Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : thermal performance

Effect of Wavy Fins on Thermal Performance of Double Pass Solar Air Heater

Jalal M. Jalil; Rasha F. Nothim; Mustafa M. Hameed

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1362-1368
DOI: 10.30684/etj.v39i9.1775

In this paper, experimental study on double pass solar air heater with wavy fins absorber has been investigated. The fins attached to the upper and lower surfaces of the absorber. Two wavy fins arrangement (3 and 7 fins) have been investigated with plan absorber by changing solar radiation intensity (500, 600, 700 and 800 W/m2), air mass flow rate form 0.008575 kg/s to 0.0214375 kg/s. The results of wavy finned absorbers are compared with plane and the improving in thermal efficiency reached 80% and 84% in 3 and 7 wavy fins absorbers respectively.

Experimental Investigation of Thermosyphon Thermal Performance Using Different Filling Ratio

Talib Z. Farge; Samar J. Ismael; Rawad M.Thyab

Engineering and Technology Journal, 2021, Volume 39, Issue 1A, Pages 34-44
DOI: 10.30684/etj.v39i1A.1639

The present work investigated the thermal performance of thermosyphon by using distilled water as a working fluid at different filling ratios (50%, 60%, and 70 %). The thermosyphon was manufactured from a copper tube with outer and inner diameters (26 and 24) mm, respectively. The thermosyphon was tested experimentally at different input power (100, 200 and 300) Watt. The operating temperature of the oil was chosen below 85°C. Experimental results revealed that the filling ratio of 60% exhibited the best heat dissipation at the highest operating temperature. While the low operating temperature and 50 % filling ratio show better heat dissipation. Further, it was found that the thermal resistance of the thermosyphon was obviously decreased with increasing the input power. The percentage decrease in the thermal resistance of the thermosyphon at a filling ratio of 0.6 was 14.6 % compared with that filling ratio of 0.5 at an input power of 300 W.

Analysis of Thermal and Insulation Performance of Double Glazed Window Doped With Paraffin Wax

Jalal M. Jalil; Salih M. Salih

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 383-393
DOI: 10.30684/etj.v38i3A.448

In this paper, a numerical investigation has been performed to study the effect of varying the thermal properties of the paraffin wax on the performance of a double glazed window doped with it during the summer climate of Baghdad (33.3 °N, 44.4 °E). Using FORTRAN (f 90) constructed computer program, finite difference combined with the enthalpy method was utilized to deal with the conduction with phase change problems within the wax. Results obtained show that increasing the density, latent heat, and thickness of the paraffin wax PCM) would increase the temperature-time lag and reduce the temperature decrement factor of the double glazed window, and as a result, improve comparatively the performance of the unit. In contrast, changing the specific heat capacity of the paraffin wax is not a productive (inefficient) technique to develop the performance of the unit. Besides, the recommended thickness of the window (thickness of the PCM) under the ambient condition of Baghdad should be 20 mm or higher.