Finite-Volume Heat Transfer Model of the Nano Electrical Discharge Machining Process

Abstract. DDGS is often transported in railcars and trucks from the ethanol plants to the feed mills and animal farms. During unloading, flowability of DDGS is often reduced due to caking of DDGS bulk. Based on published research, the environmental relative humidity, DDGS glass transition temperature, syrup content, and duration of cooling of DDGS piles influence the caking behavior of DDGS. The objective of this study was to develop and validate a heat transfer model for predicting the cooling pattern of DDGS piles. A finite volume method approach was used to develop the heat transfer model. Ergun’s equation was used to implement airflow resistance in the porous media of the DDGS bulk. The heat transfer inside the pile was simulated for winter (6°C) and summer (24°C) ambient conditions. The model agreed well with the experimental temperature measurements from the three sets of experiments with two sizes of experimental piles. The overall predicted temperatures were 2.7°C and 0.7°C higher than the observed temperatures for small- and medium-size experimental piles, respectively. This heat transfer model could be used to predict the temperature variations in DDGS bulk during storage and as a measure to predict the caking behavior. Keywords: Caking, DDGS, Finite volume method, Heat transfer.

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Transient linear analytical heat transfer model for a building, validation with a non-linear coupled finite volume code

Thermal Science and Engineering Progress ◽

10.1016/j.tsep.2020.100756 ◽

2020 ◽

Vol 20 ◽

pp. 100756

Author(s):

Anas El Maakoul ◽

Alain Degiovanni ◽

Zineb Bouhssine

Keyword(s):

Heat Transfer ◽

Finite Volume ◽

Heat Transfer Model ◽

Transfer Model ◽

Non Linear

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The Experimental and Theoretical Evaluation of an Indirect Cooling System for Machining

Journal of Heat Transfer ◽

10.1115/1.4002446 ◽

2010 ◽

Vol 133 (3) ◽

Cited By ~ 19

Author(s):

Jay C. Rozzi ◽

John K. Sanders ◽

Weibo Chen

Keyword(s):

Heat Transfer ◽

Tool Life ◽

Cutting Tool ◽

Cooling System ◽

Heat Transfer Model ◽

Machining Process ◽

Working Fluid ◽

Transfer Model ◽

Cutting Fluids ◽

Maximum Heat

Cutting fluids have been used in machining processes for many years to decrease the temperature during machining by spraying the coolant into the machining zone directly on the cutting tool and the part. This has the effect of decreasing the tool temperature, which increases tool life and improves the part quality. These benefits come with significant drawbacks. Cutting fluids are environmentally unfriendly, costly, and potentially toxic. An alternative that has been evaluated in this paper is an internal cooling system (ICS) for lathe turning, which cools the cutting tool using a very small amount of an inert, cryogenic working fluid routed through a microchannel heat exchanger (MHX) that is mounted beneath the cutting tool insert. The working fluid absorbs the heat generated during the machining process after which it is harmlessly vented to the environment. This indirect cooling technique results in an environmentally friendly machining process that uses no cutting fluids, enables increased processing speed, and reduces manufacturing costs. An approximate heat transfer model was developed and used to predict the tool life as a function of the tool cooling approach for various speeds. Machining experiments were completed to validate the heat transfer model and confirm that the ICS can significantly improve tool life relative to conventional flood cooling. The validated model was then used to evaluate alternative cooling approaches using the ICS. It was found that the use of a cryogenic working fluid can significantly improve tool life at all cutting speeds but that the latent heat capacity of the working fluid should exceed the expected maximum heat transfer rate into the tool. This work established that the ICS approach is an effective means to increase tool life without the disadvantages associated with external cryogenic cooling methods.

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RADIATIVE HEAT TRANSFER MODEL IN ARBITRARY ENCLOSURES BY RAY-TRACING

Proceedings of the Second International Symposium on Radiation Transfer ◽

10.1615/ichmt.1997.intsymliqtwophaseflowtranspphenchtradtransfproc.60 ◽

1997 ◽

Cited By ~ 2

Author(s):

Wen Cai

Keyword(s):

Heat Transfer ◽

Ray Tracing ◽

Radiative Heat Transfer ◽

Radiative Heat ◽

Heat Transfer Model ◽

Transfer Model

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A Heat Transfer Model for Concentrating Silicon Solar Cells in a Spectrally Splitting Hybrid Receiver

Proceedings of the 15th International Heat Transfer Conference ◽

10.1615/ihtc15.sol.009067 ◽

2014 ◽

Cited By ~ 1

Author(s):

Ahmad Mojiri ◽

Cameron Stanley ◽

Elizabeth Thomsen ◽

Vernie Everett ◽

Andrew Blakers ◽

...

Keyword(s):

Heat Transfer ◽

Solar Cells ◽

Heat Transfer Model ◽

Silicon Solar Cells ◽

Transfer Model

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Theoretical Post-Dryout Heat Transfer Model

International Journal of Computational Physics Series ◽

10.29167/a1i1p142-150 ◽

2018 ◽

Vol 1 (1) ◽

pp. 142-150

Author(s):

Murat Tunc ◽

Ayse Nur Esen ◽

Doruk Sen ◽

Ahmet Karakas

Keyword(s):

Heat Transfer ◽

Droplet Diameter ◽

Heat Transfer Model ◽

Transfer Model ◽

Operating Pressure ◽

Vertical Pipe ◽

Two Phase ◽

Experimental Values ◽

Reactor Operating ◽

Coolant System

A theoretical post-dryout heat transfer model is developed for two-phase dispersed flow, one-dimensional vertical pipe in a post-CHF regime. Because of the presence of average droplet diameter lower bound in a two-phase sparse flow. Droplet diameter is also calculated. Obtained results are compared with experimental values. Experimental data is used two-phase flow steam-water in VVER-1200, reactor coolant system, reactor operating pressure is 16.2 MPa. On heater rod surface, dryout was detected as a result of jumping increase of the heater rod surface temperature. Results obtained display lower droplet dimensions than the experimentally obtained values.

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