Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
CFD in the design of gas quenching furnace
KTH, School of Engineering Sciences (SCI), Mechanics.
2005 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

This thesis focuses on the numerical and theoretical studies of gas quenching in industrial furnaces. Gas quenching is the rapid cooling of metal pieces, aiming at forcing a phase transformation of the metal structure to improve its mechanical properties. The numerical methodology has been evaluated with respect to the desired accuracy and different aspects of the flow with importance for achieving an optimized process have been investigated. Initially, attention was paid to the flow and heat transfer fields both in an empty furnace and in a furnace loaded with different charges with the objective to study the influence of the charge configuration on the flow and heat transfer uniformity. This study led to the identification of several possible improvements, which are currently being implemented by the industrial partners of this project. As earlier studies had shown the importance of flow uniformity on the quality of the heat treatment, the subsequent work focused substantially on the flow uniformity upstream of the quenching zone resulting in design recommendations for the particular type of furnace under consideration. The dependence of the performance of the coolant medium on its composition was investigated theoretically and an analysis of most important parameters was carried out. Improved knowledge of the effect of gas mixture composition on heat transfer was added to the body of knowledge already available.

Place, publisher, year, edition, pages
Stockholm: KTH , 2005. , xii, 47 p.
Series
Trita-MEK, ISSN 0348-467X ; 2005:12
Keyword [en]
Numerical analysis, Gas quenching, modeling, CFD, gas mixtures, uniformity.
Keyword [sv]
Numerisk analys
National Category
Computational Mathematics
Identifiers
URN: urn:nbn:se:kth:diva-239OAI: oai:DiVA.org:kth-239DiVA: diva2:8023
Public defence
2005-06-16, D2, D, Lindstedsvägen 5, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20101019Available from: 2005-05-31 Created: 2005-05-31 Last updated: 2010-10-19Bibliographically approved
List of papers
1. On hydrodynamics within gas quenching chamber
Open this publication in new window or tab >>On hydrodynamics within gas quenching chamber
2004 (English)In: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774Article in journal (Other academic) Submitted
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-5200 (URN)
Note
QS 20120316Available from: 2005-05-31 Created: 2005-05-31 Last updated: 2017-12-04Bibliographically approved
2. On Heat Transfer within Gas Quenching Furnace
Open this publication in new window or tab >>On Heat Transfer within Gas Quenching Furnace
2005 (English)In: IASME Transactions, 2005Conference paper, Published paper (Refereed)
Abstract [en]

Gas quenching in an industrial furnace is considered. The flow and thermal fields in the furnace withtwo different charges, plates and cylinders, in axial flow are studied numerically. Details of the thermal fieldcharacteristics are presented. A variation in heat transfer of maximum 125 % is observed in the whole basket, themaximum heat transfer being obtained on the first bodies of the charge. The heat transfer is found to be uniformlydistributed in the middle of the charge, with mean values 50 % higher than on the sides. Recommendations forimprovement of current vacuum quenching furnaces are proposed.

Keyword
Quench chamber, heat transfer uniformity, furnace design, hydrodynamic effects, axial flow.
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-5201 (URN)
Note
QC 20101019Available from: 2005-05-31 Created: 2005-05-31 Last updated: 2010-10-19Bibliographically approved
3. CFD for design of gas quenching furnace
Open this publication in new window or tab >>CFD for design of gas quenching furnace
2004 (English)In: Proceedings of the 17th Nordic Seminar on Computational Mechanics, 2004, 62-65 p.Chapter in book (Other academic)
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-5202 (URN)
Note
QC 20101019Available from: 2005-05-31 Created: 2005-05-31 Last updated: 2012-03-22Bibliographically approved
4. Computational Study of Velocity Distribution for Designing some Gas Quench Chamber and Furnace Ducts
Open this publication in new window or tab >>Computational Study of Velocity Distribution for Designing some Gas Quench Chamber and Furnace Ducts
2005 (English)In: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 155, no Part 2 Sp. Iss. SI, 1727-1733 p.Article in journal (Refereed) Published
Abstract [en]

Gas cooled quenching and many other applications require high-speed uniform-velocity flows, with minimal pressure drop. The flow ducting geometry is often rather complex, with flow splitting, 90-180 degrees bends, and circular-to-rectangular cross-section transition ducts (the latter are used, for example, between the circular blower duct and the rectangular quenching baskets). Similar situations exist in forced convection furnaces. To provide design guidance in the choice of such ducts, and focusing primarily on circular-to-rectangular transition ducts. the flow was modelled and computed, and the results were successfully validated. Sensitivity of the velocity uniformity and pressure drop with respect to the primary geometric parameters, pressure, and Reynolds numbers was examined in the range (1.3) 10(5) # Re # (7.8)10(5), with an ultimate objective to produce optimal designs. For a length-to-diameter ratio AL = L/D < 1.0, flow nonuniformity at the exit plane and pressure drop are increased by 33 and 83%, respectively, as the aspect ratio (rectangular duct width-to-height) AR decreases from 4 to 1. Increasing AR beyond 1.5 leads to linearly increasing nonuniformity and pressure drops. A diverging-contracting duct has proven to lead to lesser nonuniformity, while it did not influence the pressure drop. Increasing the inlet pressure from 1 to 20 bar led to a decrease in flow distortion by 11% at the duct exit planes. At atmospheric pressure, increasing the Reynolds number from (1.3)10(5) to (7.8)10(5) increased distortion by 8%. Some preliminary design recommendations for circular-to-rectangular duct transitions are to try and keep AL > 1 and AR < 1.5.

Keyword
circular-to-rectangular duct transitions, duct flow, duct bends, quench chamber design, velocity uniformity, furnace design
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-5203 (URN)10.1016/j.jmatprotec.2004.04.335 (DOI)000225845800096 ()2-s2.0-10044221822 (Scopus ID)
Note
QC 20101019 QC 20110920Available from: 2005-05-31 Created: 2005-05-31 Last updated: 2017-12-04Bibliographically approved
5. On the influence of gas mixture composition on gas quenching uniformity and mean
Open this publication in new window or tab >>On the influence of gas mixture composition on gas quenching uniformity and mean
(English)Manuscript (Other academic)
Abstract [en]

The use of gas mixtures is widely spread in today's industry. The fields of application go from cooling within refrigerators to the deep freezing of meat balls. One particular application is within the industry of gas heat treating of metal pieces. Such heat treatment involves the cooling of metal pieces, called quenching. The present work investigates the dependence of the performance of a given gas mixture on the geometry of the metal pieces to quench. The heat transfer coefficient and the convection Nusselt number across a short cylinder (D = 150 mm, L = 300 mm) in axial flow for mixtures of hydrogen and nitrogen were computed for six Reynolds numbers in the range 2.0 10(4) to 2.0 10(5). The Nusselt number decreased continually with increasing hydrogen content. Since the existing correlations did not adequately represent the calculated data, modified correlations were developed to describe the influence of transport properties and flow pararmeters on the convective heat transfer over the front and lateral surfaces of the cylinder These correlations are valid for the range of Reynolds numbers 2.0 104 to 2.0 105 and in the range of Prandtl numbers 0.4 to 0.73. A relation giving the heat transfer uniformity as a function of the Reynolds number and Prandtl number of the gas mixture flowing around the cylinder in axial flow has been developed. This correlation is valid within the same range of Reynolds and Prandtl numbers previously given.

Keyword
thermal-conductivity, viscosity, helium
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-5204 (URN)
Note
QC 20101019Available from: 2005-05-31 Created: 2005-05-31 Last updated: 2010-10-19Bibliographically approved
6. Heat transfer correlation within gas quenching chamber
Open this publication in new window or tab >>Heat transfer correlation within gas quenching chamber
(English)Manuscript (Other academic)
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-5205 (URN)
Note
QC 20101019Available from: 2005-05-31 Created: 2005-05-31 Last updated: 2010-10-19Bibliographically approved
7. Large eddy simulation of flow and heat transfer over a cylinder in axial flow
Open this publication in new window or tab >>Large eddy simulation of flow and heat transfer over a cylinder in axial flow
(English)Manuscript (Other academic)
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-5206 (URN)
Note
QC 20101019Available from: 2005-05-31 Created: 2005-05-31 Last updated: 2010-10-19Bibliographically approved

Open Access in DiVA

fulltext(2829 kB)2527 downloads
File information
File name FULLTEXT01.pdfFile size 2829 kBChecksum MD5
a8b879f3992ca135f1b75783c3b3e92bbd662073880ef5bba0d21241d184532f508fc38d
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Macchion, Olivier
By organisation
Mechanics
Computational Mathematics

Search outside of DiVA

GoogleGoogle Scholar
Total: 2529 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 1070 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf