11 results about "Radiation damping" patented technology

The invention discloses a hydrodynamic analysis method for a floating structure with multi-body and multi-coupling characteristics, which comprises the following steps of: acquiring geometric characteristics of each floating body, and dividing boundary element computational grids; wave excitation force, additional mass and radiation damping of each floating body are calculated, and a mass matrix and a rigidity matrix of each floating body are obtained; determining a connection mode and a coupling factor of the floating body; according to a connection mode and coupling characteristics of the system, establishing displacement connection conditions among the floating bodies; constructing a motion constraint matrix according to the displacement continuity condition and the motion constraint relation; determining a frequency domain motion equation of the multi-floating-body system according to a Lagrange multiplier method; and solving the motion equation to obtain the motion response of the multi-floating-body system, and further systematically analyzing the wave energy capture power according to the coupling characteristics of the system. According to the analysis method, the problem that the motion response of each degree of freedom cannot be accurately described when the hydrodynamic response characteristics of the complex multi-body system are obtained through an existing simulation method is solved.

This application discloses an offshore floating semi-submersible platform and an offshore power generation system. The offshore floating semi-submersible platform provided by this application includes a platform body equipped with wind turbine components and photovoltaic components to achieve wind and solar complementary power generation. A heave assembly is provided below the platform body, which includes at least two different sizes of heave plates and forms at least two moon pool structures, which together constitute a damping coupling system. The differentiated heave plates provide a graded response to broadband waves, and the moon pool structure adds additional mass and radiation damping, thereby continuously consuming wave energy, significantly reducing the platform's heave response, and improving operational stability. The photovoltaic components include fixed photovoltaic panels and telescopic photovoltaic panels. The fixed photovoltaic panels are located on the top surface of the platform body, and the telescopic photovoltaic panels can switch between a retracted state and an extended state, effectively increasing the photovoltaic power generation area and improving power generation efficiency.

According to the method, a multi-modal analytical model with the effects of surface waves and internal waves is established aiming at the density stratification phenomenon caused by gravity settlement and solar radiation heat effect in ocean engineering; a three-dimensional layered fluid global control equation set is constructed, a hyperbolic function combined vertical characteristic function piecewise expression is adopted to accurately characterize fluid bimodal propagation characteristics, a double-layer fluid bimodal dispersion equation is combined, a multi-body coupling matrix equation is introduced to process an inter-column wave scattering effect, and a multi-body coupling matrix equation is introduced to process the inter-column wave scattering effect. Cylindrical wave function coordinate transformation is realized by applying a Graf addition theorem, and a hydrodynamic integral expression containing additional mass and radiation damping is constructed based on a modal superposition principle. According to the method, the limitation of a traditional single-layer fluid model is broken through, the wave interference energy distribution rule under the surface wave-internal wave combined action is quantitatively analyzed, and the radiation force calculation precision and the engineering prediction applicability of the dense cylinder array in the complex marine environment are remarkably improved.

The invention discloses a preparation method of a material with a plasmon array and the material. The method comprises the steps that based on a preset nickel female template, imprinting is carried out on a pretreated first original metal sheet; performing anodic oxidation on the first surface of the first original metal sheet to prepare an initial mask plate with an anodic oxidation layer; performing reprocessing on the initial mask plate so as to remove redundant materials on the first original metal sheet under the condition of protecting the anodic oxide layer, thereby obtaining the mask plate; and on the basis of a mask plate, imprinting is performed on the preprocessed second original metal sheet, and the material with the plasmon array is prepared. The material with the array period distance equivalent to the resonance wavelength and coupled with the Bloch wave can be prepared in a secondary imprinting mode, it can be guaranteed that the uniformity and stability of the photon local area are improved under resonance, in addition, the material can inhibit radiation damping through surface plasmon resonance, photons are strongly localized at the nanoscale, and the performance of the material is improved. Therefore, the interaction between the light and the substance is enhanced.

This invention discloses a method for analyzing the dynamic response of a multi-section, multi-compartment, damaged floating bridge under load. The method dynamically updates the liquid level in each compartment, the mass of water entering the compartment, its center of mass, and the change in moment of inertia of the bridge sections caused by water ingress, based on the size and location of the breach. After determining the position and inclination angle of each bridge section in a stable equilibrium state in still water, the method calculates the generalized added mass coefficient, radiation damping coefficient, and wave excitation force of the floating bridge system under water ingress conditions based on potential flow theory. Finally, it uses the multi-body time-domain hydrodynamic analysis equations to analyze the dynamic response of the damaged floating bridge under load. This invention constructs a theoretical framework for the dynamic response analysis of a damaged floating bridge in still water using multi-body dynamics methods, constructs a multi-section, multi-compartment water ingress model using the modified Bernoulli equation, and then uses potential flow theory to conduct time-domain hydrodynamic analysis, achieving efficient dynamic response prediction and improving calculation accuracy and efficiency.

The invention discloses a high-precision seismic fluctuation input method and device for SSI analysis of a layered stepped site, and the method comprises the steps: building a two-dimensional stepped layered site model, and introducing a Y-shaped artificial boundary to divide the two-dimensional stepped layered site model into a central finite field, a left half infinite field and a right half infinite field; applying a zigzag-paraxial combined boundary on the Y-shaped artificial boundary to simulate the radiation damping effect of the left half infinite domain and the right half infinite domain; respectively solving the seismic response of the one-dimensional horizontal layering field models of the left half infinite domain and the right half infinite domain, and obtaining the free field response of the left boundary and the right boundary of the Y shape through time delay calculation; respectively decomposing respective total field responses into scattered field responses and free field responses, calculating respective infinite domain equivalent node forces and free field node forces according to the scattered field responses and the free field responses, superposing the infinite domain equivalent node forces and the free field node forces to form two groups of final equivalent node force vectors, and respectively applying the two groups of equivalent node force vectors to the left boundary and the right boundary to obtain a final equivalent node force vector. And high-precision input of far-field vibration in layered stepped field SSI analysis is realized.

The invention discloses a through-load floating bridge dynamic response analysis method considering multi-bridge-section and multi-cabin damage water inflow. The method comprises the following steps: dynamically updating the liquid level height in a cabin, the water inlet mass and the mass center position of the cabin, bridge section rotational inertia change caused by water inlet and the like according to the crevasse size and position of each cabin, and determining the position and inclination angle of each bridge section when the multi-bridge-section and multi-cabin damaged water inlet floating bridge in still water is in a stable and balanced state; the generalized additional mass coefficient, the radiation damping coefficient and the wave exciting force of the floating bridge system in the water inlet state are calculated based on the potential flow theory, and dynamic response analysis of the broken cabin floating bridge in the loading state is conducted through a multi-floating-body time domain hydrodynamic analysis equation. According to the method, a dynamic response analysis theoretical framework of the still water cabin breaking floating bridge is constructed through a multi-body dynamics method, a multi-bridge-section and multi-cabin water inlet model is constructed in combination with the corrected Bernoulli equation, time-domain hydrodynamic analysis is carried out through the potential flow theory, efficient dynamic response forecasting is achieved, and the calculation precision and efficiency are improved.

The application discloses a kind of multi-body multi-coupling characteristics of floating structure hydrodynamic analysis method, comprising the following steps: obtaining the geometric characteristics of each floating body, dividing boundary element calculation grid;Calculate each floating body wave exciting force, additional mass and radiation damping, obtain the mass matrix and stiffness matrix of each floating body;Determine the connection mode and coupling factor of floating body;According to the connection mode and coupling characteristics of system, establish the displacement connection condition between each floating body;According to displacement continuous condition and motion constraint relationship, construct motion constraint matrix;According to Lagrange multiplier method, determine the frequency domain motion equation of multi-floater system;Solve motion equation, obtain the motion response of multi-floater system, according to the coupling characteristics of system, further system's analysis wave energy capture power.According to the above analysis method, the present application can solve the problem that the existing simulation method cannot accurately depict the motion response of each degree of freedom when obtaining the hydrodynamic response characteristics of complex multi-body system.

The invention provides a semi-submersible wind power platform with a concave heave plate structure. The semi-submersible wind power platform comprises a plurality of buoyancy units, a plurality of supporting mechanisms, an anchor chain and a fan. The multiple buoyancy units and the multiple sets of supporting mechanisms are sequentially and alternately arranged to form the annular space frame structure, and the whole platform has good stability and rigidity. In each buoyancy unit, a heaving plate is installed at the bottom of a buoy, meanwhile, the scheme innovatively provides an inwards-sunken cavity formed in the surface of the heaving plate, a local high-pressure area and a stable backflow vortex field are formed in the structure in an induced mode through the acceleration, compression and expansion effects of fluid in the cavity, radiation damping and heaving additional mass are remarkably enhanced, and the effect of the heaving effect is achieved. A hydrodynamic regulation and control mechanism that flow is controlled through shapes and energy is efficiently consumed is achieved, the motion inhibition capacity is effectively improved, and the overall projection area of the heaving plate does not need to be enlarged. Through the arrangement, the semi-submersible floating platform effectively controls the construction cost on the premise of ensuring the structural stability.

The invention relates to the technical field of ocean engineering, and discloses an energy dissipation floating breakwater with a resonance type cavity and a hydrodynamic performance analysis method of the energy dissipation floating breakwater. Respectively determining target lengths and target widths of the resonant cavity, the wave head side perforated wave dissipation chamber and the wave back side perforated wave dissipation chamber; the whole fluid domain of the floating breakwater is divided into a plurality of areas; solving the speed potential of each region; calculating the wave force of the floating breakwater, and expressing the additional mass and radiation damping when the floating breakwater performs unit forced oscillation by utilizing the speed potential of each region so as to construct a motion response equation of the floating breakwater in a frequency domain under the action of waves; the transmission coefficient and the energy dissipation coefficient of the floating breakwater are obtained through the equation set, and the shielding performance and the wave dissipation performance of the floating breakwater are evaluated according to all the coefficients. The cooperation of the resonant cavity and the perforated wave dissipation chamber can improve the wave dissipation efficiency, and the analysis method can provide an efficient and reliable basis for the design of the breakwater.

This invention discloses a blade-shaped high-efficiency wave energy generation device, comprising a wave-absorbing float, which is integrally blade-shaped, including a flat plate portion and an arc-shaped portion disposed on the back of the flat plate portion; the flat plate portion of the wave-absorbing float is used to drive the power generation equipment to perform work; a support truss is connected and installed at one end in the arc-shaped portion, and the other end is hinged to a support base. Under the action of an incident wave, the blade-shaped wave-absorbing float receives the excitation of the incident wave and undergoes pitching motion, driving the hydraulic cylinder to perform work. At the same time, the wave-absorbing float begins to rotate around the hinged rotation support point. Due to its arc-shaped back, the pitching does not generate waves and does not produce radiation damping to dissipate energy; secondly, because the blade-shaped wave-absorbing float is lightweight, it requires less energy to rotate. Most of the work done by the wave-acting float is captured by the PTO energy conversion system, improving the energy capture efficiency of the wave energy device.