Title :

NUMERICAL ANALYSIS OF HEAT TRANSFER INCREASE IN A TUBE WITHALTERNATE SUCCESSIVE GRADUAL WALL DEFORMATIONS

Author(s) :

Zambaux, Julie-Anne [Auteur]
Centre for Energy and Environment [CERI EE - IMT Nord Europe]
JUNIA [JUNIA]
Russeil, Serge [Auteur]
Centre for Energy and Environment [CERI EE - IMT Nord Europe]
Harion, Jean-Luc [Auteur]
Centre for Materials and Processes [CERI MP - IMT Nord Europe]
Laboratoire de Génie Civil et Géo-Environnement (LGCgE) - ULR 4515 [LGCgE]
Bouvier, Pascale [Auteur]
Centre for Energy and Environment [CERI EE - IMT Nord Europe]
JUNIA [JUNIA]

Conference title :

HEFAT2014 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics

City :

Orlando

Country :

France

Start date of the conference :

2014-07-14

HAL domain(s) :

Sciences de l'ingénieur [physics]
Sciences de l'ingénieur [physics]/Mécanique [physics.med-ph]/Thermique [physics.class-ph]

English abstract : [en]

From previous studies, it is known that the use of walldeformations in alternate directions while keeping a quasiconstantcross-section is an efficient way to enhance the heattransfer in a laminar flow regime inside a tube. ...
Show more >From previous studies, it is known that the use of walldeformations in alternate directions while keeping a quasiconstantcross-section is an efficient way to enhance the heattransfer in a laminar flow regime inside a tube. In the presentstudy, the tube cross-section shape gradually changes along thetube length while keeping the same cross section area toprevent flow separation areas thereby limiting pressure drops.These wall deformations create vortical macro-structures insidethe flow that significantly modify the transfer properties. Twogeometrical parameters characterize the tube wall shape: theradial deformation amplitude and its streamwise wavelength.Through a numerical study, the effects of the variation of thesetwo parameters on the flow and on the heat transfer have beenstudied. An important finding is that the ratio between thewavelength and the amplitude holds a significant impact on theobserved results: both the friction and the heat transfer increaseas this deformation ratio decreases. At the same time, a localanalysis of the flow mechanisms has been performed to outlinethe modifications that occur in the flow pattern when the walldeformations are increased. Flow in the entrance region hasalso been specifically considered: it has been found thatgeometrical parameters do have an influence on the lengthneeded for the flow to get fully hydrodynamically andthermally established. Finally a performance analysis has beenconducted to assess, for a given performance criterion, thedeformation parameters that give optimal results. Through thisparametric study, for given Reynolds and Prandtl numbers, analternate wall deformed tube geometry that maximizes the heattransfer without significantly increasing the pressure drops canthus be definedShow less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Collections :

• Laboratoire Génie Civil et géo-Environnement (LGCgE) - ULR 4515

Source :

Harvested from HAL