Thermal-Mechanical Modelling of the Rolling-Plus-Sliding With Frictional Heating of a Locomotive Wheel

1995 ◽  
Vol 117 (3) ◽  
pp. 418-422 ◽  
Author(s):  
V. Gupta ◽  
G. T. Hahn ◽  
P. C. Bastias ◽  
C. A. Rubin
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Frictional Heating ◽  
Finite Element Models ◽  
Steady State Temperature ◽  
Mechanical Modelling ◽  
Computing Effort ◽  
Long Time ◽  
D Model ◽  
Locomotive Wheels

This paper examines finite element models for studying the long time frictional heating of locomotive wheels. The aim is to obtain the temperature distribution and the thermal and residual stresses in the wheel, for given conditions of rolling-plus-sliding, with the least computing effort. Initially a rigorous 3-D model is employed. Then this model is reduced to a much simpler but equivalent 2-D axisymmetric model with reasonable assumptions. It is shown, with the help of the 3-D model, that the actual temperature distribution is fluctuating and exhibits a sharp spike during each wheel rotation. For a part of the cycle the temperature is much higher than the steady state temperature calculated from the 2-D model.

scholarly journals Steady State Temperature Distribution Investigation of HTR Core

2018 ◽  
Vol 962 ◽  
pp. 012040 ◽  
Author(s):  
Sudarmono ◽  
Suwoto ◽  
Syaiful Bakhri ◽  
Geni Rina Sunaryo
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Steady State Temperature

Thermal Convective Instabilities in a Porous Medium

1984 ◽  
Vol 106 (1) ◽  
pp. 137-142 ◽  
Author(s):  
M. Kaviany
Keyword(s):  
Porous Medium ◽  
Steady State ◽  
Temperature Distribution ◽  
Rayleigh Number ◽  
Saturated Porous Medium ◽  
Critical Rayleigh Number ◽  
Linear Stability Theory ◽  
Onset Of Convection ◽  
Long Time ◽  
Nonlinear Temperature

The onset of convection due to a nonlinear and time-dependent temperature stratification in a saturated porous medium with upper and lower free surfaces is considered. The initial parabolic temperature distribution is due to uniform internal heating. The medium is then cooled by decreasing the upper surface temperature linearly with time. Linear stability theory is applied to the more formally developed governing equations. In order to obtain an asymptotic solution for transient problems involving very long time scales, the critical Rayleigh number for steady-state, nonlinear temperature distribution is also obtained. The effects of porosity, permeability, and Prandtl number on the time of the onset of convection are examined. The steady-state results show that the critical Rayleigh number depends only on the ratio of porosity to permeability and when this ratio exceeds a value of one thousand, the critical Rayleigh number is directly proportional to this ratio.

Steady-State Temperature Distribution in a Rotating Roll Subject to Surface Heat Fluxes and Convective Cooling

1981 ◽  
Vol 103 (1) ◽  
pp. 36-41 ◽  
Author(s):  
E. J. Patula
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Cold Rolling ◽  
Heat Input ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Solution Technique ◽  
Convective Cooling ◽  
Roll Temperature ◽  
Steady State Temperature

With the higher rolling speeds used in modern cold-rolling mills, proper roll cooling has become a critical factor in avoiding problems of excessive roll spalling and poor thermal crowning. Poor thermal crowning of rolls can severely affect the shape and profile of sheet and strip products. To determine the influence of cooling practices on roll temperature, a mathematical model was developed that determines the two-dimensional (radial and circumferential) steady-state temperature distribution in a rotating roll subject to constant surface heat input over one portion of the circumference and convective cooling over another portion of the circumference. The model is analytical in nature, as opposed to a direct numerical simulation, which enables extensive parametric studies to be performed conveniently. The solution technique can be used to solve numerous problems involving any combination of surface boundary conditions that have, at most, a linear dependence with respect to the surface temperature. With the use of the principle of superposition, the present solution can be utilized to solve problems where various regions of the surface have constant heat fluxes. Results of the present analysis indicate that for normal cold-rolling situations during steady operation, the penetration of the effects of the surface heating and cooling that occur during every roll revolution is usually less than 4 percent of the radius. Furthermore, the bulk of the roll is at a uniform temperature that can be calculated quite accurately by neglecting all internal temperature gradients. The location of the cooling regions relative to the heat-input regions has little effect on the bulk roll temperature in this situation. This approximation would be useful for computing bulk roll temperature, which could be utilized in future models for determining thermal crowns, but would not be suited for determining accurate temperatures at the roll surface.

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