Heat transfer enhancement, flow visualization and friction characteristics in rib-roughened channels

dc.contributor.authorStasiek, A.
dc.contributor.authorJewartowski, M.
dc.contributor.authorMikielewicz, D.
dc.contributor.authorStasiek, J.
dc.date.accessioned2014-06-13T10:53:55Z
dc.date.available2014-06-13T10:53:55Z
dc.date.issued2011
dc.description.abstractPaper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.en_US
dc.description.abstractIn the last two decades thermochromic liquid crystal (TLS), true-color digital image processing and laser anemometry (PIV) have been successfully used in non-intrusive, technical and heat and mass transfer studies and applications. The aim of the paper is to asses the state of the art in the exploration of heat transfer control by transverse vortex generators. They are able to increase heat transfer by several hundred percent. Prior to the use of vortices to influence heat transfer it must be known how different vortices are generated and controlled and how they interact with the original or base flow and temperature field. Liquid crystals were used to determinate the distribution of surface temperature and then evaluation of heat transfer coefficient or the Nusselt number. The flow pattern produced by transverse vortex generators (rib-roughened passages) was visualized using a planar beam of double-impulse laser tailored by a cylindrical lens and oil particles. Sequential images of particles in the cross sectional plane taken with CCD video camera from the downstream side the flow were stored on a personal computer to obtain distributions of velocity vectors by means of the PIV method. Local and average Nusselt numbers, friction factors and velocity fields are presented for rectangular channels with an aspect ratio of 6.35 and five types of transverse vortex generators which were brought to required temperatures by hot film method. The pitch-to-height-ratio of the ribs was 11.en_US
dc.description.librarianmp2014en_US
dc.format.extent7 pagesen_US
dc.format.mediumPDFen_US
dc.identifier.citationStasiek, A, Jewartowski, M, Mikielewicz, D & Stasiek, J 2011, 'Heat transfer enhancement, flow visualization and friction characteristics in rib-roughened channels', Paper presented to the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.en_US
dc.identifier.urihttp://hdl.handle.net/2263/40172
dc.language.isoenen_US
dc.publisherInternational Conference on Heat Transfer, Fluid Mechanics and Thermodynamicsen_US
dc.relation.ispartofHEFAT 2011en_US
dc.rightsUniversity of Pretoriaen_US
dc.subjectHeat transfer enhancementen_US
dc.subjectFlow visualizationen_US
dc.subjectFriction characteristicsen_US
dc.subjectRib-roughened channelsen_US
dc.subjectHeat transferen_US
dc.subjectFluid Mechanicsen_US
dc.subjectThermodynamicsen_US
dc.subjectThermochromic liquid crystalen_US
dc.subjectTLSen_US
dc.subjectTrue-color digital image processingen_US
dc.subjectLaser anemometryen_US
dc.subjectTransverse vortex generatorsen_US
dc.subjectDouble-impulse laseren_US
dc.subjectFriction factorsen_US
dc.subjectVelocity fieldsen_US
dc.subjectNusselt numbersen_US
dc.titleHeat transfer enhancement, flow visualization and friction characteristics in rib-roughened channelsen_US
dc.typePresentationen_US

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
stasiek_heat_2014.pdf
Size:
469.23 KB
Format:
Adobe Portable Document Format
Description:
Presentation

License bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description: