The Temperature Field Around a Spherical Ridge or Trough in a Plane

1992 ◽  
Vol 114 (2) ◽  
pp. 317-325 ◽  
Author(s):  
J. Fransaer ◽  
J. R. Roos
Keyword(s):  
Heat Flux ◽  
Contact Angle ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Flux Distribution ◽  
Spherical Particles ◽  
Heat Flux Distribution ◽  
Conducting Plane ◽  
Temperature Distributions ◽  
Random Array

An analytical solution, which describes the temperature field around a single spherical particle partly embedded in a plane or around a trough making an arbitrary contact angle with a plane, is presented here. The temperature distributions for three cases are studied: the temperature distribution around a conducting bowl or trough, the temperature distribution around a non-conducting bowl or trough present in a conducting plane, and the temperature profile around a conducting bowl or trough conducting heat toward a sink at infinity. The normalized heat flux distribution on the plane and particle is presented. The various incremental resistances caused by a single and a dilute planar random array of truncated spherical particles are also derived.

scholarly journals Thermal analysis in thin-film fluid regions of rectangular microgroove

2018 ◽  
Vol 22 (2) ◽  
pp. 899-897
Author(s):  
Xiaohong Gui ◽  
Xiange Song ◽  
Baisheng Nie
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Contact Angle ◽  
Film Thickness ◽  
Flux Distribution ◽  
Total Heat ◽  
Heat Flux Distribution ◽  
Total Heat Transfer ◽  
Thin Film Thickness

The effects of contact angle and superheat on thin-film thickness and heat flux distribution occurring in a rectangle microgroove are numerically simulated. Accordingly, physical, and mathematical models are built in detail. Numerical results indicate that meniscus radius and thin-film thickness increase with the improvement of contact angle. The heat flux distribution in the thin-film region increases non-linearly as the contact angle decreases. The total heat transfer through the thin-film region increases with the improvement of superheat, and decreases as the contact angle increases. When the contact angle is equal to zero, the heat transfer in the thin-film region accounts for more than 80% of the total heat transfer. Intensive evaporation in the thin-film region plays a key role in heat transfer for the rectangle capillary microgroove. The liquid with higher wetting performance is more capable of playing the advantages of higher intensity heat transfer in thin- film region. The current investigation will result in a better understanding of thin- -film evaporation and its effect on the effective thermal conductivity in the rectangle microgroove.

scholarly journals Integrated study of flue gas flow and superheating process in a recovery boiler using computational fluid dynamics and 1D-process modeling

TAPPI Journal ◽  
2020 ◽  
Vol 19 (6) ◽  
pp. 303-316
Author(s):  
KUNAL KUMAR ◽  
VILJAMI MAAKALA ◽  
VILLE VUORINEN
Keyword(s):  
Fluid Dynamics ◽  
Heat Flux ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Flue Gas ◽  
Gas Flow ◽  
Flux Distribution ◽  
Heat Flux Distribution ◽  
Recovery Boilers ◽  
Material Temperature

Superheaters are the last heat exchangers on the steam side in recovery boilers. They are typically made of expensive materials due to the high steam temperature and risks associated with ash-induced corrosion. Therefore, detailed knowledge about the steam properties and material temperature distribution is essential for improving the energy efficiency, cost efficiency, and safety of recovery boilers. In this work, for the first time, a comprehensive one-dimensional (1D) process model (1D-PM) for a superheated steam cycle is developed and linked with a full-scale three-dimensional (3D) computational fluid dynamics (CFD) model of the superheater region flue gas flow. The results indicate that: (1) the geometries of headers and superheater platens affect platen-wise steam mass flow rate distribution (3%–7%); and (2) the CFD solution of the 3D flue gas flow field and platen heat flux distribution coupled with the 1D-PM affect the platen-wise steam superheating temperature (45%–122%) and material temperature distribution (1%–6%). Moreover, it is also found that the commonly-used uniform heat flux distribution approach for the superheating process is not accurate, as it does not consider the effect of flue gas flow field in the superheater region. These new observations clearly demonstrate the value of the present integrated CFD/1D-PM modeling approach.

Inverse Thermal Analysis of a Coke Drum Using a Bayesian Probabilistic Approach

2015 ◽  
Author(s):  
Edrissa Gassama ◽  
Charles Panzarella ◽  
Jeffrey Cochran
Keyword(s):  
Heat Flux ◽  
Finite Element ◽  
Temperature Distribution ◽  
Flux Distribution ◽  
Thermal Stresses ◽  
Heat Conduction Problem ◽  
Probabilistic Approach ◽  
Operating Conditions ◽  
Heat Flux Distribution ◽  
Posterior Probability Distribution

There is much interest in predicting the optimal operating conditions of a coke drum in order to extend its life and optimize both maintenance and repair. Typically, only temperature measurements on the outer surface of the wall are available from monitoring. In order to predict damage due to thermal stresses and other mechanisms, the temperature distribution through the wall is required. This could be determined if the heat flux on the inner surface of the wall were known, but this is difficult to obtain directly. In this paper, the heat flux distribution on the inner wall is determined solely from thermocouple measurements taken on the outside of the wall by solving a stochastic inverse heat conduction problem (IHCP). A finite element analysis is used to solve the forward thermal problem, and a Bayesian inference approach is used to model the posterior probability distribution of the heat flux. A newly developed probabilistic sampling technique known as the Particle Raking Algorithm (PRA) is found to be quite effective at solving this inverse problem. Once determined, the heat flux distribution is then applied as a boundary condition for the finite element model to determine the through-wall temperature distribution.

Temperature Distributions and Thermal Stresses in Asymmetrically Heat Radiated Tubes

1986 ◽  
Vol 53 (1) ◽  
pp. 116-120 ◽  
Author(s):  
T. Fett
Keyword(s):  
Heat Flux ◽  
Half Space ◽  
Flux Distribution ◽  
Thermal Stresses ◽  
Tube Wall ◽  
Stress Distributions ◽  
Heat Flux Distribution ◽  
Temperature Distributions

The transient and stationary temperature distributions in a tube wall caused by an asymmetrical heat flux distribution are evaluated. The results are represented for the case of a heat radiating half-space. In addition, the accompanying stress distributions are computed.

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