FARKLI GEOMETRİDE AKIŞ YÖNLENDİRİCİLER VE ÇARPAN JET KULLANARAK YÜKSEK ISI AKILI BİR YÜZEYDEN OLAN ISI TRANSFERİNİN İYİLEŞTİRİLMESİ

MUSTAFA KILIÇ, ŞENOL BAŞKAYA
2017 Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi  
In this study; the enhancement of heat transfer from a surface with constant heat flux using an impinging jet and different shapes of vortex promoters was investigated numerically. Firstly, fluid flow and heat transfer in a channel were investigated for different Reynolds numbers, and ratio of channel height to nozzle hydraulic diameter (H/Dh), without using vortex promoters. Afterwards, effects of cylindrical, square and triangular vortex promoters on fluid flow and heat transfer for ratio of
more » ... istance of vortex promoter to jet center to nozzle hydraulic diameter were investigated. In the last phase; effects of second group of vortex promoters were investigated on heat transfer and fluid flow. As a result; by using impinging jets and vortex promoters an increase of 28% on heat transfer from the surface can be observed according to the condition without vortex promoter. With increasing Reynolds number an increase on heat transfer was observed. Decreasing the channel height does not increase the heat transfer significantly. For the cylindrical vortex promoters maximum local Nusselt number is obtained at L/Dh=1.4. The most effective heat transfer is obtained with triangular vortex promoters. Using second group of vortex promoters can cause an increase of 36.1 % on heat transfer locally, but cannot cause a prominent increase on heat transfer along the target plate generally. Additionally, it is observed that the low Reynolds k-ɛ turbulent model can represent temperature variation and flow characteristic quite well.
doi:10.17341/gazimmfd.337616 fatcat:dfsjh2ywkvad7hpmjfytserrxi