Experimental investigation on heat transfer and friction factor for an inclined spherical ball roughened solar air heater

Experimental investigation on heat transfer and friction factor for an inclined spherical ball roughened solar air heater

Ramesh MurmuP. Kumar H. N. Singh 

Research Scholar, Mechanical Engineering Department, NIT Jamshedpur Jharkhand 831014, India

Corresponding Author Email: 
murmunitjsr@gmail.com
Page: 
7-36
|
DOI: 
https://doi.org/10.3166/I2M.17.7-36
Received: 
|
Accepted: 
|
Published: 
31 March 2018
| Citation

OPEN ACCESS

Abstract: 

The purpose of present investigation is to determine the results of heat transfer and frictional losses for an inclined spherical ball roughened solar air heater. Experimentation was conducted under actual outdoor condition at the test rig designed and fabricated at the terrace of the Mechanical Engineering Department, NIT Jamshedpur, India. To show the effect of ever-changing environmental variables like solar radiation, wind velocity, ambient temperature, etc, on the heat transfer results, the readings were noted for every 15 minutes in the experimental hours 10:00 to 15:00 hours. The present paper deals with the experimental results drafted in the form of rise in Nusselt number (Nu) and friction factor (f) for spherical ball roughened solar air heater (SAH) over those of smooth ones. Flow and roughness geometrical parameters have been varied as relative roughness pitch (p/e) 9-18, relative roughness height (e/Dh) 0.024-0.040, ball’s height to diameter ratio (e/db) 0.5-2, angle of attack (α) 35˚-75˚ and Reynolds no (Re) 2500-18500. Parametric analysis has also been made and the effects of these parameters on Nu and f characteristics have been shown. This article reveals that maximum augmentation in ‘Nu’ & ‘f’ for varying ‘p/e’, ‘e/Dh& ‘e/db’ and ‘α’ was respectively found to be of the order of 2.1 to 3.54 times, 1.87 to 3.21 times and 2.89 to 3.27 & 1.74 to 3.56 times for ‘Nu’ and 0.84 to 1.79 times, 1.46 to 1.91 times, 1.67 to 2.34 times & 1.21 to 2.67 times for ‘f’ in compared to non-roughened duct. The optimum roughness parameters found under present investigation is p/e = 15, e/Dh = 0.036, e/db = 1 and α = 55˚. The findings of this research may serve as a criteria to determine thermal and thermohydraulic performance of such roughened solar air heaters and to understand the magnitude of useful heat gain choosing such roughness geometry.

Keywords: 

solar energy, spherical ball, relative roughness pitch, relative roughness height, Height to diameter ratio, angle of attack

1. Introduction
2. Investigation methodology
3. Heat transfer and friction characteristics
4. Conclusions
Nomenclature
  References

Ahn S. W. (2001). The effects of roughness types on friction factors and heat transfer in roughened rectangular duct. International Communications in Heat and Mass Transfer, Vol. 28, No. 7, pp. 933-942.

Bhagoria J. L., Saini J. S., Solanki S. C. (2002). Heat transfer coefficient and friction factor correlation for the transitional flow regime in rib-roughened rectangular duct. Renewable Energy, Vol. 25, No. 3, pp. 341-369. https://doi.org/10.1016/S0960-1481(01)00057-X

Chandra P. R., Alexander C. R., Han J. C. (2003). Heat transfer and friction behaviors in rectangular channel with varying number of ribbed walls. International Journal of Heat Mass Transfer, Vol. 46, No. 3, pp. 481-495. https://doi.org/10.1016/S0017-9310(02)00297-1

Chang S. W., Liou T. M., Chiang K. F., Hong G. F. (2008). Heat transfer and pressure drop in rectangular channel with compound roughness of V-shaped ribs and deepened scales. International Journal of Heat Mass Transfer, Vol. 51, No. 3-4, pp. 457-468. https://doi.org/10.1016/j.ijheatmasstransfer.2007.05.010

Gupta D., Solanki S. C., Saini J. S. (1993). Heat and fluid flow in rectangular solar air heater ducts having transverse rib roughness on absorber plate. Solar Energy, Vol. 51, pp. 31-37. https://doi.org/10.1016/0038-092X(93)90039-Q

Gupta D., Solanki S. C., Saini J. S. (1997). Thermohydraulic performance of solar air heaters with roughened absorber plates. Solar Energy, Vol. 61, No. 1, pp. 33–42. https://doi.org/10.1016/S0038-092X(97)00005-4

Hale S. J. B. (1986). Methods of testing to determine the thermal performance of solar collectors. American Society of Heating, Refrigerating and Air-conditioning Engineers.

Han, J. C., Park, J. S. and Lei, C. K., 1985, Heat transfer enhancement in channel with turbulence promoters. Journal Engineering for Gas Turbine and Power, Vol. 107, No. 3, pp. 628-635. https://doi.org/10.1115/1.3239782

Jaurer A. R., Saini J. S., Gandhi B. K. (2006). Heat transfer coefficient and friction characteristics of rectangular solar air heater duct using rib-grooved artificial roughness. Solar Energy, Vol. 80, No. 8, pp. 895-907. https://doi.org/10.1016/j.solener.2005.08.006

Kline S. J., Mcclintock F. A. (1953). Describing uncertainties in single sample experiments. Mechanical Engineering, Vol. 75, pp. 3–8.

Kumar V., Prasad L. (2017). Experimental investigation on heat transfer and fluid flow of air flowing under three sides concave dimple roughened duct. International Journal of Mechanical Engineering and Technology (IJMET), Vol. 8, No. 11, pp. 1083–1094.

Kumar V., Prasad L. (2017). Thermal performance investigation of one and three sides concave dimple roughened solar air heaters. International Journal of Mechanical Engineering and Technology (IJMET), Vol. 8, No. 12, pp. 31–45.

Lau S. C., McMillan R. D., Han J. C. (1991). Turbulent heat transfer and friction in a square channel with discrete rib tabulators. Heat Transfer, Vol. 113, No. 3, pp. 360-366. https://doi.org/10.1115/1.2927884

Mahmood G. I., Ligrani P. M., Chen K. (2003). Variable property and temperature ratio effects on Nusselts number in a rectangular channel with 45˚ angled rib turbulators. Journal of Heat Transfer, Vol. 125, No. 5, pp. 769-778. https://doi.org/10.1115/1.1589503

Momin A. M. E., Saini J. S., Solanki S. C. (2002). Heat transfer and friction in solar air heater duct with V-shaped rib roughness on absorber plate. International Journal of Heat and Mass Transfer, Vol. 45, No. 16, pp. 3383-3396. https://doi.org/10.1016/S0017-9310(02)00046-7

Muneer T., Asif M., Munawwar S. (2005). Sustainable production of solar electricity with particular reference to the Indian economy. Renewable and Sustainable Energy Reviews, Vol. 9, No. 5, pp. 444-473. https://doi.org/10.1016/j.rser.2004.03.004

Naphon P. (2008). Effect of corrugated plates in an in-phase arrangement on the heat transfer and flow developments. International Journal of Heat Mass Transfer, Vol. 51, No. 15-16, pp. 3963-3971. https://doi.org/10.1016/j.ijheatmasstransfer.2007.11.050

Pandey N. K., Bajpai V. K., Varun. (2016). Experimental investigation of heat transfer augmentation using multiple arcs with gap on absorber plate of solar air heater. Solar Energy, Vol. 134, pp. 314–326. https://doi.org/10.1016/j.solener.2016.05.007

Prasad B. N., Saini J. S. (1988). Effect of artificial roughness on heat transfer and friction factor in a solar air heater. Solar Energy, Vol. 41, No. 6, pp. 555–560. https://doi.org/10.1016/0038-092X(88)90058-8

Ridouane E. I. H., Campo A. (2007). Heat transfer and pressure drop characteristics of laminar air flows moving in a parallel-plate channel with transverse hemi-cylindrical cavities. International Journal of Heat and Mass Transfer, Vol. 50, No. 19-20, pp. 3913-3924. https://doi.org/10.1016/j.ijheatmasstransfer.2007.02.004

Saini R. P., Saini J. S. (1997). Heat transfer and friction factor correlations for artificially roughened ducts with expanded metal mesh as roughness element. International Journal of Heat and Mass Transfer, Vol. 40, No. 4, pp. 973-986. https://doi.org/10.1016/0017-9310(96)00019-1

Saini S. K., Saini R. P. (2008). Development of correlations for Nusselts number and friction factor for solar air heater with roughened duct having arc-shaped wire as artificial roughness. Solar Energy, Vol. 82, No. 12, pp. 1118-1130. https://doi.org/10.1016/j.solener.2008.05.010

Sethi M., Varun, Thakur, N. S. (2012). Correlations for solar air heater duct with dimpled shape roughness elements on absorber plate. Solar Energy, Vol. 86, No. 9, pp. 2852–2861. https://doi.org/10.1016/j.solener.2012.06.024

Skullong S., Promvonge P. (2014). Experimental Investigation on Turbulent Convection in Solar Air Heater Channel Fitted with Delta Winglet Vortex Generator. Chinese Journal of Chemical Engineering, Vol. 22, No. 1, pp. 1-10. https://doi.org/10.1016/S1004-9541(14)60030-6

Varun, Saini R. P., Singal S. K. (2008). Investigation on thermal performance of solar air heaters having roughness elements as a combination of inclined and transverse ribs on the absorber plate. Renewable Energy, Vol. 33, No. 6, pp. 1398-1405. https://doi.org/10.1016/j.renene.2007.07.013

Wongcharee K., Changcharoen W., Eiamsa-ard S. (2011). Numerical investigation of flow friction and heat transfer in a channel with various shaped ribs mounted on two opposite ribbed walls. International Journal of Chemical Reactor Engineering, Vol. 9, No. 1, pp. 1-21. https://doi.org/10.1515/1542-6580.2560