Browsing by Author "Adegun, Isaac Kayode"

Now showing 1 - 3 of 3
  • Item
    Numerical Investigation of Heat Transfer in Straight Pipe of Elliptic Cross-Section Rotating in Orthogonal Mode
    (Published Faculty of Engineering and Technology, University of Ilorin, 2026) Popoola, Olalekan Tajudeen; Lasode, Olumuyiwa Ajani; Adegun, Isaac Kayode; Rabiu, Abdulakarim Baba
    Efficient heat removal in rotating cooling channels remains a critical challenge in thermal systems such as blades of gas turbine and rotating heat exchangers, where complex rotational forces significantly influence flow and temperature distributions. However, the combined effects of pipe eccentricity and orthogonal rotation on turbulent heat transfer in noncircular ducts are not yet fully quantified. This study numerically investigates the heat transfer characteristics of fluid flow in a straight pipe with an elliptical cross-section that rotates in an orthogonal mode. The objectives are to evaluate the influence of eccentricity, Rossby number, and Prandtl number on convective heat transfer. A three-dimensional computational fluid dynamics (CFD) model which is based on the finite volume method was developed using ANSYS Fluent. Simulations were conducted at a Reynolds number of 17,000 with a constant wall heat flux for three eccentricities (0.433, 0.866, and 0.916) and Prandtl numbers ranging from 0.73 to 7. Mesh independence was achieved at approximately 1.07 × 10⁶ computational nodes. The results showed that the Nusselt number increased with both Rossby and Prandtl numbers, reaching a maximum value of approximately 340 at Pr = 7 and Ro = 0.1. The pipe with eccentricity 0.916 exhibited the highest heat transfer performance. The findings provide practical design guidance for cooling channels in rotating machinery such as gas turbines, heat exchangers, and rotating electrical systems.
  • Item
    Performance Evaluation of Aluminum-in-Pot Evaporative Cooler
    (School of Science and Engineering, São Paulo State University (UNESP), 2025) Olalekan Tajudeen POPOOLA; Issa, Haruna Ayotunde; Adegun, Isaac Kayode; Omoniyi, Peter Olorunleke; Ibrahim, Hassan Kobe
    Cooling applications by refrigeration and air-conditioning require electricity as a source of energy not abundantly available in sub-Saharan African countries. Post-harvest losses of vegetables are caused by poor storage facilities, poor transportation systems, and lack of processing facilities. The current study aimed to evaluate the performance of developed solar-powered Aluminium-in-pot evaporative coolers lined with clay and charcoal blends for the preservation of tomatoes. The evaporative cooler consisted of Aluminium pots inserted into an earthenware mould pot, and the space between the two pots filled with lining media of clay, charcoal, and blends of the two in different ratios. The dry bulb temperature of the ambient air, inner temperatures of the cooling chambers, and relative Humidity were measured using fresh tomatoes as a load for the coolers. The temperature variations of the coolers were recorded for fifteen consecutive days. It was found that the inner temperatures for the five evaporative coolers were significantly different from the dry bulb temperature of the ambient. The temperature of sample E had the lowest temperature range of 19.65 C to 23.65 C for the no-load test, 21.15 C to 25.29 C for the load–load-test (better boy), and 21.1 to 23.25 C for the load test (Plum). The daily temperature in the coolers dropped significantly to a range of between 3.4 C to 10.46 C with a corresponding daily RH range of 30.93% to 39%. The variations in the efficiency of Sample E were found to be averagely 84% at no load, 72% when loaded with Better Boy and 77% when loaded with Plum tomatoes. The aluminium in pot evaporative cooler could be used for a short-term preservation of tomatoes in remote areas where electricity is not available.
  • Item
    Proximate and Mineral Analysis of Evaporative Cooled Tomatoes
    (Faculty of Technology, Ladoke Akintola University of Technology, 2026) Olalekan Tajudeen POPOOLA; Issa, Haruna Ayotunde; Adegun, Isaac Kayode; Ibrahim, Hassan Kobe
    Postharvest losses of tomatoes remain a major challenge in sub-Saharan Africa due to erratic power supply and inadequate storage systems. This study evaluated the effects of aluminium-in-pot evaporative cooling systems on the proximate composition, mineral content, and physiological weight loss of two tomato cultivars (UTC and Plum). The tomatoes were stored in five different Aluminium-in-pot evaporative (A, B, C, D and E) coolers and under ambient conditions (control). The proximate analysis was done using Association of Official Analytical Chemists (AOAC) methods, while mineral contents, lycopene, and vitamin C were determined using an atomic absorption spectrometer and titrimetric methods, respectively. Results showed that weight loss in the evaporative cooling system ranged from 2% to 9% as compared to the weight loss of the control case, which varied from 3.7% to 25%. The shelf life of tomatoes in evaporative cooler E was extended to 15 days, while for the control case, it lasted only 4 to 5 days. Additionally, evaporative cooling significantly reduced weight loss and rate of decay while improving retention of moisture, vitamin C, lycopene, and essential minerals relative to ambient. These findings demonstrate the effectiveness of evaporative cooling as a low-cost, sustainable technology for extending tomato shelf life and preserving nutritional quality, with potential applications in post-harvest storage system design.