Patent classifications
G06F2119/08
THERMAL STRUCTURE COUPLING ANAYSIS METHOD OF A SOLID ROCKET MOTOR NOZZLE CONSIDERING THE STRCTURAL GAPS
The invention provides a thermal structure coupling analysis method of a solid rocket motor nozzle considering the structural gaps, comprising S1: establish a model of flow field in nozzle and ascertain the cross-sectional area at different positions along the axis, perform quasi-one-dimensional isentropic flow analysis of the nozzle flow field by Newton iteration method; S2: use Bartz formula to ascertain the boundary of the nozzle convective heat transfer coefficient; S3: establish a numerical analysis project of nozzle thermal structure; a two-dimensional axisymmetric model of the nozzle thermal protection structure and a material model thereof; S4: proceed a numerical analysis of the nozzle thermal protection structure heat transfer, including model setting, material setting, contact setting, meshing, solution parameter setting, boundary condition setting, solution and result post-processing; S5: proceed a numerical analysis of the nozzle thermal protection structure thermal stress, including solution parameter setting, boundary condition setting, solution and result post-processing.
System and method for performing a thermal simulation of a powder bed based additive process
A method for performing a thermal simulation of an additive manufacturing process that includes accessing a voxel model representing a representative system using one or more processors. The voxel model includes a first transition associated with a first group of one or more voxels transitioning between liquid and vapor, a second transition associated with a second group of one or more voxels transitioning between solid and liquid, a third transition associated with a third group of one or more voxels undergoing sinter, and a fourth transition associated with a fourth group of one or more voxels undergoing a solid state phase change. The method determines a flux imbalance metric based on a flux, a rate of change of the first transition, a rate of change of the second transition, a rate of change of the third transition, and a rate of change of the fourth transition. The method determines one or more temperatures for the representative system based on the flux imbalance metric.
System and method for designing heating, ventilating, and air-conditioning (HVAC) systems
A simulation system for designing a heating ventilation and air conditioning (HVAC) system is provided. The system comprises an input interface configured to accept thermal data indicative of a target distribution of thermal state and environmental data, and a memory configured to store a building envelope model (BEM), an airflow dynamics model (ADM), and an HVAC model. The simulation system further comprises a processor configured to process the environmental data with the BEM to estimate thermal state of the air at the walls of the environment, and determine one or more design variables, by minimizing a multi-objective cost function. The simulation system further comprises an output interface configured to output the one or more design variables.
Method for calculating temperature-dependent mid-span vertical displacement of girder bridge
A method for calculating a temperature-dependent mid-span vertical displacement of a girder bridge includes: setting a joint rotation of a main girder at each support as an unknown quantity, and establishing an equation according to a bending moment equilibrium condition at the joint; then introducing a sequence to establish a quantitative relationship between each unknown quantity; substituting the relationship into the equation, to obtain an analytical formula for a rotation at each joint; establishing an analytical formula for a bending moment at each joint through a principle of superposition; and finally, establishing an analytical formula for a mid-span vertical displacement of each span girder through a principle of virtual work. This method provides an analytical formula with exact solutions for prismatic girder bridges which have equal side spans yet have any number of spans.
Internal thermal fault diagnosis method of oil-immersed transformer based on deep convolutional neural network and image segmentation
The disclosure provides an internal thermal fault diagnosing method for an oil-immersed transformer based on DCNN and image segmentation, including: 1) dividing an internal area of a transformer, and using fault areas and normal status as labels of DCNN; 2) through lattice Boltzmann simulation, randomly obtaining multiple feature images of the internal temperature field distribution of the transformer under normal and various fault state modes, and the fault area serves as a label to form the underlying training sample set; 3) obtaining historical monitoring information of the infrared camera or temperature sensor, and forming its corresponding fault diagnosis results into labels; 4) combining all monitoring information contained in each sample into one image, and then extracting the same monitoring information from the samples in the sample set to form a new image; 5) segmenting image sample and then inputting the same into DCNN for training to obtain diagnosis results.
Multilayer fluid analysis program, and multilayer fluid analysis system
A computer-readable non-transitory storage medium stores a multilayer fluid analysis program for analyzing a multilayer fluid as 2.5 dimensions in which each layer is divided into elements and each of the elements has information about a layer thickness in a finite element model for the multilayer fluid. The multilayer fluid analysis program allowing a computer to function as: a layer thickness calculation process for calculating the layer thickness of the elements from a simultaneous equation indicating a relationship between stress in a normal direction and a fluid viscosity in the elements without considering a fluid flow in a thickness direction of the layer thickness under a condition that stresses in the normal direction and a tangential direction are balanced at an interface of respective layers and a flow velocity at the interface is continuous; and a display process for displaying a calculation result.
Method and system for online correction of junction temperatures of IGBT in photovoltaic inverter considering aging process
The invention discloses a method and a system for correction of the junction temperatures of an IGBT module in a photovoltaic inverter. The method includes: constructing an electrothermal coupling model of an IGBT model based on a photovoltaic inverter topology, a light radiation intensity, and an ambient temperature; selecting an IGBT collector-emitter on-state voltage drop as an aging parameter and designing an on-state voltage drop sampling circuit to ensure measurement accuracy; constructing an aging database for IGBT modules in different aging stages based on large current and small current injection methods; comparing a junction temperature value output by the electrothermal coupling model with the calibrated junction temperature value and calibrating an aging process coefficient of an electrothermal coupling model correction formula; comparing an IGBT aging monitoring value with the aging threshold to determine the aging process and selecting a corresponding aging process coefficient to ensure accuracy of junction temperature data.
Method for calculating service life of material under action of thermal shock load
The present disclosure discloses a method for calculating the service life of a material under the action of a thermal shock load. The method includes steps of obtaining test results at different thermal shock temperatures and a thermal shock cycle number according to a thermal shock test, and calculating a temperature rise rate to temperature drop rate ratio R.sub.v; calculating a corresponding stress intensity factor ΔK according to a crack length a measured in the test; calculating a thermal stress σ at the notch and a notch stress concentration coefficient k.sub.t of the test specimen; calculating a stress intensity factor threshold ΔK.sub.th according to the crack length a measured in the test; and substituting the obtained the stress intensity factor ΔK, stress intensity factor threshold ΔK.sub.th and temperature rise rate to temperature drop rate ratio R.sub.v into a thermal fatigue crack growth model.
NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM, DATA PROCESSING METHOD, AND DATA PROCESSING APPARATUS
A non-transitory computer-readable storage medium storing a program that causes a processor to execute a process, the process includes reading a plurality of first solutions of an optimization problem represented by a combination of values of a plurality of state variables, converting the plurality of first solutions into a plurality of second solutions by executing principal component analysis on the plurality of first solutions, determining a region that indicates a spread of the plurality of second solutions in a solution space, generating a third solution located at a second position outside the region and away from a first position within the region by a first distance, converting the third solution into a fourth solution that consists of the plurality of state variables, and searching for a solution of the optimization problem by using the fourth solution as an initial value of the plurality of state variables.
LEARNING-BASED POWER MODELING OF A PROCESSOR CORE AND SYSTEMS WITH MULTIPLE PROCESSOR CORES
Learning-based power modeling of a processor core includes generating, using computer hardware, pipeline snapshot data specifying a plurality of snapshots for a pipeline of a processor core. Each snapshot specifies a state of the pipeline for a clock cycle in executing a computer program over a plurality of clock cycles. A plurality of estimates of power consumption for the processor core in executing the computer program for the plurality of clock cycles are determined, using an instruction-based power model executed by the computer hardware, a based on the pipeline snapshot data. The plurality of estimates of power consumption are calculated using the instruction-based power model based on the plurality of snapshots over the plurality of clock cycles.