Analysis of transient temperature field in coke drums

One of the primary reasons leading to bulging and cracking in a coke drum is the severe temperature gradient due to cyclic temperature variation. Based on the twodimensional heat conduction theory, an analytical solution of the transient temperature field in the coke drum is obtained, which is different from the known FEM results. The length of the coke drum is considered finite. The dynamic boundary conditions caused by fluid uninterrupted rising in oiling and watering stages are simulated with the iteration method. Numerical results show that the present theoretical model can accurately describe basic features of the transient temperature field in the coke drum. Effects of the geometry of the coke drum and the rising velocity of quench water on the axial temperature gradient are also discussed.     

The transient temperature field existing about a cooled stationary electrical contact

A numerical analysis is formulated and used to determine the transient temperature fields associated with Joule heating of a cooled stationary electrical contact. The contact is treated as a hemisphere. The field equations are developed using complex variables and conformal transforms, and the resulting equations are solved using finite differences.Contours of constant temperature are given that show a maximum temperature located very close to the center of the contact patch; this qualitatively agrees with earlier findings of Holm.     

爆炸场瞬态高温测试的实验研究

针对爆炸场瞬态高温测量需求,从辐射测温原理出发,建立红外比色测温系统。通过黑体炉实验标定出Si/Ge双通道比色测温仪的波长、带宽、光电转换系数等工作参数和测温范围,并将比色测温仪高温测温量程扩展至3 500℃。利用大能量电火花放电产生的爆炸场标定了测温仪的响应时间,结果显示测温仪响应时间不超过10μs。确定了标准测温仪和超限测温仪的温度计算公式,并将比色测温仪应用于TNT柱状炸药和云爆剂（FAE）爆炸场温度测试,可以为爆炸反应过程诊断和爆炸温度毁伤效应评估提供依据。     

Nonlinear damped vibrations of simply-supported sandwich plates in a rapidly changing temperature field

The paper studies the effects of a rapidly changed temperature on the free vibrations of simply supported sandwich plates. It has been taken into account that the properties of the facings and of the core of the sandwich plate change with the temperature. The effects of geometrical nonlinearities on the behaviour of the plate have also been included. The damping is considered by modelling the viscoelastic core as a Voigt-Kelvin solid. A Runge-Kutta method is employed to solve the governing equations and obtain the numerical results. It was found that the rapid change of temperature strongly affects the amplitude and frequency of the vibrations.     

The numerical method for analysing the transient temperature field and transient phase transformation of metal materials in heat treating

In this paper,the Kirchhoffs transformation is popularized to the nonlinear heat conduction problem which the heat conductivity can be expressd as a multinomial of temperature firstly,the boundary condition of heat conduction problem is determined by analytics.Secondly,the incubation peroid superposition and the linear combination law is employed to simulate the transient phasses transformation in the process of heat treatment of materials.That the begin time of phase transformation,the type of phase transformation and the amount of phase constitution is determined simply.Finally,the three-dimension Dual Reciprocity Boundary Element Method is usedto analysis the total process of various heat treatment of component,the results of numerical calculation of examples show that the method provided in this paper is effectivce.     

激光辐照下多层圆柱体中三维瞬态温度场的解析解

考虑外表面的气流影响和层间温度与传热的协调关系,建立了激光辐照下,层合圆柱体中的三维瞬态热传导解析模型。利用特征值法和Bessel函数,导出了各层柱体中三维瞬态温度场的封闭解析解。以一维轴对称问题为例计算了柱体中的瞬态温度场,给出了柱体内部温度随时间的变化和柱体表面换热系数对温度场的影响规律。本文的理论解可进一步用于分析层合圆柱体中的三维瞬态热-力效应,并可作为相应问题的数值模拟中数值模型的修正依据。     

非保守力下温度场中FGM圆板的非线性力学行为

研究了温度场中非保守功能梯度材料(FGM)圆板的非线性力学行为.基于经典板理论,推导了受非保守力作用的FGM圆板在温度场中的控制微分方程.采用打靶法分析了由陶瓷二氧化锆和金属钛合金两相材料组成的非保守FGM圆板在均匀和非均匀升温场中的非线性力学行为.给出了不同均匀升温和非均匀升温场下,FGM圆板在非保守载荷作用下的平衡...     

Steady temperature field in a semi-infinite composite plate

Summary This paper presents a contribution to generalizing classical problems on heat conduction to the case of composite media. The calculations are comparatively complicated and lead to new results not given in the literature. General deductions are applied to special cases.     

Axisymmetric non-Fourier temperature field in a hollow sphere

The non-Fourier axisymmetric (2+1)-dimensional temperature field within a hollow sphere is analytically investigated by the solution of the well-known Cattaneo–Vernotte hyperbolic heat conduction equation. The material is assumed to be homogeneous and isotropic with temperature-independent thermal properties. The method of solution is the standard separation of variables method. General linear time-independent boundary conditions are considered. Ultimately, the presented solution is applied to a (1+1)—as well as a (2+1)—dimensional problem, and their respective non-Fourier thermal behavior is studied. The present solution can be reduced to special cases of interest by choosing appropriate boundary conditions parameters. Dedicated to Prof. Gholamali Atefi, with appreciation and admiration on the occasion of his 65th birthday.     

Nonlinear deformation of current-carrying plates in a nonsteady magnetic field

Kiev University. Translated from Prikladnaya Mekhanika, Vol. 26 No. 6, pp. 45–48, June, 1990.     

Nonlinear vibration of a rotating cantilever beam in a surrounding magnetic field

The nonlinear vibrations of a rotating cantilever beam made of magnetoelastic materials surrounded by a uniform magnetic field are investigated. The kinetic energy, potential energy and work done by the electromagnetic force are obtained. A nonlinear dynamic model, based on the Hamilton principle, which includes the stretching vibration and bending vibration is presented. The Galerkin method is adopted to discretize the dynamic equations. The proposed method is validated by comparison with the literature. The nonlinear behaviors of the responses are studied. Then simulations for different kinds of magnetic field are conducted. The effects of magnetic field parameters, including the amplitude, plane angle, spatial angle and time-varying frequency, on the dynamic behaviors of the stretching motion and bending motion are investigated in detail. The results illustrate that the interaction effects between the rotating cantilever beam and the magnetic field will increase the vibration amplitude and fluctuation of the beam. In particular, we found that: collinear magnetic fields with equal amplitude lead to the same dynamic responses; the amplitude of magnetic field intensity increases the dynamic responses remarkably; the response amplitude changes nonlinearly with the plane angle and spatial angle of the magnetic field; and the increase of time-varying frequency enhances dynamic responses of the rotating cantilever beam.     

On the simulation of the transient temperature field or some viscoelasticity problems by structural analysis program

An idea is presented to solve the parabolic differential equation by the hyperbolic differential equation. We can simulate and compute the transient temperature field problems by a structural analysis program. Using only a single structural analysis program, the users can compute both temperature and thermal stress distributions on the same finite element mesh. The method thus extends the application of the structural analysis programs which have been implemented widely. As an example, the transient temperature field problem of a square plate is computed. The result is consistent with the theoretical result. A similar method for simulating some viscoelasticity problems of Kelvin model is also presented.     

Estimate of the temperature field in a compressible medium

Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, No. 1, pp. 23–26, January–February, 1992.     

Magneto-thermo-elastic stresses induced by a transient magnetic field in a conducting solid circular cylinder

In the present paper, dynamic and quasi-static behaviors of magneto-thermo-elastic stresses induced by a transient magnetic field in a conducting solid circular cylinder are investigated. It is assumed that a transient magnetic field which is defined by an arbitrary function of time acts on the surface of the solid cylinder in the direction parallel to its surface. Fundamental equations of plane axisymmetrical electromagnetic, temperature, and elastic fields are formulated. Then, solutions of magnetic field, eddy current, temperature change and both dynamic solutions and quasi-static ones of stresses and deformations are analytically derived in the forms including the arbitrary function. The solutions of stresses are determined to be sums of thermal stress caused by eddy current loss and magnetic stress caused by Lorentz force. For this case that the arbitrary function is given by the smoothed ramp function with sine function, the dynamic and quasi-static behaviors of the stresses are examined by numerical calculations.     

Nonlinear electric field oscillations in continuous media

Strong nonlinear potential and drift-velocity waves in a nonequilibrium medium, in which the current-carrier collision frequency depends on the electric field, are considered in the hydrodynamic approximation.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, Vol. 10, No. 3, pp. 55–57, May–June, 1969.     

Non-fourier temperature field in a solid homogeneous finite hollow cylinder

Analytical solution of the non-Fourier Axisymmetric temperature field within a finite hollow cylinder is investigated considering the Cattaneo-Vernotte constitutive heat flux relation. The solution is found for the most general linear time-independent boundary conditions. The material is assumed to be homogeneous and isotropic with temperature-independent thermal properties. The standard method of separation of variables is used. The present solution can be reduced to special problems of interest by choosing appropriate boundary condition parameters. The solution is applied for two special cases including constant heat flux and the Gaussian distribution heating of a cylinder, and their respective non-Fourier thermal behavior is studied.