19 results about "Flow instability" patented technology

The invention discloses a hypersonic flow instability multi-field coupling prediction method and system, and relates to the technical field of modern high-speed aircraft design, and the method comprises the steps: obtaining the multi-physical field parameter distribution of a hypersonic flow field; based on a shock wave-boundary layer interaction mechanism, constructing an instability sensitive graph data structure by taking multi-physical field parameters as input, setting graph nodes in a shock wave influence region, a boundary layer region and an intersection region thereof, and calculating connection weights among the nodes; performing multi-scale decomposition on the instability sensitive graph data structure, and extracting instability modes of a shock wave scale, a vortex scale and a molecular scale; screening the instability modes by adopting a hypersonic velocity stability criterion, and determining a dominant instability mode; and constructing an instability evolution prediction model based on the dominant instability mode, and outputting a spatio-temporal evolution rule of hypersonic flow instability. According to the method, the problem that the flow instability phenomenon in the hypersonic velocity complex multi-physical field environment is difficult to accurately predict can be solved.

The application discloses a hypersonic flow instability multi-field coupling prediction method and system, relates to the technical field of modern high-speed aircraft design, and comprises the following steps: acquiring the multi-physical field parameter distribution of a hypersonic flow field; based on a shock wave-boundary layer interaction mechanism, constructing an instability sensitive graph data structure by taking the multi-physical field parameters as input, setting graph nodes in the shock wave influence area, the boundary layer area and the intersection area thereof, and calculating the connection weight between the nodes; performing multi-scale decomposition on the instability sensitive graph data structure, and extracting instability modes of the shock wave scale, the vortex scale and the molecular scale; screening the instability modes by adopting a hypersonic stability criterion, and determining a dominant instability mode; and constructing an instability evolution prediction model based on the dominant instability mode, and outputting the spatiotemporal evolution law of the hypersonic flow instability. The application can solve the problem that the flow instability phenomenon under the complex multi-physical field environment of hypersonic speed is difficult to accurately predict.

The present invention discloses a method for analyzing flow instability models in multi-loop natural circulation systems, relating to the field of nuclear reactor safety technology. The key technical aspects of the method include: establishing a multi-loop natural circulation flow system model; utilizing a self-programming program to perform natural circulation calculations to obtain a bifurcation characteristic curve for a two-phase multi-loop natural circulation flow system; establishing a multi-loop pressure drop-flow equation set with strong flow-heat transfer coupling to obtain a parameter response curve for the two-phase multi-loop natural circulation flow system; and analyzing the influencing characteristics of system parameters using the bifurcation characteristic curve and the parameter response curve. Based on the extraction of a three-loop coupled natural circulation flow system from marine nuclear power source design, the present invention utilizes a self-programming program to perform natural circulation calculations for a two-phase multi-loop system. By screening factors influencing the natural circulation flow of each loop and the heat transfer between loops, the method is used to accurately analyze the influencing characteristics of parameters within a nonlinear multi-loop natural circulation system.

The present application relates to the technical field of flow control, in particular to a material transportation device for road and bridge construction and a flow control method. The method divides a flow unstable period by flow change, evaluates flow irregularity by combining flow rate and pressure data, and determines a problem monitoring point. The method dynamically allocates control weights of the moment by analyzing the instability influence degree of the unstable period itself, and the distribution of the problem point and the trend of flow irregularity. Finally, the flow is controlled by weighting. The present application analyzes the influence caused by blockage and segregation in the flow unstable period of concrete, strengthens the response of the control system by adapting the control weight of each moment, improves the accuracy of the control system, ensures the stable transportation of concrete, and ensures the quality of concrete transported to the pouring point.

This invention relates to the field of glue-filling production technology and discloses a method and system for early warning of defects in the glue-filling process. This invention extracts structural constraint features from product structural data, thereby quantifying abstract product drawings or model information into quantitative engineering parameters that can be analyzed in conjunction with glue-filling process parameters. Simultaneously, it constructs and calculates in real time values ​​for flow instability tendency, venting difficulty, process disturbance intensity, and simulates an evolution curve representing the instantaneous net propulsion capability of the filling process, among other multi-dimensional risk indicators. This allows for the keen detection of complex risks that are about to occur within traditional safety thresholds but due to the synergistic deterioration of multiple process and material parameters in unfavorable ranges. It solves the problems of low accuracy and unclear intervention direction of traditional methods, achieving a qualitative leap from post-event alarms to pre-event warnings and defect attribution, providing a clear direction and valuable time window for process early warning intervention.

The invention provides a focused water jet injection enhancing device based on the coanda effect. Comprising an enhanced ejector, a main pump, an auxiliary pump, a main pump diverter valve, an auxiliary pump diverter valve, a five-way valve and a water tank. The main pump provides high-pressure water flow to drive the enhanced ejector to generate high-speed water flow, the auxiliary pump provides low-speed water flow and distributes the low-speed water flow to the enhanced ejector through the five-way valve, contact between the high-speed water flow and the inner wall of the nozzle is reduced, and the influence of a boundary layer is eliminated. The enhanced ejector comprises a water inlet connecting pipe, a flow stabilizer and a Coanda flow guide nozzle, the flow stabilizer guides water flow through an axial flow guide rib plate, and vortex and flow instability are reduced; the coanda flow guide nozzle guides water flow to stably flow along the inner wall of the nozzle through the coanda effect, the jet divergence angle is reduced, and the jet concentration ratio and the energy density are enhanced. The inner flow channel of the enhanced ejector is combined with the cycloid flow guide area, the straight column flow guide area and the contraction flow guide area, and by optimizing the dynamic behavior of water flow, vortex and instability are reduced, and the stability and impact force of jet flow are improved.

The invention relates to the technical field of flow control, in particular to a road and bridge construction material transportation device and a flow control method. According to the method, flow unstable time periods are divided through flow changes, flow velocity and pressure data are combined to evaluate flow irregularity, and problem monitoring points are determined; dynamically distributing the control weight of the moment by analyzing the instability influence degree of the unstable time period and the distribution and flow irregularity trend of problem points; and finally, performing flow control through weighting. According to the method, the influence caused by blockage and segregation in the period of unstable concrete flow is analyzed, the response of the control weight reinforcement control system at each moment is self-adapted, the precision of the control system is improved, and the quality of the concrete transported to a pouring point is guaranteed while stable transportation of the concrete is guaranteed.

The invention provides a propeller phase synchronous measurement device and method based on U-NET feature recognition, and belongs to the technical field of flow field measurement, and the device comprises a test water tank, a to-be-measured object is installed in the test water tank, the four sides of the test water tank are provided with light-transmitting windows, and optical observation and measurement are carried out; the feature capture high-speed camera is arranged on a window on any side of the test water tank, and the water prism is arranged on a window of an observation surface of the test water tank where the feature capture high-speed camera is located; the active control processing system controls synchronous triggering of the feature capturing high-speed camera and the measuring equipment through the synchronous signal controller and records collected data. According to the invention, the characteristic capturing high-speed camera after algorithm learning is used for accurately positioning and outputting required phase angle information, so that the purpose of testing and measuring a flow field at a certain specific angle is achieved; and an indispensable data basis is provided for verifying and improving related unsteady flow physical models, optimizing hydrodynamic performance of fluid machinery and inhibiting flow instability.

The application discloses a kind of aluminium profile production line's management and control system, specifically relates to metal material processing monitoring technical field, first real-time acquisition crystallizer cooling water and the multiple parameters of aluminium liquid, then according to these parameters constructs the three-dimensional flow pattern of cooling water in crystallizer. Then by calculating the mixed index and cold layer volume fraction in the atlas to determine whether the flow instability precursor appears.Once it is determined to be unstable, the required unfolding degree is calculated according to the aluminium liquid temperature and the falling height, and finally the intelligent spoiler array is executed to adjust to form controllable micro-turbulence in the cooling water channel; the application realizes early warning of instability precursor by sensing the micro-flow of cooling water, constructing three-dimensional atlas and calculating the mixed index and cold layer volume fraction; after determining instability, the intelligent spoiler array is dynamically adjusted according to the aluminium liquid temperature and the falling height to form controllable micro-turbulence to actively destroy the explosion trigger condition, and the intrinsic safety and intelligent active control level of aluminium profile production line are improved.

This invention discloses an experimental apparatus and method for investigating the flow instability of the first wall of a fusion reactor's water-cooled blanket. The experimental apparatus includes: an experimental section, an inlet manifold, an outlet manifold, and a connecting pipe assembly; the connecting pipe assembly includes multiple connecting pipes; the experimental section includes a main body, with a first channel and a second channel internally; the inlet manifold includes an inlet manifold body and at least two inlet manifold connectors, which are respectively connected to the first and second channels; the outlet manifold includes an outlet manifold body and at least two outlet manifold connectors, which are respectively connected to the first and second channels; the experimental section body, the inlet manifold, and the outlet manifold are connected by the connecting pipe assembly to form two flow paths. The use of a two-channel slice model preserves the structural characteristics of the first wall of the fusion reactor's water-cooled blanket to the greatest extent, effectively reflecting the flow instability characteristics of the first wall and reducing experimental costs.

The present invention discloses a method for monitoring and early warning of power instability based on deep learning, comprising: identifying power reverse flow events and potential reverse flow instability events based on power flow data of the power system; constructing a power instability pattern recognition model to identify the instability pattern and instability event risk level of potential reverse flow instability events; identifying key nodes of the power grid with excessive reverse flow impact load based on the reverse flow impact factor of the node; determining the amount of load that needs to be transferred based on the load deviation value of the key nodes of the power grid with excessive reverse flow impact load, and formulating a load control plan; predicting the time point when the instability precursor event turns into a reverse flow instability event based on the power instability pattern recognition model; evaluating the stability of the power grid system after implementing the load control plan, and optimizing the control parameters based on the control feedback data. The present invention significantly improves the power system's monitoring, early warning and dynamic control capabilities for reverse flow and instability events, effectively ensuring the safe and stable operation of the power grid.

The invention discloses a rod bundle channel flow instability early warning method based on disturbance wave modal identification, and relates to the technical field of nuclear reactor thermal hydraulic safety. The method comprises the steps of collecting a multi-source signal of a two-phase flow in a target rod bundle channel, and performing preprocessing to obtain multi-channel time sequence data; reconstructing space-time evolution information of the disturbance wave field and the two-phase flow characteristic parameters based on the multi-channel time sequence data; modal decomposition is carried out on the spatio-temporal evolution information, and modal characteristic parameters after decomposition are calculated; based on a preset early warning criterion, the modal characteristic parameters obtained through real-time calculation are evaluated; the early warning criterion is associated with a mapping relation between different flow instability types and specific disturbance wave modal characteristic parameters; and according to an evaluation result, executing graded early warning and outputting related information. According to the method, the flow instability early warning and type distinguishing in the accident can be realized by identifying and analyzing the modal characteristics of the specific disturbance waves in the flow channel in real time.

The invention relates to the technical field of aircraft engine design, and particularly provides a method for acquiring an over-stall steady-state flow field of a gas compressor. The gas compressor comprises a rotor and a stator, and the stator is arranged at the downstream of the rotor; the compressor further comprises an auxiliary body, the auxiliary body is arranged on the downstream portion of the stator, the auxiliary body is in a disc shape, and the auxiliary body generates an auxiliary force field to provide aerodynamic damping at a low flow point. The auxiliary body is introduced to the downstream of the air compressor, so that the aerodynamic damping of the compression system can be improved, and the flow instability phenomenon is inhibited.

A method can include detecting instability of multiphase fluid flow in a multiphase fluid production system using sensor measurements from the multiphase fluid production system; and, responsive to the detection of instability, increasing gas injection into the multiphase fluid production system until a variation metric of the sensor measurements decreases to a level indicative of stable multiphase fluid flow in the multiphase fluid production system.

This invention relates to the field of fluid mechanics, disclosing a method, apparatus, device, and storage medium for determining instability in rarefied gas flows. By constructing a physical control model based on gas kinetic theory and solving the baseline flow field, modal and nonmodal analyses are performed on the disturbance evolution model. On one hand, eigenvalues ​​of the disturbance growth rate are obtained to determine the absolute instability risk. On the other hand, singular value decomposition is used to obtain the maximum energy growth factor of the initial disturbance within a finite time to quantify the transient energy growth effect caused by the nonorthogonality of linear operators. Finally, the flow instability risk is output based on the combined determination result of the eigenvalues ​​and the maximum energy growth factor. This invention solves the technical problem that existing kinetic modal analysis methods cannot identify subcritical instability due to neglecting the nonorthogonality of linear operators, achieving comprehensive identification of both absolute and subcritical instability, and significantly improving the accuracy and reliability of rarefied gas flow instability prediction.

The invention relates to the technical field of mold design and manufacturing, and discloses a mold flow behavior virtual simulation design system integrating multi-field characteristics, which comprises a multi-modal data acquisition module, a multi-field coupling simulation module, a material gene spectrum library, an intelligent optimization engine module and a physical verification closed loop module, by arranging a multi-modal data acquisition module, a multi-field coupling simulation module, an intelligent optimization engine module and a physical verification closed loop module, interaction between a temperature field and a stress field of a mold can be dynamically simulated through a thermal-force coupling equation, so that error accumulation of traditional separated simulation is avoided; the coupling effect of melt flow and mold deformation is predicted through a fluid-solid coupling equation to solve the problem of flow instability in traditional single-field simulation, and millimeter-scale and micron-scale cross-scale correlation is achieved by coupling a thermal field and a flow field and coupling a force field and a thermal field. Error accumulation of traditional separated simulation is avoided through a thermal-mechanical coupling equation and a fluid-solid coupling equation.

The invention relates to the field of industrial injection molding control, and particularly discloses an in-mold glue injection speed self-adaptive adjustment method and system based on pressure fluctuation feedback, and the method comprises the steps: predicting dissipation structure evolution and flow instability risks through a meta-learner based on cross-batch historical data, actively adjusting the geometric configuration of a micro-texture, and adjusting the flow instability risk of the micro-texture; the inversion dissipation-structure coupling state tensor is fused in real time; abstracting a mold cavity into a weighted fluid network, constructing a seepage model to identify a bottleneck edge and a redundant edge, and generating a speed pulse topology modulation sequence; a dissipation-structure coupling state tensor is used as feedback, rolling optimization speed pulse is controlled based on model prediction, and the glue injection speed is controlled in real time; calculating the prediction deviation degree and the efficiency difference to drive cross-cycle evolution of the element learner; the system comprises four modules corresponding to functions. According to the method, evolution from single-cycle optimization to cross-cycle element learning is achieved through cooperation of micro-texture active regulation and control and speed self-adaptive adjustment, flow instability is effectively inhibited, and the product quality consistency is improved.

The invention discloses a method for diagnosing hydraulic instability of hydraulic machinery based on joint symbolic dynamics entropy. The method comprises the following steps: firstly, collecting a vibration signal through a vibration sensor mounted outside a system; the collected vibration signals are preprocessed, and characteristic parameters representing internal flow of the system are extracted; then establishing and training a hydraulic instability diagnosis model; and finally, collecting vibration signals on line in real time, calculating the fine composite multi-scale joint symbol dynamics entropy of unknown signals, constructing feature vectors, and inputting the feature vectors into the trained hydraulic instability diagnosis model to diagnose the internal flow state of the unit. According to the method, the problem of noise interference in traditional time domain and frequency domain analysis in the prior art is solved, the accuracy of flow instability diagnosis is improved, and meanwhile the method can be further expanded in practical engineering with the low signal-to-noise ratio.

The application discloses a vortex generator control method, related devices and a centrifugal compressor, and relates to the field of compressors. According to the current flow of the diffuser, a target inclination angle between a target vortex generator arranged at a stall-inducing position of the diffuser and an inner wall surface of a casing is determined from a preset flow angle model. The target vortex generator is arranged at a target position of the inner wall surface of the casing, and the structural parameters and the installation angle of the target vortex generator are obtained based on a structural optimization model. According to a real-time inclination angle deviation, an electromagnetic torque acting on the target vortex generator is adjusted, and an electromagnet arranged on an outer wall surface of the casing is controlled based on a control current corresponding to the adjusted electromagnetic torque. Through detection of the flow of the diffuser, the inclination angle of the vortex generator arranged on the inner wall surface is adaptively adjusted, and then flow field regulation at the stall-inducing position of the diffuser is realized, so that the flow instability problem of the compressor is effectively solved.