Experimental and numerical evaluation of a multi-pad evaporative cooler
| dc.contributor.author | Okafor, Victor Chijioke | |
| dc.date.accessioned | 2026-03-23T12:00:08Z | |
| dc.date.available | 2026-03-23T12:00:08Z | |
| dc.date.issued | 2021 | |
| dc.description | This is thesis is for the award of Doctor of Philosophy(PhD.) in Power and Machinery Engineering | |
| dc.description.abstract | An automated open circuit multi-pad wind tunnel controlled by Arduino microprocessor was constructed. The multi-pad test rig is made up of four identical chambers insulated from each other. Each chamber has three zones (air inlet, measurement and air outlet) and consists of 12V dc suction fans, 12V dc water pumps, and pressure, temperature/humidity sensors connected to a programmable circuit board (micro-controller) with a piece of software (integrated development environment, IDE) known as Arduino microprocessor which controls and automates the overall operation of the cooler system through its relay and receives signals from the sensors placed at the measurement zone of the wind tunnel. The inlet and exit temperatures, humidity and static pressure of the air passing through the wetted pad were measured, recorded and displayed on the liquid crystal display (LCD) and transferred to a microcomputer via a universal serial board (USB) cord. The experiment was conducted using the Randomized Complete Block (RCBD) layout. Four (4) cooling pad materials were used for the evaluation of the multi-pad evaporative cooler. The selected cooling pad materials are: (1) Imported rigid media (Celdek), (2) Jute fibre (3) Coconut fibre and (4) Pop sponge. Cooling pad saturation efficiency and static pressure drop across the wetted pad form the two major performance criteria while pad face air velocity (v), pad thickness (t) and water flow rate (w) formed the major treatments (ie factors VTW). Each of the three factors had five levels. For pad face air velocity (v): 0.5, 1.0, 1.5, 2.0 and 2.5m/s; For pad thickness (t): 50, 100, 150, 200 and 150mm and for water flow rate (w): 1.0, 1.25, 1.5, 1.75, and 2.0l/min. Results obtained show that saturation efficiency increases with increasing pad thickness and pad face air velocity for all the pad except for Celdek that showed a slight decrease in saturation efficiency with increasing pad face air velocity. The results of the tests conducted to evaluate the effects of the water flow rate on the saturation efficiency of pad materials indicated that the range of water flow rate chosen had little effect on the saturation efficiency. Saturation efficiency ranged from 51.3% to 80.7%; 56.3% to 83.9%; 54.7% to 80.6%; 46.8% to 71.9% for Celdek, ute fibre, Coconut fibre and Pop sponge respectively. While Pressure drop ranged from 2.3Pa to 63.2Pa; 11.1Pa to 150.5Pa; 8.3Pa to 130.6Pa and 5.5Pa to 104.7Pa for Celdek, Jute fibre, Coconut fibre and Pop sponge respectively. Central Composite Design in Design Expert 6.0. Statistical Software was used for the statistical analysis while online Tukey’s honestly significant difference (HSD) test was used for means separation. Model equations-based on Buckingham π - theorem using multiple regression analysis was developed. | |
| dc.identifier.citation | Okafor, V. C. (2021). Experimental and numerical evaluation of a multi-pad evaporative cooler [Unpublished Doctoral Thesis]. Federal University of Technology, Owerri, Nigeria | |
| dc.identifier.uri | https://repository.futo.edu.ng/handle/20.500.14562/2448 | |
| dc.language.iso | en | |
| dc.publisher | Federal University of Technology, Owerri | |
| dc.rights | Attribution-NonCommercial-ShareAlike 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-sa/4.0/ | |
| dc.subject | Saturation efficiency | |
| dc.subject | evaporative cooling | |
| dc.subject | cooling pads | |
| dc.subject | Department of Agricultural and Bioresources Engineering | |
| dc.subject | pressure drop | |
| dc.title | Experimental and numerical evaluation of a multi-pad evaporative cooler | |
| dc.type | Doctoral Thesis |