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CFD Analysis on Rectangular Shaped Variable Height Turbulators Fitted in a Solar Air Heater for Improved Thermal Performance

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There have been various studies on the effect of turbulators of different shapes integrated with the absorber plate's underside for improved performance. However, a study on rectangular profiled variable height turbulators along the flow direction is not available. In this paper, an attempt has been made to explore in detail this aspect. The roughness of different kinds on the heat transfer surface mainly creates turbulence and breaks the laminar sub-layer, enhancing the heat transfer rate. In the present work, a solar air heater's performance incorporated rectangular profiled variable height turbulators of different configurations, i.e. increasing height turbulators, decreasing height turbulators and constant height turbulators, are being numerically investigated. For the base model, i.e. without any turbulators, a numerical and experimental analysis has been carried to establish the present analysis's overall validity. All tested turbulators show better performance compared to the base model. Configuration, which has to decrease in height towards the flow direction, shows relatively higher performance in terms of heat transfer coefficient, outlet temperature, and thermohydraulic enhancement factor than that of the other configurations. It is found from the analysis that for decreasing height turbulators, there is an enhancement of 21% to 0.2% for the Reynolds number from 3000 to 15000, respectively. For the higher Reynolds number above 15000, the THEF will be lesser than the base model.
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Solar Air Heater; Nusselt Number; Thermo-Hydraulic Enhancement Factor; Turbulator

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Palacios, A., Ramos, O., Amaya, D., Thermal Performance Study of the Fluid of a Collector Using Finite Elements with Computational Tools (CFD), (2018) International Review of Mechanical Engineering (IREME), 12 (2), pp. 189-195.

Lahbari, M., Fahloul, D., Experimental Study and Mathematical Modelling of Loquat Drying: Effect of the Drying Method on Quality, (2020) International Review of Mechanical Engineering (IREME), 14 (3), pp. 208-217.

Anbuchezhian, N., Velmurugan, T., Priyadharshini, G., Krishnamoorthy, R., Novel Design of Hybrid Steam Turbine Reflector Based Controller for Solar Power Plant, (2020) International Review of Mechanical Engineering (IREME), 14 (9), pp. 572-578.

Manjunath, M.S., Karanth, K.V. and Sharma, N.Y., Numerical analysis of the influence of spherical turbulence generators on heat transfer enhancement of flat plate solar air heater. Energy, 121, pp.616-630, 2017.

Kumar, R., Geol, V. and Kumar, A, A parametric study of the 2D model of solar air heater with elliptical rib roughness using CFD. Journal of Mechanical Science and Technology, 31(2), pp.959-964, 2017.

Henaoui, M., Aliane, K., Study on Solar Air Collector with Perforated Strips in the Baffles, (2019) International Review of Mechanical Engineering (IREME), 13 (4), pp. 249 255.

Elgadi, A., Tan, Y., Tai, V., Thermal Performance Evaluation of Binary Fatty Acid/Expanded Graphite Composite as a Thermal Storage Medium for Solar Air Heater, (2020) International Review of Mechanical Engineering (IREME), 14 (10), pp. 626-634.

Mahmoud, A., Yahya, Z., Improvement in the Performance of a Solar Hot Air Generator Using a Circular Cone, (2019) International Review of Mechanical Engineering (IREME), 13 (8), pp. 481-492.

Satam, A., Raibhole, V., A Comparative Study of the Enhancement of Heat Transfer by Delta Wing Vortex Generators and V-Shaped Dimples Using Experimentation and CFD, (2017) International Review of Mechanical Engineering (IREME), 11 (10), pp. 769-773.

Antony, A.L., Shetty, S.P., Madhwesh, N., Sharma, N.Y. and Karanth, K.V., 2020. Influence of stepped cylindrical turbulence generators on the thermal enhancement factor of a flat plate solar air heater. Solar Energy, 198, pp.295-310.

Shetty, S.P., Madhwesh, N. and Karanth, K.V., 2021. Numerical analysis of a solar air heater with a circular perforated absorber plate. Solar Energy, 215, pp.416-433.

Wang, D., Liu, J., Liu, Y., Wang, Y., Li, B. and Liu, J., 2020. Evaluation of the performance of an improved solar air heater with "S" shaped ribs with the gap. Solar Energy, 195, pp.89-101.

Nidhul, K., Kumar, S., Yadav, A.K. and Anish, S., 2020. Enhanced thermo-hydraulic performance in a V-ribbed triangular duct solar air heater: CFD and exergy analysis. Energy, 200, p.117448.

Srivastava, A., Chhaparwal, G.K. and Sharma, R.K., 2020. Numerical and experimental investigation of different rib roughness in a solar air heater. Thermal Science and Engineering Progress, 19, p.100576.

Saravanakumar, P.T., Somasundaram, D. and Matheswaran, M.M., 2020. Exergetic investigation and optimization of arc-shaped rib roughened solar air heater integrated with fins and baffles. Applied Thermal Engineering, 175, p.115316.

Benaouda, N. E., Khellaf, A. and Zeghmati, B, Modeling, simulation and experimental validation of a typical flat plate air-heating collector for drying purposes, Proceedings of 2015 IEEE International Renewable and Sustainable Energy Conference, IRSEC 2015, 2016.

Maurya, R. S. and Ansari, Z. A. J, Effect of flow and geometry parameters on solar air heater performance, THERMINIC 2016 - 22nd International Workshop on Thermal Investigations of ICs and Systems, pp. 319–322, 2016.

Ravi, R.K. and Saini, R.P., 2016. Experimental investigation on the performance of a double pass artificial roughened solar air heater duct having roughness elements of the combination of discrete multi V-shaped and staggered ribs. Energy, 116, pp.507-516.

Hans, V. S., Gill, R. S. and Singh, S., Heat transfer and friction factor correlations for a solar air heater duct roughened artificially with broken arc ribs, Experimental Thermal and Fluid Science, Vol 80, pp 77-89, 2017.

Shuilian Li, Hui Wang, Xiangrui Meng, Xinli Wei, Comparative study on the performance of a new solar air collector with different surface shapes, Applied Thermal Engineering, Vol 114, pp 639 – 644, 2017.

Arunkumar, H.S., Kumar, S. and Karanth, K.V., Analysis of a solar air heater for augmented thermohydraulic performance using helicoidal spring shaped fins-A numerical study. Renewable energy, 160, pp.297-311, 2020.

Kushmeet, K., Prajapati, D. R. and Samir, S. (2016) Heat Transfer and Friction Factor Correlations Development for Solar Air Heater Duct, Experimental Thermal and Fluid Science, Vol 82, pp 249-261, 2017.

Qader, B.S., Supeni, E.E., Ariffin, M.K.A. and Talib, A.A., RSM approach for modelling and optimization of designing parameters for inclined fins of the solar air heater. Renewable energy, 136, pp.48-68, 2019.

Promthaisong, P. and Eiamsa-ard, S., Fully developed periodic and thermal performance evaluation of a solar air heater channel with wavy-triangular ribs placed on an absorber plate. International Journal of Thermal Sciences, 140, pp.413-428, 2019.

Kumar, A. and Layek, A., Nusselt number and friction factor correlation of solar air heater having twisted-rib roughness on absorber plate. Renewable energy, 130, pp.687-699, 2019.

Singh, S., Dhruw, L. and Chander, S., Experimental investigation of a double pass converging finned wire mesh packed bed solar air heater. Journal of Energy Storage, 21, pp.713-723, 2019.

M.T. Baissi, A. Brima, K. Aoues, R. Khanniche, N. Moummi, Thermal behavior in a solar air heater channel roughened with delta-shaped vortex generators, Applied Thermal Engineering, Volume 165, 2020, 113563, ISSN 1359-4311,

Anbuchezhian, N., Velmurugan, T., Priyadharshini, G., Krishnamoorthy, R., Novel Design of Hybrid Steam Turbine Reflector Based Controller for Solar Power Plant, (2020) International Review of Mechanical Engineering (IREME), 14 (9), pp. 572-578.


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