Measurements of Heat Transfer and Fluid Flow in a Rectangular Duct with Different Types of Rib-Turbulators.

Morad, K. A.; El-Sawaf, I. A.

doi:10.21608/bfemu.2021.142968

Measurements of Heat Transfer and Fluid Flow in a Rectangular Duct with Different Types of Rib-Turbulators.

Document Type : Research Studies

Authors

K. A. Morad ¹
I. A. El-Sawaf ²

¹ Mechanical Power Department., Faculty of Engineering., Suez Canal University., Port Said., Egypt.

² Mechanical Power Dept., Faculty of Engineering., Suez Canal University., Port Said., Egypt.

10.21608/bfemu.2021.142968

Abstract

Experiments are conducted to study the heat transfer and friction in a rectangular duct roughened by arrays of alternate ribs (square-, triangle-. and circle-shaped ribs). The Reynolds number Re based on duct hydraulic diameter rages from 12.000 to 60.000. whereas the rib pitch-to-height ratio (P/h) varies from 6 to 18. To understand the mechanism of heat transfer enhancement the measurements of streamwise mean velocities are also conducted in the square-ribbed duct. The results show that the flow of air through the ribbed duct becomes periodically fully developed after the third rib from the duct inlet. The data indicate also that the triangular type ribs have a substantially higher heat transfer performance than any other ribs in the studied range. The experimental results show that the heat transfer enhancement factors are greater than the friction factor ratios associated with the use of rib-turbulators in the rectangular ducts. Also, the rib conductivity affects significantly on the heat transfer enhancement factor. Correlations for friction and heat transfer in square-ribbed ducts are developed to account for rib spacing to height ratio and flow Reynolds number.

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