6 results about "Heat equation" patented technology

The application provides an unconventional oil and gas reservoir thermal fluid-solid coupling numerical simulation method and system, and the method comprises the following steps: constructing a multiphase numerical model coupling a temperature field, a seepage field and a stress field; the multiphase numerical model integrates a Cahn-Hilliard equation, a heat conduction equation, a continuity equation, a Navier-Stokes equation and a mechanical equilibrium equation; determining a model calculation domain of the multiphase numerical model; performing grid discretization processing on the model calculation domain and performing grid refinement processing on the periphery of a mass flow inlet and a pressure outlet, thereby obtaining a plurality of grid units; inputting environmental parameters and initial condition parameters into the multiphase numerical model, controlling the multiphase numerical model to perform discrete calculation in each grid unit, judging whether a convergence condition is met, if the convergence condition is met, updating physical property parameters of a multiphase fluid according to a current temperature and pressure, and outputting a numerical simulation result of the unconventional oil and gas reservoir. The application can reduce the production capacity prediction deviation.

The application provides a kind of calculation method, system and computer equipment for fluid-structure coupling heat transfer.For the problem that existing weak coupling algorithm long tail iteration converges slowly in later stage, a two-stage decoupling acceleration strategy is proposed.In the first stage, fluid-solid weak coupling algorithm is iterated, and an early truncation mechanism is introduced: when the global temperature rise has not finally converged, but the convective heat transfer coefficient of the interface reaches a stable convergence state first, stop the fluid-structure two-way iteration and extract the current convective heat transfer coefficient;In the second stage, the convective heat transfer coefficient is applied as a thermal boundary condition to the solid calculation domain, and the flow equation operation is stopped, and the heat conduction equation of the solid is solved in a one-way decoupling state until complete steady state.The application skillfully utilizes the space-time difference of the convergence speed of the characteristic physical quantity, eliminates the redundant iteration without losing the engineering precision, and greatly improves the solving efficiency of heat transfer simulation.

The invention provides a multi-physics coupling simulation method and system for reverse pouring of a tunnel arch wall. The method comprises the steps that a two-dimensional computational domain is constructed and discretized; a Herschel-Bulkley model containing a thixotropic recovery mechanism and a first-order differential equation are adopted to describe the shear stress and thixotropic evolution of the concrete; based on an Arrhenius model and a heat conduction equation, establishing a coupling relationship between the temperature, the hydration degree and the rheological parameters; solving a flow field by an explicit projection method; a VOF-PLIC algorithm is adopted to track a concrete-air interface; calculating template side pressure by combining a flow field and stress, and outputting a distribution curve and an extreme value; dynamically controlling the step length according to a CFL criterion and circulating to a set height or terminating; the system comprises a modeling module, a material model module, a thermal-chemical coupling module, a flow field solving module, an interface tracking module, a side pressure evaluation module and a time control module. According to the method, the multi-field coupling effect is integrated, and the accuracy of prediction and evaluation of the whole reverse pouring process is improved.

The application provides a kind of multi-physical field coupling simulation method and system for tunnel arch wall reverse pouring, method includes: constructing two-dimensional calculation domain and discretizing it;Adopt Herschel-Bulkley model containing thixotropy recovery mechanism and first-order differential equation to describe concrete shear stress and thixotropic evolution;Based on Arrhenius model and heat conduction equation, the coupling relationship between temperature, hydration degree and rheological parameter is established;Solve flow field by explicit projection method;Adopt VOF-PLIC algorithm to track concrete-air interface;Combine flow field and stress calculation template side pressure, and output distribution curve and extreme value;According to CFL criterion, dynamically control step length and cycle to set height or terminate;System contains modeling, material model, thermal-hydro coupling, flow field solving, interface tracking, side pressure evaluation and time control module;The application integrates multi-field coupling effect, improves the accuracy of reverse pouring whole process prediction and evaluation.

The present application relates to the technical field of hot crack determination, and particularly relates to a kind of hot crack determination method of internal press-down of casting blank based on thermal coupling model, comprising using two-dimensional Fourier heat equation to calculate the solidification process of casting blank;Using equivalent specific heat capacity method to handle solidification latent heat;Calculate the center solid phase rate of the solidification process of casting blank;Calculate the average heat flux density of crystallizer stage, and the instantaneous heat flux density distributed along the casting direction of crystallizer;Thermal coupling model is constructed.The present application is based on thermal coupling model simulation, and determines whether the press-down process of continuous casting produces press-down hot crack.

This invention discloses a three-dimensional temperature analysis method for substrates containing randomly distributed irregularly distributed heat-generating vias, belonging to the field of microelectronics technology. The method includes: establishing a mathematical and physical model; based on the mathematical and physical model, using a step function to establish expressions for the thermal conductivity, volumetric heat capacity, and heat sources of the vias and chips within the substrate; establishing a three-dimensional heat conduction equation; obtaining eigenvalue equations with unknown coefficients in each dimension based on the three-dimensional heat conduction equation and the thermal model expression containing Fourier coefficients; solving for known eigenvalue equations based on the temperature boundary conditions of the substrate; updating the thermal model expression based on the known eigenvalue equations; and jointly solving for the thermal conductivity, volumetric heat capacity, heat source expression within the substrate, and the three-dimensional heat conduction equation to obtain the Fourier coefficients under the known eigenvalue equation combination corresponding to the eigenvalues ​​in each dimension, and substituting these coefficients into the updated thermal model expression to obtain the temperature distribution of the substrate.