Rajen Kumar Nayak, Ravi Shankar Prasad, Ujjwal Kumar Nayak, Amit Kumar Gupta

Frontiers in Heat and Mass Transfer (FHMT) 20 - 1 (2023)

Inserting the jet plate between the bottom plate and absorber plate in a flat plate solar air heater has been proposed as an excellent option to enhance the performance of the conventional solar air heater. This research work presents an experimental study of flow and heat transfer in a jet plate solar air heater. Results are presented for the different mass flow rates of air ṁ₁ and ṁ₂, Reynolds number Rej_a2, streamwise pitch of the holes to jet hole diameter X/D, depth of upper channel to jet hole diameter Z₂/D, fixed number of jet hole N and angle of tilt θ. In the present study, it is found that outlet air temperature, collector efficiency, heat transfer coefficient and Nusselt number are higher at lower jet hole diameter, D (6 mm) as compared to higher jet hole diameter, D (8 mm and 10 mm) irrespective of the mass flow rates, ṁ₁ and ṁ₂. The outlet air temperature decreases with increase of mass flow rates of air (ṁ₁ and ṁ₂) and jet hole diameter. Based on the experimental data, the correlation for Nusselt number has been developed.