Steady Temperature Field Research Articles

The Research of Space Temperature Distribution in Solid Tower of Extradosed Cable-stayed Bridge

Based on space temperature field test in solid tower of extradosed cable-stayed bridge, the method to calculate the space temperature field in solid concrete bridge tower is put forward systematically. By defining a series of meteorological parameters and concrete thermal parameters, the bridge tower temperature distribution is gotten. Compared with the experimental data, error is found within 21.38%, which shows that the temperature field algorithm is reasonable. Under the steady temperature field state, bridge tower section temperature distribution is analyzed within 24 hours, the result shows: maximum negative temperature difference appears on sunrise. Maximum negative temperature difference in transverse and longitudinal direction of bridge is 5.1 °C and 4.2 °C respectively. The most-positive temperature difference in transverse direction appears at 15 PM. The temperature difference value is about 20°C. This research simulates the temperature distribution in transverse and longitudinal directions of the bridge when maximum negative temperature difference appears in solid concrete bridge towers and provides the curve equation.

The Research of Space Temperature Distribution in Solid Tower of Extradosed Cable-stayed Bridge

Based on space temperature field test in solid tower of extradosed cable-stayed bridge, the method to calculate the space temperature field in concrete solid bridge tower is put forward systematically. By entering a series of meteoro- logical parameters and concrete thermal parameters, the bridge tower temperature distribution is gotten. Compared with experimental data, error is within 21.38%, which shows that temperature field algorithm is reasonable. Under the steady temperature field state, analyzing bridge tower section temperature distribution within 24 hours, the result shows: maxi- mum negative temperature difference appears in the moment of sunrise. Maximum negative temperature difference in transverse and longitudinal direction of bridge respectively is 5.1 °C and 4.2 °C. The most-positive temperature difference in transverse direction appears at 15 PM. The temperature difference value is about 20°C. This research simulates the temperature distribution in transverse and longitudinal direction of bridge when maximum negative temperature differ- ence appears in solid concrete bridge towers and provides the curve equation.

Effect of carbon nanotubes on the thermoelectric properties of CFRP laminate for aircraft applications

The present paper focuses on the thermoelectric behavior of carbon nanotube-charged carbon fiber-reinforced polymer composite materials for aircraft applications. Two types of samples: Type A with carbon nanotube and Type B without carbon nanotube), and with two different stacking sequences (unidirectional—[0]8, cross orthogonal—[0/90]4) were manufactured for the thermoelectric experiments, DC electrical current was injected through the specimens, and the temperature of the specimens was monitored simultaneously in order to deduce the effect of carbon nanotube on the electrical conductivity change of the specimen. During the test, transient and steady temperature fields were measured on the sample surfaces by infrared thermography, and real-time voltage measurements monitor the sample electrical resistance. The results show that the presence of carbon nanotube produces increasing values of longitudinal electric conductivity σ L of about 10%. At 9 A, the maximum temperature value is around 95℃ for unidirectional and 145℃ for cross orthogonal samples. The presence of carbon nanotube tends to decrease the entire range of maximum temperatures, about 7% on average for the unidirectional and about 4% on average for cross orthogonal samples.

ANALYTICAL EXPRESSIONS FOR EXOTHERMIC EXPLOSIONS IN A SLAB

Analytical solutions for the strongly exothermic decomposition of combustible material are discussed in this paper. Combustible material uniformly distributed between symmetrically heated parallel plates under Sensitized, Arrhenius and Bimolecular reaction rates are also discussed neglecting consumption of material. Approximate analytical expressions of steady state temperature fields are derived by using Homotopy analysis method (HPM) for various values of relevant dimensionless parameters. Analytical results are compounded with perturbation technique and numerical simulation. Analytical results are coinciding with numerical simulation and agreement is noted. The present method simple, less computational and applicable for solving strongly non-linear initial and boundary value problems.

Thermal Analysis of Water-Cooled Permanent Magnet Synchronous Motor for Electric Vehicles

In order to study heat generation and dissipation of water-cooled permanent magnet synchronous motor in electric vehicle, the major energy loss was calculated and the finite element model for interior heat transfer simulation was established based on appropriate simplification and equivalent processing. The fluid-solid-thermal coupling simulation was accomplished by CFD method and the steady state temperature field of the motor under rated condition was obtained. The simulation is verified by experiment and gives an effective support in motor’s cooling system design.

3D loss and heat analysis at the end region of 4-poles 1150 MW nuclear power turbine generator

Abstract To study the principle of loss and heat at the end region of large 4-poles nuclear power turbine generator, 3D transient electromagnetic field and 3D steady temperature field finite element (FE) models of the end region are established respectively. Considering the factors such as rotor motion, core non-linearity and time-varying of electromagnetic field, the anisotropic heat conductivity and different heat dissipation conditions of stator end region, a 50 Hz, 1150 MW, 4-poles nuclear power turbine generator is investigated. The loss and heat at the generator end region are calculated respectively at no-load and rated-load, and the calculation results are compared with the test data. The result shows that the calculation model is accurate and the generator design is suitable. The method is valuable for the research of loss and heat at the end region of large 4-poles nuclear power turbine generator and the improvement of the generator’s operation stability. The method has been applied successfully for the design of the larger nuclear power turbine generators

The Numerical Analysis of Spiral Heat Exchanger

The lumped parameter method was used to establish a mathematical model for the spiral heat exchanger with complex structures and specific heat transfer. By implementing the finite difference method, the differential equation was discretized, and then the steady temperature field of the spiral heat exchanger and the dynamic response of temperature can be obtained under boundary conditions and initial conditions. And the essential correctness and measurement accuracy of the model was proved by fluent. The results show that this model can simulate the temperature field and the dynamic response of it well.

Analytical solution to steady-state temperature field of two freezing pipes with different temperatures

The existing analytical formulas to calculate the temperature field distribution of artificial frozen soil walls are all based on the conditions that the surface temperatures of all freezing pipes are equivalent. In this paper, analytical solution of steady state temperature field of two freezing pipes with different temperatures is deduced based on thermal potential superposition method. The correctness of the analytical formulas is verified by comparing the temperature field distributions of the analytical formulas and those of the numerical simulations in the same conditions. And discussions are made to analyze the influence of some parameters on temperature field distribution of this condition.

The Research on Creep Deformation and Thermal Stress of Cast Copper Staves

The creep deformation of the cast copper cooling staves was researched based on the steady temperature field by using thermal - mechanical coupling finite element transient analysis method and ABAQUS software. The results show that the creep deformation only under the effect of thermal stress is slight and negligible compared to the deformation generated by thermal expansion. The total tress is not adequate to crack the stave body. Therefore, the cast copper stave can meet the requirements of blast furnace longevity.

Finite Elements Prediction of Temperature Field and Thermal Stresses in Thermal Roll of Calendering Process

A simplified numerical approach based on the Finite Element Method (FEM) to compute the steady state temperature field and thermal stresses in a thermal roll of a calender machine is proposed. The temperature distributions of the working roll and thermal oil were investigated by fluid dynamics theory. With the acquired roll body temperature, the deformation and stress were calculated. This approach is suitable for fluid-structural and thermal stress problems and hence helpful for the design and improvement of such equipment.

Finite Element Analysis on Thermal Characteristic of a High Precision Turning Center’s Headstock

Theperformances of the turning center will be influenced by its thermalcharacteristics seriously, and accurately predict thermal characteristic of themachine tool is helpful to improve the design level. The headstock of a high precision turning center has been regarded as the researchobjects, and its thermal properties and influence on the performance of the turningcenter are studied. First based the finite element analysis model that has beenconstructed, the steady temperature field distribution and thermal equilibriumtime of the headstock are calculated, and then the temperature field andthermal deformation have been calculated also, and analysis to identify thetrend of the headstock heat distortion are also been done. Some of the keyfactors on the thermal performance of turning center are also studied. Thestudy lays a foundation for the thermal error compensation of the headstock.

Effect of Michell Function on Steady State Behavior of Thick Circular Plate with Internal Heat Generation

The present paper deals with the determination of displacement and thermal stresses in a thick M ≠ 0 circular plate under steady temperature field. Arbitrary heat flux is applied at the upper surface of a thick M ≠ 0 circular plate, whereas lower surface at zero temperature and the fixed circular edge is thermally insulated. Here we compute the effects of Michell function on the thickness of circular plate with internal heat generation. The governing heat conduction equation has been solved by the method of integral transform technique. The results are obtained in a series form in terms of Bessel’s functions. The results for temperature change, displacement and stresses have been computed numerically and illustrated graphically.

基于ANSYS的家电用永磁同步电动机温度场分析

本文根据传热学理论利用ANSYS软件建立了永磁同步电机稳态运行条件下温度场的计算模型，并以某家电用1 kw空气自冷永磁同步电动机为例应用有限元法计算了电磁损耗及稳态温度场分布情况。对电机进行负载稳态温升实验，仿真结果和实验结果基本一致，说明本文在电机热场分析中采取的方法对于电机设计和热分析具有一定的工程应用价值，同时证明所设计的电机安全合理。 Utilizing ASNSY software, we can build models of permanent magnet motor in steady state operation according to the theory of heat transfer. With household 1 kw air-cooled permanent magnet synchronous motor as an example, through finite element method to calculate the steady temperature field and electromagnetic loss of the motor. For the load steady state temperature rise experiment of the motor, the simulation results and experimental results are basically the same, which account for that method adopted for the motor design and analysis in the motor thermal field analysis is of certain valuable for engineering application.

Hot‐wire measurement in turbulent flow behind a parallel‐line heat source

AbstractAn interaction of the free turbulent shear flow and the steady temperature field, which develops to the homogeneity, was studied. The temperature field was generated by parallel thin heated wires. The isotropic grid turbulence is supposed. Heated wire generates large cross temperature gradients and development of the temperature field was investigated experimentally. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Coupled Heat Transfer Analysis of Piston Crown, Piston Rings and Cylinder Liner

MAN Diesel’s 6S50MC-C disel is a two-stroke marine diesel engine. As the boundary conditions of temperature field distribution, the mean temperature and mean heat transfer coefficient are calculated firstly. The coupled heat transfer of piston crown, piston rings and cylinder liner are analyzed. The steady temperature field and the transient heat transfer under starting condition of diesel engine are obtained in ANSYS. Maximum temperature is 413.55°C in the top surface edge of the piston crown. 59.5% of the total heat from high-temperature fuel gas heat is absorbed by the cooling oil. The temperature of piston crown is effectively reduced by shaker cooling. The load of diesel engine should be increased slowly to prevent stress concentration. To reduce the destructive effect, enhancing cooling and warming up the main engine are requested.

The Finite Element Thermal Analysis for Lubricating Oil Transfer Pump in Different Convection Heat Transfer Coefficient with Special Material Properties

Lubricating oil transfer pump is important functional subsystem in two-screw pump system, and all moving parts works very fast, it is easy to generate heat, that not only affect the lubricating oil transfer pump’s temperature field, but also make transmission failure by the thermal deformation which caused by high temperature of parts in contact. This paper established a finite element thermal analysis model and boundary conditions of lubricating oil transfer pump, and calculated the temperature field and thermal deformation for it during the process of oil extraction in different coefficient of convective heat transfer, analysis the change rule of the steady state temperature field and thermal deformation, proved that lubricating oil transfer pump can normal work in certain conditions.

The errors in determining the thermal characteristics of semitransparent materials by a pulse method

The errors in determining the thermal characteristics of a semitransparent material by a pulsed method are determined by comparing the results of a numerical solution of the problem of the steady temperature field of a sample when a collimated laser pulse of finite duration acts on its surface with the true values of the thermal diffusivity, thermal conductivity, and specific heat capacity.

Thermal Characteristic Analysis on the Headstock of a High Precision CNC Machine Tool

The performances of the precision machine tool will be influenced by its thermal characteristics seriously, and accurately predict the thermal characteristic of the key component of the machine tool is helpful to improve the design level. The headstock of a high precision CNC lathes has been regarded as the research objects, and the thermal properties and its influence on the performance of the machine tool are studied. Finite element analysis model of the headstock has been constructed, and the simulation calculations of the steady temperature field distribution and thermal equilibrium time of the headstock are calculated, and then the analysis to identify the thermal deformation trends of the spindle assembly and the heat distortion of the headstock are also been done. Some of the key factors that have significant influence on the thermal characteristic of the high precision machine tools are also studied. The analysis reveals that the performances of the machine tool will be influenced by the hot asymmetric, the study lays a foundation for the optimization design and thermal error compensation of the spindle assembly.

Study on the Steady State Thermal Analysis Method of Accessory Transmission System

The mathematical model of steady state thermal analysis of accessory transmission system is built according to heat transfer theory, the governing equation functional of the steady state temperature field of accessory transmission system is derived on the basis of the variation principle, and the method to calculate the steady state temperature field of accessory transmission system is proposed with the finite element software ANSYS and its secondary switching language APDL. The result shows that the prediction of temperature field fit in with the heat flow law, then the correctness and validity of the proposed thermal analysis method is verified.

Steady symmetrical temperature field in a hollow spherical particle with temperature-dependent thermal conductivity

In this work, an exact analytical solution to the axisymmetric heat conduction equation for hollow spherical objects with temperature-dependent thermal conductivity is presented. The nonlinear differential equation is first transformed into a linear one by means of an integral transform method. Then, the separation of variables method is employed to solve the transformed linear equation. Ultimately, we use the inverse transform to obtain the physical temperature field. Furthermore, two examples are worked out, i.e., the one-dimensional heat conduction in the radial direction and the two-dimensional case with axial symmetry. The solution is presented as an infinite series in terms of Legendre functions. The problem with spherical symmetry is also solved by using perturbation methods up to the third-order approximation, and the results are compared with the exact solution.