scholarly journals Thermal condition of cohesion in a two-layer roll of a rolling mill

2019 ◽  
pp. 45-48
Author(s):  
Olga Panteleivna Demyanchenko ◽  
Viktor Lyashenko
Keyword(s):  
Heat Exchange ◽  
Temperature Distribution ◽  
Heat Conductivity ◽  
Rolling Mill ◽  
Thermal Condition ◽  
Thermal Contact ◽  
Homogeneous Equation ◽  
Target Setting ◽  
Radial Section ◽  
Ideal Thermal Contact

A condition of heat exchange between the layershaving different thermalphysic properties in a two-layercylindrical roll of a rolling mill is analyzed foe an ideal thermalcontact. It can be realized with application of the condition ofheat balance of one of the layers in the cylindrical area for ahomogeneous equation of heat conductivity. Analyzed was asimplified target setting in the radial section with a supposition,regarding an averaged in radius temperature distribution in theouter layer. By applying the condition of the thermal balance andby integrating the homogeneous equation of heat conductivity inthe two-layer area a condition of cohesion of an impedance typein case of an ideal thermal contact between the layers wasconstructed.

Stochastic Analysis of Temperature Distribution in a Solid With Random Heat Conductivity

1988 ◽  
Vol 110 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Da Yu Tzou
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Heat Conductivity ◽  
Stochastic Analysis ◽  
Solid Medium ◽  
Mean Value ◽  
Random Response ◽  
Thermal Failure ◽  
Numerical Examples ◽  
The Mean

Stochastic temperature distribution in a solid medium with random heat conductivity is investigated by the method of perturbation. The intrinsic randomness of the thermal conductivity k(x) is considered to be a distribution function with random amplitude in the solid, and several typical stochastic processes are considered in the numerical examples. The formulation used in the present analysis describes a situation that the statistical orders of the random response of the system are the same as those of the intrinsic random excitations, which is characteristic for the problem with extrinsic randomness. The maximum standard deviation of the temperature distribution from the mean value in the solid medium reveals the amount of unexpected energy experienced by the solid continuum, which should be carefully inspected in the thermal-failure design of structures with intrinsic randomness.

scholarly journals Study on non-stationary heat exchange in combined packages of water-resistant protective clothing of firefighters

2020 ◽  
Vol 64 (4) ◽  
pp. 467-476
Author(s):  
A. I. Ol’shanskii ◽  
R. V. Okunev ◽  
A. M. Gusarov
Keyword(s):  
Thermal Conductivity ◽  
Heat Exchange ◽  
Protective Clothing ◽  
Thermal Contact ◽  
Exchange Process ◽  
Toxic Substances ◽  
Nonlinear Transport ◽  
Stationary Heat ◽  
Technical Requirements ◽  
Linearization Methods

The results of research of non-stationary heat exchange in combined packages intended for creation of special water- and heat-resistant protective clothing of firefighters from dangerous and harmful factors during emergency rescue and other urgent works, with participation of non-toxic substances, acid solutions, alkalis, oil and petroleum products, liquid toxic substances, as well as during operation in water with temperature from 0 to 70 °С are presented. The stability of clothing material packs has been investigated as a transient heat exchange process in a multilayer plate with ideal thermal contact at the joints of the layers. The unlimited plate is heated on both sides under different heat exchange conditions according to Newton’s Law, with constant action of the heat source on one of the surfaces of the hot liquid contacting through the waterproof thin surface. Second surface of the plate interacts with external medium, temperature of which varies according to linear law. At solving the equation of non-stationary thermal conductivity with nonlinear transport coefficients, linearization methods are used based on the approximation of nonlinear coefficients, such that nonlinear equations become approximately linear. The entire heat transfer process is divided into a plurality of small-time intervals within which the transfer coefficients are constant. The zonal method of investigation of non-stationary thermal conductivity in clothing packages establishes equations for calculation of temperature, densities of thermal flows, distribution of temperature across thickness of clothing packages. It has been shown that under accepted calculation simplifications, parameter values are well consistent with the experiment. The composition of the clothing package is proposed, which meets the technical requirements of TУ BY 101114857.082-2015 “Personal Protective Kits”.

Effect of a Heat-Conducting Well Casing on Temperature Distribution in an Observation Well

1979 ◽  
Vol 101 (1) ◽  
pp. 20-27
Author(s):  
P. J. Closmann ◽  
E. R. Jones ◽  
E. A. Vogel
Keyword(s):  
Heat Conduction ◽  
Temperature Distribution ◽  
Heat Source ◽  
Constant Temperature ◽  
Thermal Contact ◽  
Heat Conducting ◽  
Formation Temperature ◽  
Maximum Difference ◽  
Observation Well ◽  
Perfect Thermal Contact

The effect of heat conduction on temperature along the wall of a well casing has been determined by solution of the equations of heat conduction. The casing was assumed to pass vertically through a planar heat source of constant temperature. The casing and formation were assumed to be in perfect thermal contact. Numerical results were obtained for two sizes of steel casing and one size of aluminum casing. At any given distance from the heat source, the casing temperature differs most at early times from the formation temperature computed in the absence of casing. This difference decreases rapidly with time. Furthermore, the maximum difference occurs at greater distances from the heat source as time increases. In general, after about three months of heating, errors in measured temperatures due to conduction along the casing wall are negligible.

Influence of Temperature Distribution on Tighten Force in Tie-Bolt Fastened Rotor With Considering Thermal Contact Conductance

2015 ◽  
Author(s):  
He Peng ◽  
Ning Xu ◽  
Zhansheng Liu
Keyword(s):  
Surface Roughness ◽  
Thermal Expansion ◽  
Temperature Distribution ◽  
Contact Pressure ◽  
Thermal Contact ◽  
Thermal Contact Conductance ◽  
Axial Position ◽  
Contact Conductance ◽  
Pressure Surface ◽  
Axial Temperature

Tighten force has much influence on tie-bolt fastened rotor dynamics. Temperature distribution in tie-bolt fastened rotor results in thermal expansion of rotor and rods. The difference of thermal expansion between rotor and rods causes the variation of bolt load. With considering the thermal contact conductance, the thermal model of tie-bolt fastened rotor was established by finite element method and the axial temperature distribution was obtained. The influences of surface roughness, nominal contact pressure and axial position of contact on axial temperature distribution were analysed. Based on temperature distribution in the tie-bolt fastened rotor, the variation of tighten force was investigated. Results show that nominal contact pressure, surface roughness and axial contact arrange have different influences on the variation of tighten force with temperature.

Two-dimensional finite difference model to study temperature distribution in SST regions of human limbs immediately after physical exercise in cold climate

2015 ◽  
Vol 04 (01) ◽  
pp. 1550002
Author(s):  
Babita Kumari ◽  
Neeru Adlakha
Keyword(s):  
Thermal Stress ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Finite Difference ◽  
Physical Exercise ◽  
Peripheral Region ◽  
Cold Climate ◽  
The Body ◽  
Cylindrical Shape ◽  
Two Dimensional

Thermoregulation is a complex mechanism regulating heat production within the body (chemical thermoregulation) and heat exchange between the body and the environment (physical thermoregulation) in such a way that the heat exchange is balanced and deep body temperatures are relatively stable. The external heat transfer mechanisms are radiation, conduction, convection and evaporation. The physical activity causes thermal stress and poses challenges for this thermoregulation. In this paper, a model has been developed to study temperature distribution in SST regions of human limbs immediately after physical exercise under cold climate. It is assumed that the subject is doing exercise initially and comes to rest at time t = 0. The human limb is assumed to be of cylindrical shape. The peripheral region of limb is divided into three natural components namely epidermis, dermis and subdermal tissues (SST). Appropriate boundary conditions have been framed based on the physical conditions of the problem. Finite difference has been employed for time, radial and angular variables. The numerical results have been used to obtain temperature profiles in the SST region immediately after continuous exercise for a two-dimensional unsteady state case. The results have been used to analyze the thermal stress in relation to light, moderate and vigorous intensity exercise.

CFD-Based Study of Velocity and Temperature Distribution among Rib-Tube in Heat Environment

2014 ◽  
Vol 487 ◽  
pp. 558-561
Author(s):  
Su Hou De ◽  
Zhang Yu Fu ◽  
Che Ji Yong ◽  
Wu Shi Lei ◽  
Xiao Long Wen
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Velocity Distribution ◽  
Engineering Application ◽  
Dispersed Phase ◽  
Wall Function ◽  
Governing Equations ◽  
Theory Analysis

The velocity distribution coupled thermal and fluid flow a rib-tube was studied in this article. Based on theory analysis and numerical simulation, we choose modal and wall function to simulate the flow in rib-tube, velocity to definite the dispersed phase. The governing equations were built and solved by numerical way. The progress of flow and heat exchange in rib-tube, the rules and contours of temperature, velocity were obtained, they shows that, along the rib-tube, velocity was changed with the temperature rising , which could give us a reference for engineering application .

Simulation and Research of a Thermal Type Liquid Flow Sensor

2012 ◽  
Vol 562-564 ◽  
pp. 1213-1217
Author(s):  
Feng Tian ◽  
Zhen Bin Gao ◽  
Yi Cai Sun
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Flow Sensor ◽  
Turbulent Heat Transfer ◽  
Turbulent Heat ◽  
Water Flow Velocity ◽  
Detection Circuit ◽  
Flow Detection

A flow sensor for liquids, based on the principle of fluid-structure heat transfer is presented. The heater and thermistor are integrated and wrapped together as a detector and heat source, allowing heat exchange between the sensor and the fluid. Through numerical simulation, the temperature distribution of the sensor was investigated, under conditions of various flow velocities. The process of turbulent heat transfer in the flow pipe was simulated, the temperature distribution in the sensor was analyzed and compared under different temperature and velocity of the fluid, and the corresponding measuring ranges were determined. The flow detection circuit is designed and the results of water flow velocity tests in the range of (0.01–1)m/s are presented.

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