9 results about "Compressible flow" patented technology

This invention belongs to the field of thermal turbine technology and discloses an entropy efficiency test and CFD optimization method for a centripetal steam turbine. First, a centripetal steam turbine prototype is run under set operating conditions, and multiple operating parameters are collected simultaneously. Valid samples are selected using steady-state criteria to construct an experimental baseline. Then, a complete three-dimensional fluid computational domain is established, and the compressible flow control equations are solved, coupled with… SST k-omega The turbulence model and actual water vapor properties are used to solve for flow heat transfer, and the total pressure loss is decoupled into components. Finally, flow field parameters are extracted to analyze the loss mechanism. The model is calibrated through closed-loop iterative comparison of CFD and experimental results under each operating condition to achieve targeted structural optimization. This invention focuses on suppressing four types of dominant losses, maintaining the isentropic efficiency at 0.72–0.82 and the total pressure loss at 2.0%–2.5% within the flow rate range of 0.45–0.65 kg / s. The normalized RMSE consistency index between simulation and experiment reaches over 0.97, which can improve the reliability of performance prediction under wide operating conditions and shorten the iteration time.

The invention relates to the technical field of wind power generation, and discloses a wind driven generator generating capacity calculation method and device based on compressible flow, and the method comprises the steps: obtaining a free incoming flow parameter of a wind power plant corresponding to a target wind driven generator, and determining a stagnation state parameter of the upstream of a fan based on the free incoming flow parameter; key state parameters of a fan downstream wake flow area are obtained, and density parameters of an incoming flow area and density parameters of a wake flow area are determined based on the free incoming flow parameters and the key state parameters of the fan downstream wake flow area; constructing a compressible flow physical model based on the free incoming flow parameter, the stagnation state parameter of the upstream of the fan, the key state parameter of the wake flow area of the downstream of the fan, the density parameter of the incoming flow area and the density parameter of the wake flow area; and solving the compressible flow physical model, and determining the generating capacity of the wind driven generator. According to the method, the performance prediction precision of the large-scale wind driven generator under the complex working condition is remarkably improved.

The application discloses a method for simulating transient heat and mass transfer process of an aircraft surface based on partition modeling and interface coupling, separates and solves high-speed compressible flow of an outer flow area of the aircraft and low-speed flow of an inner flow area of the aircraft based on the idea of 'partition modeling and interface coupling', and designs a transmission method between data of the inner flow area and the outer flow area, so that transient coupling solution of the inner flow field and the outer flow field of the aircraft is realized. The application comprehensively considers the flow of the coolant in the multi-hole shell of the aircraft under the operating condition and the non-steady heat and mass transfer process between the coolant and the high-Mach-number flow field outside the multi-hole shell, can accurately predict temperature and heat flow distribution of the surface structure of the aircraft under the operating condition, and has guiding significance for fine design of the surface thermal structure and the cooling system of the aircraft.

The present application relates to the technical field of blade simulation design, in particular to a steam turbine wide load blade aerodynamic-structure coupling simulation design method, comprising: based on the initial geometric configuration of the blade, a three-dimensional unsteady steam compressible flow model of the blade channel is established in the fluid solver to simulate the strong unsteady steam excitation in the wide load range; a blade-disk finite element model is built in the structural dynamics solver, and the blade root contact nonlinearity and material nonlinearity conditions are included; a two-way real-time data exchange interface of the two types of solvers is constructed, the time-varying aerodynamic load of the blade wet surface is extracted and mapped as the structural model node force boundary condition; the blade transient dynamic response and dynamic displacement field are solved, and through coupling iterative operation, the blade aerodynamic-structure integrated coupling simulation calculation under wide load working condition is completed, and the interaction relationship between the variable working condition airflow excitation and the structural dynamic deformation is truly reflected.

The invention belongs to the technical field of solving of an incompressible flow problem in an irregular region, and particularly discloses a high-order explicit compact difference method for the incompressible flow problem in the irregular region, which comprises the following steps: constructing a rectangular region containing the irregular region, and carrying out grid division on the rectangular region; arranging a Lagrange point on the boundary of the irregular region; explicit processing of incompressible flow is achieved by solving an entropy damping artificial compressibility equation; realizing high-precision discrete solution of the equation by using a high-order compact difference format to obtain flow field information of a rectangular region; interpolation transfer between the boundary of the irregular region and the flow field is realized by combining an immersion boundary method, coupling of fluid acting force is completed, and then flow field information in the irregular region is extracted. According to the method, explicit solution of the incompressible flow problem is solved by fusing the entropy damping artificial compressibility equation, high-precision solution is realized by using a compact difference format, and use of the compact difference method in an irregular region is realized by combining an immersed boundary method.

This invention discloses a method and system for performance analysis and optimization of heat pipes with multi-working-fluid and multi-wick structures, belonging to the field of heat pipe thermal management technology. The method uses the CGS unit system to complete parameter standardization and initialization, calculates the thermophysical parameters of the multi-working-fluid and the hydraulic characteristics of the multi-wick, couples five types of pressure drops and incorporates the compressible flow effect of the adiabatic section, constructs a sound velocity and carry-over limit model, and completes directional optimization through multi-strategy iteration to output performance curves. The system includes parameter, property, hydraulic, coupling, calculation, optimization, and output modules. This invention covers the entire temperature range of -50 to 1200℃, is compatible with five types of wicks, has high calculation accuracy, can predict failure, is highly efficient in iteration, and is practical for engineering applications. It is suitable for the design, verification, and optimization of heat pipes in spacecraft thermal control, high-end electronic heat dissipation, and nuclear energy device thermal management.

This invention provides a numerical solution method for weakly compressible aeroacoustics based on Roe Riemannian calculations, comprising the following steps: establishing a sound field computational domain; obtaining the ground-state flow field of the weakly compressible flow; mapping the ground-state flow field to the sound field computational domain; interpolating the center values ​​of the cells in the sound field computational domain to the interface between the cell and adjacent cells; calculating the mean value at the interface using Roe averaging; calculating the flux at the interface; and solving the acoustic control equations established using linearized Euler equations. This invention can be widely applied in the field of aerodynamic noise calculation technology.

The application provides an airfoil flow field prediction method and system based on a spectral domain residual perception neural network, and belongs to the technical field of aircraft design; the method comprises the following steps: constructing an airfoil geometry database containing coordinate information of multiple standard airfoils; constructing an airfoil flow field database; based on a finite volume method Fluent solver, simulating a steady compressible flow field under a high Reynolds number condition to generate airfoil flow field data; extracting airfoil geometry features by using a self-encoder model with a residual connection mechanism; constructing a spectral domain residual perception neural network and introducing a Fourier transform and a conditional position coding mechanism; and predicting the airfoil flow field by using the trained spectral domain residual perception neural network. Through a segmented modeling framework, the application decouples the geometry feature extraction and flow field prediction processes, can realize efficient modeling under different types of grids and data distributions, and realizes accurate prediction of the airfoil flow field.

The invention provides an airfoil flow field prediction method and system based on a spectral domain residual error perception neural network, and belongs to the technical field of aircraft design. Comprising the following steps: constructing an airfoil profile geometric database containing multiple pieces of standard airfoil profile coordinate information; constructing an airfoil flow field database, carrying out steady compressible flow field simulation under the condition of high Reynolds number based on a Fluent solver of a finite volume method, and generating airfoil flow field data; an autoencoder model with a residual connection mechanism is adopted to extract geometric features of the airfoil; constructing a spectral domain residual error perception neural network, and introducing Fourier transform and a conditional position coding mechanism; and utilizing the trained spectral domain residual error perception neural network to carry out airfoil flow field prediction. According to the method, geometric feature extraction and the flow field prediction process are decoupled through a sectional modeling framework, efficient modeling can be achieved under different types of grid and data distribution, and accurate prediction of the airfoil flow field is achieved.