers both accuracy and efficiency, and is suitable for engineering design and analysis of various trimarans.

This invention provides a numerical calculation method and system for inter-ship effects during the lateral replenishment approach phase of two ships based on CFD-MMG coupling, belonging to the field of ship hydrodynamic numerical simulation technology. The method includes: constructing an MMG ship motion mathematical model; acquiring the dynamic response time history data of the ship from start-up to stable navigation; and determining the stable navigation time based on the response convergence criterion; constructing a segmented adjustment strategy based on state event triggering, using propeller speed as the control input; reconstructing unsteady velocity and displacement data segmentally under overall relative displacement constraints, and adjusting the trajectory according to the navigation phase to achieve spatial closed-loop control of the two ships from overtaking to parallel operation; constructing a continuous-time velocity function to drive ship motion based on the segmented reconstruction results, while maintaining physical consistency and continuity; embedding the continuous velocity function into CFD numerical calculation, and using an overlapping grid method to simulate the relative motion of the two ships from overtaking to parallel operation, thereby obtaining the inter-ship hydrodynamic and flow field evolution results.

The invention discloses a double-ship cooperative operation coupling dynamic positioning cooperative control method, which comprises the following steps of: establishing an adjacent ship hydrodynamic model through a numerical simulation and experiment combined method; based on the adjacent ship hydrodynamic model, designing a coupling dynamic positioning control algorithm, taking the motion state of the double ships and the adjacent ship hydrodynamic interference as input, and calculating and adjusting the thrusts and torques of the propellers of the double ships in real time through a control law combining a state feedback control law and a feedforward control law; a cooperative control strategy is formulated, relative position and attitude constraint conditions are introduced, control targets of the two ships are dynamically adjusted according to operation requirements, and mutual interference of movement of the two ships is avoided; a self-adaptive adjustment mechanism is adopted, and parameters of a control algorithm are adjusted in real time according to the actually measured ship motion state and environment parameters so as to adapt to different operation conditions and environment changes. According to the method, the dynamic positioning performance of the double ships is guaranteed, and the safety and efficiency of collaborative operation of the double ships are improved.

The application discloses a ship free surface wave form prediction method based on a neutral grid, relates to the field of ship hydrodynamics, and determines a grid step according to the maximum sample speed in the numerical simulation process of a ship at different sample speeds, generates a two-dimensional neutral grid irrelevant to the speed as a same space reference system and topology, projects a steady free surface elevation field at different speeds on the two-dimensional neutral grid to obtain a labeled elevation to train a wave form prediction model, inputs a target speed and a to-be-predicted feature constructed by grid coordinates of the same two-dimensional neutral grid in a model inference stage, and thus the free surface wave form prediction result of the arbitrary target speed under the draft can be obtained. The method can realize consistent alignment and rapid prediction of wave form data at different speeds under a specific draft, enables the model to directly output a steady three-dimensional free surface under an unknown draft and an unknown speed, and realizes rapid and stable prediction of the free surface wave form across the speed.

The invention discloses a ship gas layer drag reduction flow field numerical simulation method and device and a medium, and relates to the technical field of ship hydrodynamic simulation calculation. The method comprises the following steps: constructing a simulation calculation domain of a real-scale ship gas layer drag reduction flow field, and generating an unstructured grid in the simulation calculation domain to obtain a target to-be-processed model; positioning the boundary of the blowhole in the target to-be-processed model by using the position of the real-scale ship blowhole; calculating flow field analysis key data according to an initial boundary condition of a gas injection hole surface set on the boundary of the gas injection hole in the target to-be-processed model, a boundary condition set on the basis of a real-scale ship simulation working condition and a target viscous Newtonian fluid equation, and performing ship gas layer flow field analysis according to the flow field analysis key data. According to the technical scheme provided by the embodiment of the invention, the two-phase flow field under the specified working condition can be accurately simulated, and the balance between the simulation reliability and the calculation efficiency is realized.