This paper presents the results of an experimental investigation into the average heat transfer and friction characteristics of gas flow in annuli. The results are measured at five annular passages having a smooth outer tube with inside diameter of 45 mm, wall thickness of 5 mm and length of 3050 mm, and interchangeable inner tubes with total length of 2000 mm and the rough part 540 mm long. The results of the helical-triangular-rib surface geometry are measured for four helix angles (α = 59̀, 2o 45̀̀̀̀̀̀, 4o 32̀, and 6o 17̀̀) all having a relative roughness size (e/d) of 0.1. The helical-rib relative spacings (c/e) equal to 0.54, 1.51, 2.49 and3.47, In addition to the four rough tubes, a smooth tube geometry is tested to validate the experimental procedure. Air is use as a working fluid, encompassing flow range 3900 <Re<44000. The data are correlated in a form to permit performance prediction. The benefits of the roughness for heat exchanger applications are quantitatively established.
Shalaby, M. (2021). Heat Transfer and Friction in Annular Tubes Carrying Gas Flow with Helically-Triangular-Rib Roughness on the Inner Surface.. MEJ- Mansoura Engineering Journal, 12(1), 43-52. doi: 10.21608/bfemu.1987.174521
MLA
M. A. Shalaby. "Heat Transfer and Friction in Annular Tubes Carrying Gas Flow with Helically-Triangular-Rib Roughness on the Inner Surface.". MEJ- Mansoura Engineering Journal, 12, 1, 2021, 43-52. doi: 10.21608/bfemu.1987.174521
HARVARD
Shalaby, M. (2021). 'Heat Transfer and Friction in Annular Tubes Carrying Gas Flow with Helically-Triangular-Rib Roughness on the Inner Surface.', MEJ- Mansoura Engineering Journal, 12(1), pp. 43-52. doi: 10.21608/bfemu.1987.174521
VANCOUVER
Shalaby, M. Heat Transfer and Friction in Annular Tubes Carrying Gas Flow with Helically-Triangular-Rib Roughness on the Inner Surface.. MEJ- Mansoura Engineering Journal, 2021; 12(1): 43-52. doi: 10.21608/bfemu.1987.174521
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