Düz bir levhaya çarpan sınırlandırılmamış ve sınırlandırılmış dairesel hava jetlerinde ısı transferi etkilerinin incelenmesi

Year 2023, Volume: 12 Issue: 4, 1325 - 1334, 15.10.2023

Haluk Keleş , Yücel Özmen

https://doi.org/10.28948/ngumuh.1310010

Abstract

Bu çalışmada, düz bir yüzeye çarpan sınırlandırılmamış ve sınırlandırılmış türbülanslı dairesel hava jetlerinde çarpma yüzeylerindeki ısı transferi etkileri deneysel olarak incelenmiştir. Çarpma levhası yüzeylerinde termal kamera ile gerçekleştirilen sıcaklık ölçümlerinden, çarpma levhası orta ekseni boyunca sıcaklık dağılımları elde edilmiştir. Elde edilen sıcaklık dağılımlarından, Reynolds sayısının, lüle-levha arası açıklığın ve sınırlayıcı levha durumunun çarpma levhası üzerindeki Nusselt dağılımlarına etkisi araştırılmıştır. İncelenen tüm akış alanlarında, çarpma levhası üzerindeki Nusselt değerlerinin artan Reynolds sayısı ile arttığı, artan lüle-levha arası açıklık ile azaldığı görülmüştür. Akış alanlarında sınırlayıcı levhanın varlığı, çarpma levhası üzerindeki Nusselt değerlerini azaltmaktadır. Sınırlandırılmamış jet durumunda çarpma bölgesindeki Nusselt değerleri sınırlandırılmış jet durumuna kıyasla % 15’e varan oranda daha yüksek elde edilmiştir.

Keywords

Çarpan dairesel jet, Sınırlayıcı levha, Nusselt dağılımı

Investigation of effects of heat transfer in unconfined and confined impinging circular air jets on flat plate

Abstract

In this study, the heat transfer effects on the impingement surfaces of unconfined and confined turbulent circular air jets impinging a flat surface are investigated experimentally. Temperature distributions along the center axis of the impingement plate were obtained from the temperature measurements performed with a thermal camera on the impingement plate surfaces. From the obtained temperature distributions, the effects of Reynolds number, nozzle-to-plate spacing, and the presence of confinement plate on the Nusselt distributions on the impingement plate were investigated. In all flow fields investigated, it was observed that the Nusselt values on the impingement plate increased with increasing Reynolds number and decreased with increasing nozzle-to-plate spacing. The presence of the confinement plate in the flow fields reduces the Nusselt values on the impingement plate. In the unconfined jet case, the Nusselt values in the impingement region were up to 15 % higher than in the confined jet case.

Keywords

Impinging circular jet, Confinement plate, Nusselt distribution

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