Effect of inclination angle of a pair of air jets on heat transfer into the flat surface

被引：33
作者：
Attalla, M. [1 ]
Maghrabie, Hussein M. [1 ]
Specht, E. [2 ]
机构：
[1] South Valley Univ, Fac Engn, Dept Mech Engn, Qena 83521, Egypt
[2] Otto Von Guericke Univ, Inst Fluid Dynam & Thermodynam, D-39106 Magdeburg, Germany
来源：
EXPERIMENTAL THERMAL AND FLUID SCIENCE | 2017年 / 85卷
基金：
中国国家自然科学基金;
关键词：
Pair of jets; Inclination angle; Spacing distance; Separation distance; Nusselt number; Maximum heat transfer; INCLINED SURFACE; IMPINGING JETS; IMPINGEMENT; ENHANCEMENT; FLOW;
D O I：
10.1016/j.expthermflusci.2017.02.023
中图分类号：
O414.1 [热力学];
学科分类号：
摘要：
An experimental investigation is performed to study the effect of the inclination angle of air jets on heat transfer from a horizontal surface. A pair of inclined circular jets issuing from the straight pipes of length to diameter ratio of 40 is considered. The inclination angles of 0, 10, 20, 30 45, and 60 are selected while the Reynolds number is varied from 10,000 to 40,000 based on a jet exit diameter. Jets to impingement plate distance (LID) as well as the spacing distance (S/D) are changed from 2 to 8. The results of the temperature contours as well as the Nusselt number contours are illustrated to study the characteristics of heat transfer from a flat surface cooled by a pair of oblique jets. The experimental results show that the maximum magnitude of average heat transfer coefficient is achieved in the range of inclination angle from 10 to 20. Empirical correlations are presented to predict the value of average Nusselt number as a' function of Re, Pr, and theta. Moreover, a comparison between the values of average Nusslet number of the present study and those available in the literature is carried out. (C) 2017 Elsevier Inc. All rights reserved.
引用
收藏
页码：85 / 94
页数：10
相关论文
共 21 条
[1]   Numerical and experimental study of turbulent impinging twin-jet flow [J].
Abdel-Fattah, A. .
EXPERIMENTAL THERMAL AND FLUID SCIENCE, 2007, 31 (08) :1061-1072
[2]   EXPERIMENTAL INVESTIGATION OF HEAT TRANSFER FOR A JET IMPINGING OBLIQUELY ON A FLAT SURFACE [J].
Attalla, M. ;
Salem, M. .
EXPERIMENTAL HEAT TRANSFER, 2015, 28 (04) :378-391
[3]   Effect of nozzle geometry on heat transfer characteristics from a single circular air jet [J].
Attalla, M. ;
Salem, M. .
APPLIED THERMAL ENGINEERING, 2013, 51 (1-2) :723-733
[4]   Heat transfer characteristics from in-line arrays of free impinging jets [J].
Attalla, M. ;
Specht, E. .
HEAT AND MASS TRANSFER, 2009, 45 (05) :537-543
[5]   Heat transfer enhancement in natural convection between vertical and downward inclined wall and air by pulsating jets [J].
Baffigi, Federica ;
Bartoli, Carlo .
EXPERIMENTAL THERMAL AND FLUID SCIENCE, 2010, 34 (07) :943-953
[6]  
Beltaos S., 1976, J HYDRAUL RES, V14, P17, DOI DOI 10.1080/00221687609499685
[7]  
Donovan T. S. O., 2008, INT J HEAT MASS TRAN, V51, P6169
[8]   HEAT-TRANSFER FROM A FLAT SURFACE TO AN OBLIQUE IMPINGING JET [J].
GOLDSTEIN, RJ ;
FRANCHETT, ME .
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME, 1988, 110 (01) :84-90
[9]   Heat transfer characteristics of a planar water jet impinging normally or obliquely on a flat surface at relatively low Reynolds numbers [J].
Ibuki, Kazuya ;
Umeda, Taichi ;
Fujimoto, Hitoshi ;
Takuda, Hirohiko .
EXPERIMENTAL THERMAL AND FLUID SCIENCE, 2009, 33 (08) :1226-1234
[10]   Experimental average Nusselt number characteristics with inclined non-confined jet impingement of air for cooling application [J].
Ingole, S. B. ;
Sundaram, K. K. .
EXPERIMENTAL THERMAL AND FLUID SCIENCE, 2016, 77 :124-131
123