5 results about "Cavitation flow" patented technology

This invention relates to the field of submerged cavitation water jets, specifically to a method for simulating the flow field load and ice-breaking of submerged water jets considering cavitation effects. The method includes obtaining an initial flow field-ice plate topology model; adjusting the fractal dimension of the mesh through a fractal growth mechanism, fusing a probabilistic model, and embedding a viscoelastic network stress transfer mechanism to obtain a fractal characteristic load field; converting the load generated by fractal iterative loading into the stress and strain of the ice plate, extracting dynamic damage evolution data of the ice plate and chaotic characteristic parameters from the fractal characteristic load field, and obtaining optimized submerged water jet parameters. This invention constructs coupling and correlation rules, clarifying the core coupling relationship between the cavitation-sensitive region and the ice plate load action region, ensuring that the cavitation load is accurately transferred to key areas of the ice layer. By adjusting the fractal dimension of the mesh in real time through a fractal growth mechanism to adapt to the dynamic evolution stage of cavitation bubbles, it solves the problem that traditional models cannot simultaneously capture the cavitation flow field morphology and ice plate damage.

The present application belongs to the technical field of intersection of computational fluid dynamics and artificial intelligence, and in particular to a high-precision prediction method for a hydrodynamic torque converter cavitation flow field. The method comprises the following steps: S1: obtaining transient CFD flow field simulation data inside the guide wheel flow passage of the hydrodynamic torque converter; S2: constructing a multi-task neural network model; S3: constructing a hybrid supervised loss function for optimizing the cavitation prediction sub-network; S4: training the neural network model by adopting a three-stage decoupling strategy; S5: constructing a physical residual loss term based on the law of conservation of fluid dynamics; and S6: inputting the space-time coordinates to be predicted into the trained neural network model. The present application improves the recognition accuracy of sparse cavitation features, enhances the training stability of complex multiphase flow fields, improves the physical consistency of the prediction results, and significantly improves the calculation efficiency of the cavitation flow field.

The present application relates to the technical field of fluid machinery computational fluid dynamics, in particular to a cavitation turbulent large eddy simulation method of nonlinear phase change viscosity correction, in the method, based on the local gas content, the effective dynamic viscosity of the fluid is updated by using a nonlinear hybrid dynamic viscosity empirical formula, the nonlinear hybrid dynamic viscosity empirical formula is used for characterizing additional dissipation generated in the gas-liquid mixing area due to interphase interaction; based on the updated flow field, the sub-grid stress is calculated, and a dynamic coefficient damping formula based on cavitation intensity is introduced to correct the core coefficient of the sub-grid model, and the corrected sub-grid turbulent viscosity is obtained. Through the construction of multiphase flow control equation, dynamic sub-grid modeling, nonlinear property updating and flux reconstruction technology, the simulation accuracy and numerical stability of complex cavitation flow are significantly improved, and a high-precision numerical simulation tool is provided for the design optimization and cavitation suppression of hydraulic machinery such as water turbines, water pumps and propellers.

A cryogenic fluid throttling characteristic visualization experimental device includes: a vacuum chamber and a connected test chamber, a cryogenic visualization module, a cryogenic fluid filling and discharging module, and a data acquisition system. The vacuum chamber is equipped with a coil heat exchanger and a gas-liquid separator for regulating the subcooling and stability of the fluid before throttling. The cryogenic visualization module is mounted on the test chamber, and the throttling test section to be measured is located within the test chamber. The cryogenic fluid filling and discharging module and the data acquisition system are connected to the vacuum chamber and the test chamber, respectively. This invention enables the visualization study of the throttling cavitation flow characteristics of cryogenic fluids such as liquid hydrogen and liquid nitrogen under different operating conditions.

This invention provides a numerical prediction method for cavitation noise in bladed pump-jet propulsion. It conducts steady and unsteady numerical simulations of the internal flow of the bladed pump-jet propulsion, analyzing its hydrodynamic performance and internal flow field. Secondly, it performs numerical simulations of the propulsion's cavitation flow, comparing and analyzing the propulsion's hydrodynamic performance under non-cavitation and cavitation states. It also analyzes the cavitation flow field of the propulsion at different speeds and cavitation numbers, exploring the cavitation evolution law and its dynamic characteristics. Finally, based on the unsteady calculation results of the internal flow of the bladed pump-jet propulsion, combined with acoustic finite element method calculations and spherical cavitation radiation theory, it numerically simulates the noise induced by the cavitation flow inside the propulsion, analyzing the relationship between the propulsion's cavitation flow and its induced cavitation noise. This aims to provide a reasonable and effective prediction method for the numerical prediction of cavitation noise in bladed pump-jet propulsion, possessing significant theoretical and engineering value.