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Research Article
Design, Realisation and Performance Evaluation of an Optimised Drying Oven for Maize Post-Harvest Processing
Noutegomo Boris*
Issue:
Volume 14, Issue 5, October 2026
Pages:
88-96
Received:
15 April 2026
Accepted:
13 June 2026
Published:
21 October 2026
DOI:
10.11648/j.ijmea.20261405.11
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Abstract: Post-harvest losses in maize production remain a major challenge in many developing countries due to inefficient traditional drying methods such as sun drying, which often result in microbial contamination, reduced grain quality, and economic losses associated with high residual moisture content. This study presents the design, realization, and performance evaluation of an optimized drying oven for maize post-harvest processing. The system was designed using functional and structural engineering approaches with modelling carried out in SolidWorks, while airflow and heat distribution within the drying chamber were analysed using computational fluid dynamics (CFD) simulations. The developed prototype features an insulated drying chamber, dual-fan air circulation, and sensor-based temperature control to enhance thermal uniformity and energy efficiency. Experimental drying tests were conducted on 7.5 kg of maize at 50°C, 55°C, and 60°C, with temperature and moisture variations monitored using thermocouples and moisture analysers. Results showed that moisture ratio decreased steadily with drying time, with drying duration reducing from 300 min at 50°C to 240 min at 60°C. The drying process occurred mainly in the falling-rate period, indicating moisture diffusion as the dominant mechanism. Energy efficiency increased from 75.57% to 80.96%, and final moisture content reached the safe storage range of 13-14%. The results demonstrate that the developed drying oven provides an efficient, reliable, and scalable solution for maize drying, contributing to improved post-harvest handling and reduced grain losses.
Abstract: Post-harvest losses in maize production remain a major challenge in many developing countries due to inefficient traditional drying methods such as sun drying, which often result in microbial contamination, reduced grain quality, and economic losses associated with high residual moisture content. This study presents the design, realization, and per...
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Research Article
Experimental Exploration into Al 7075-T651 Machinability, Surface Quality, and MRR Using Avocado Cutting Fluid via Grey Optimization
Abera Ayza Anebo*,
Temesgen Hailegirogis,
Workineh Gebeyehu,
Biniyam Bekele Toma
Issue:
Volume 14, Issue 5, October 2026
Pages:
97-113
Received:
22 September 2026
Accepted:
4 October 2026
Published:
21 October 2026
DOI:
10.11648/j.ijmea.20261405.12
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Abstract: This research aims to identify the optimal machining parameters for turning Aluminium Alloy 075-T651 using a tungsten carbide insert cutting tool and a flood coolant system, applying the Grey-based Taguchi method. Aluminium Alloy 075-T651 is commonly utilized in the automotive, marine, machine tools, and aerospace industries due to its excellent weight-to-strength ratio. A key focus of the study are the surface roughness and material removal rate, which is critical in machining. The research explores how various turning parameters affect surface roughness and material removal rate with investigates the role of coolant in these operations. Heat generated during machining can adversely affect tool life, workpiece dimensions, and surface quality. To address these challenges, an environmentally friendly, biodegradable, and non-toxic avocado oil-based cutting fluid was employed. An orthogonal array from the Taguchi method guided the experiments, with surface roughness and material removal rate measured as a response. Minitab software facilitated the statistical analysis of process parameters. Key performance metrics included material removal rate, and surface roughness, influenced by cutting speed, feed rate, depth of cut, and avocado oil proportion. So, an avocado oil (9%), depth of cut (1.0 mm), cutting speed (1000 rpm), and feed rate (85 mm/min) are an optimized parameter.
Abstract: This research aims to identify the optimal machining parameters for turning Aluminium Alloy 075-T651 using a tungsten carbide insert cutting tool and a flood coolant system, applying the Grey-based Taguchi method. Aluminium Alloy 075-T651 is commonly utilized in the automotive, marine, machine tools, and aerospace industries due to its excellent we...
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Research Article
Numerical Investigation of the Performance of a Vortex Tube-Based Vehicle Cabin Cooling System
Sintayehu Assefa Endaylalu*,
Genet Tesfaye Degene
Issue:
Volume 14, Issue 5, October 2026
Pages:
114-126
Received:
3 September 2026
Accepted:
14 September 2026
Published:
21 October 2026
DOI:
10.11648/j.ijmea.20261405.13
Downloads:
Views:
Abstract: The vortex tube is a fundamental device that produces two different temperatures and low-pressure flows from a single compressed, high-pressure, high-temperature flow. It is a stationary device used to separate the compressed air into cold and hot streams. Its function is based on the concept of air vortex stream movement. Conventional automotive air conditioning systems use refrigerants and vapor compression cycles, which contribute to high energy use and greenhouse emissions. Therefore, this work focused on a numerical study of the performance of a vortex tube for vehicle cabin cooling system applications by considering the inlet nozzles, cold-end diameter, and hot-tube length. The study was conducted with various inlet pressures from 4 to 7 bar, cold mass fractions from 0.3 to 0.5, and hot-tube parameters using a tube length of 106mm as a baseline, and also length-to-diameter ratios of 10, 15, and 20. The results show that increasing inlet pressure increases cooling capacity but reduces the coefficient of performance, while a higher cold mass fraction improves cooling load with moderate efficiency gains. The hot-tube length optimization showed that longer tubes slightly increase cooling capacity, but do not significantly improve the coefficient of performance, which indicates diminishing returns beyond a length-to-diameter ratio of approximately 10 to 15. Similarly, the cold-end diameter optimizations indicated that a strong influence was observed with the best configuration of hot tube length 115mm per unit tube diameter 1.4mm and 8 mm cold-end diameter at 4bar inlet pressure and cold mass fraction of 0.5 achieved a cooling load of 119W at COP 0.232. Finally, this study concludes that hot tube length offers incremental gains, while cold-end geometry is the key driver for improving vortex tube performance in vehicle cooling systems.
Abstract: The vortex tube is a fundamental device that produces two different temperatures and low-pressure flows from a single compressed, high-pressure, high-temperature flow. It is a stationary device used to separate the compressed air into cold and hot streams. Its function is based on the concept of air vortex stream movement. Conventional automotive a...
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