Indian Journal of Science and Technology

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Heat Transfer Enhancement in Solar Air Heater


Affiliations
1 Dept. of Mechanical Engineering, M.A.N.I.T., Bhopal-462051, Madhya Pradesh, India
 

This paper presents results of an experimental investigation of heat transfer in rectangular duct with repeated ribs in Wcontinuous pattern. The ribs in W-pattern have been tested for both pointing upstream (W-up) and downstream (Wdown) to the flow. The duct has width to height ratio of 8, relative roughness pitch of 10, relative roughness height of 0.03375, angle of attack of ribs in W-pattern is 45° and Reynolds number ranges from 2300-14000. Roughened wall of the duct is uniformly heated while the remaining three walls are insulated. These conditions correspond closely to those found in solar air heaters. The heat transfer results have been compared with those for smooth ducts under similar flow and thermal boundary condition. Enhancement of heat transfer by providing W-shape roughness is 2.39 times to that of smooth plate for W-down ribs and 2.21 times to that of smooth plate for W-up ribs respectively.

Keywords

Solar Air Heater, Heat Transfer And W-shape Rib Roughness
User

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  • Heat Transfer Enhancement in Solar Air Heater

Abstract Views: 424  |  PDF Views: 116

Authors

A. M. Lanjewar
Dept. of Mechanical Engineering, M.A.N.I.T., Bhopal-462051, Madhya Pradesh, India
J. L. Bhagoria
Dept. of Mechanical Engineering, M.A.N.I.T., Bhopal-462051, Madhya Pradesh, India
R. M. Sarviya
Dept. of Mechanical Engineering, M.A.N.I.T., Bhopal-462051, Madhya Pradesh, India

Abstract


This paper presents results of an experimental investigation of heat transfer in rectangular duct with repeated ribs in Wcontinuous pattern. The ribs in W-pattern have been tested for both pointing upstream (W-up) and downstream (Wdown) to the flow. The duct has width to height ratio of 8, relative roughness pitch of 10, relative roughness height of 0.03375, angle of attack of ribs in W-pattern is 45° and Reynolds number ranges from 2300-14000. Roughened wall of the duct is uniformly heated while the remaining three walls are insulated. These conditions correspond closely to those found in solar air heaters. The heat transfer results have been compared with those for smooth ducts under similar flow and thermal boundary condition. Enhancement of heat transfer by providing W-shape roughness is 2.39 times to that of smooth plate for W-down ribs and 2.21 times to that of smooth plate for W-up ribs respectively.

Keywords


Solar Air Heater, Heat Transfer And W-shape Rib Roughness

References





DOI: https://doi.org/10.17485/ijst%2F2010%2Fv3i8%2F29908