| Author: | Chan, Tin-cheung |
| Title: | Effect of angle on forced convection in air-cooled isosceles triangular duct |
| Degree: | M.Sc. |
| Year: | 1999 |
| Subject: | Heat exchangers Heat -- Transmission Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Mechanical Engineering |
| Pages: | xi, 56, [14] leaves : ill. (some col.) ; 30 cm |
| Language: | English |
| Abstract: | An experimental investigation has been conducted to determine the effect of the corner geometry on forced-convection of four air-cooled horizontal isosceles-triangular-sectioned ducts, which were fabricated with sharp corners, same length and same hydraulic diameter, but different apex angle at fully-developed internal turbulent airflow condition. Hence, to simulate the heat-transfer performance of turbulent airflow through the isosceles-triangular passages in plate-fin type compact heat-exchanger. The entire inner duct walls were uniformly heated and thermally insulated from the ambient. The ducts were constructed with same axial length of 2400mm and hydraulic diameter of 44mm, but with four different apex-angles, namely 15o, 20o, 25o and 30o. The experimental investigations were performed over a wide range of Reynolds number (Re), from 5,000 to 20,000. Non-dimensional correlation was emerged from the experimental results for prediction of the average convective heat-transfer coefficient between a turbulent airflow and the wall of isosceles-triangular duct with a particular apex angle. The exponential expression for Nusselt number (Nu) versus with Reynolds number at constant Prandtl number (Pr = 0.707) as recommended by Leung & Probert [ 9 ], namely Nu = C RDm, where the constant, C, increases from 0.0128 to 0.0135 when the apex angle is increased from 15o to 30o.A term known as the "Total Angle's Reciprocal", 峖T , was employed to facilitate analysing the effect of the corner on the forced-convection occurring in the passage of the isosceles-triangular ducts. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b14792059.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.39 MB | Adobe PDF | View/Open |
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