DEPARTMENT OF MECHANICAL ENGINEERING

This systematic review examines the effectiveness and feasibility of heating and ventilation systems as critical interventions to mitigate substantial post-harvest maize losses in Nigeria, which currently range from 20% to 30%. The core challenge stems from Nigeria's humid, tropical climate, where high temperatures and relative humidity foster pest infestations, microbial growth, and the dangerous production of aflatoxins by Aspergillus species. The study finds that uncontrolled heat, particularly in structures like metal silos, encourages harmful moisture migration and spoilage , while controlled heating remains a potential solution for active grain drying. Ventilation is identified as the key defense mechanism, but its implementation is complicated: traditional natural airflow systems often fail in the humid southern regions, and powered aeration faces significant constraints due to high ambient humidity and an unreliable electricity supply.

The increasing demand for sustainable sanitation solutions underscores the need for innovative systems that conserve water, improve hygiene, and enhance user experience. This project has focused on the design and development of a Smart Urinal System—an automated facility that integrates a motion-switch with a microco-troller-based control unit to regulate flushing mechanisms. By eliminating manual operation, the system has reduced the risk of cross- contamination while optimizing flush cycles based on actual usage to conserve water. The methodology combines hardware design, circuit integration, and microcontroller programming to synchronize the switch inputs with actuator responses. Experimental results have shown that the system reduces water consumption by approximately 30–40% compared to conventional urinals while maintaining high hygiene standards. The study demonstrated that automation in sanitation not only promotes efficient water management but also offers a practical, user-friendly solution to modern hygiene challenges, particularly in regions where access to clean water remains limited

The problem of electricity in Nigeria has become some sort of a nationwide pandemic that has plagued the country for years and continues to do so. With seemingly no end in sight to the electricity crisis, food storage has become very expensive as individuals as well as producers need to pay a lot of money to run generators to power refrigerators. An alternative means to this would be a more than welcomed development. This project aims to reduce the cost encountered in refrigeration by using vapor absorption refrigeration which is powered by solar energy. The vapor absorption refrigerator uses water as its refrigerant, and zeolite is used as the absorbent. The compression system is a network of systems consisting of an absorber and a generator; aimed at compressing liquid refrigerant-absorbent mixture which requires less work to compress than vapor. The temperature of the evaporator, generator and condenser were measured and recorded periodically. The performance of the system is evaluated as the ratio of heat removed from the refrigerated space to the heat added to the system at the generator. The refrigerator proved quite functional, achieving a COP of 0.66. This validates the functionality of the system but it was observed that it took 3 hours of heating to produce a 9°c drop (from 34.2°c to 25.2°c) in evaporator temperature. After 5 hours of heating, there was a 15°c drop (from 34.2°c to 19.2°c) in evaporator temperature. However, the atmospheric temperature was 27°c which means the cooling achieved was not appreciable. The system used in this project suffered from a lot of leakages and heat loss which directly affected the performance of the system. We recommend that further studies on techniques which would prevent heat loss and meticulous fabrication process to prevent leakages allow. Significant reduction in heat loss would greatly improve the performance of the waste solar powered VARS thereby making it more viable and suitable for domestic and commercial usage

Measuring the volume of liquid stored in tanks is a routine but critical task in engineering applications, yet many commonly used methods still rely on direct contact and manual observation. Devices such as float gauges, sight glasses, and dipsticks are often affected by mechanical wear, environmental conditions, and human error, which reduces their reliability over time. In situations involving hazardous or enclosed liquids, these limitations become even more significant. This project addresses these issues through the development of a digital ultrasonic volumetric gauge that enables accurate, non-contact measurement of liquid volume. The primary aim of this work was to design and implement a system that determines liquid volume by measuring the liquid level and converting it into volumetric data using digital processing techniques. An ultrasonic sensor was employed to transmit and receive sound pulses, allowing the distance to the liquid surface to be calculated using the time-of-flight method. A microcontroller processed this distance data, applied calibration and volume conversion algorithms based on the tank’s geometry, and presented the results through a digital display and a web-based interface.

Nigeria’s energy security is heavily reliant on natural gas, a strategy hampered by supply unpredictability and growing global decarbonisation requirements. To address frequent outages caused by gas supply constraints and CO₂ emissions of 350-400 kg/MWh, a strategic pivot is necessary. This study proposes a transformative approach to addressing these dual challenges by retrofitting the Afam VI Natural Gas Combined Cycle (NGCC) power plant into an innovative Integrated Gasification Combined Cycle (IGCC) system. The study looks into the techno environmental feasibility of repurposing existing infrastructure to use domestic coal and biomass blends, hence increasing fuel flexibility and lowering the plant’s carbon footprint. This work applies a rigorous simulation-based technique using EBSILON® Professional. A validated baseline model of the present Afam VI plant, which operates at 49.88% efficiency at base load, was created. This model was later updated to incorporate a gasification unit, air separation unit, syngas clean-up techniques and pre-combustion carbon capture. Necessary modifications were also made to the topping and bottoming cycle of the thermal block for syngas combustion. Thermal analysis was carried out to assess system performance under both design and off-design scenarios. The results shows that the IGCC retrofit model reduces the net plant emission of the natural gas baseline model from about 300kg/MWh to about 50kg/MWh, indicating an 85.7% reduction in CO2 emission with a potential for carbon neutrality using biomass as feedstock. However, this comes off on the back of a trade off with the thermal performance of the plant. The retrofit model was found to have an energy efficiency penalty of about 4% points with respect to the natural gas baseline.

This study conducted a comprehensive hydrodynamic analysis and environmental adaptation of a trimaran model specifically designed for Nigerian coastal and inland waters. Employing Computational Fluid Dynamics (CFD) simulations, this research analyzed resistance, stability, maneuvering, and wave-making resistance. The CFD simulations, performed using the k-ω Shear Stress Transport (SST) turbulence model, captured critical hydrodynamic behaviour, including flow separation and wake interactions, with grid resolutions optimized through a grid independence study. Results showed that the refined grid achieved a stable resistance prediction at 125.4N, maintaining a y-plus range of 20 to 90 for accurate boundary layer modelling. There was a non-linear increase in resistance, reaching 450kN at 25 knots, and a metacentric height of 2.8m at a 10-degree heel angle, ensuring stability. Maneuvering analyses indicate a turning radius of 350m at a 25-degree rudder angle, demonstrating the trimaran's agility in confined waterways. Environmental adaptation showed a 20% increase in resistance under rough sea conditions, emphasizing the need for design optimizations. These findings highlight the trimaran's suitability for the challenging maritime conditions of Nigeria, balancing efficiency, stability, maneuverability, performance, safety, and adaptability while offering insights to optimizing future trimaran designs under similar environmental constraints. These findings also provide a framework for future designs that address local environmental challenges while maximizing operational efficiency. Nonetheless, optimizing side hull configurations to enhance wave cancellation effects and reducing wetted surface area to improve drag performance is recommended

The development of a prototype hovercraft represents a comprehensive effort to design, fabricate, and test a versatile transportation solution capable of traversing water, land, and marshy terrain. This final year project, carried out by the author to fulfill the requirements for the award of the degree of Bachelor of Mechanical Engineering, aimed to address the challenges of stability, maneuverability, and energy efficiency inherent in hovercraft technology while exploring opportunities for innovation and optimization. The prototype hovercraft was designed with a focus on achieving reliable performance, efficient propulsion, and a durable skirt system to maintain the air cushion necessary for lift. Through iterative design iterations, material selection, and fabrication processes, a small-scale hovercraft prototype was constructed, integrating advanced battery technology, a lightweight aluminum structure, and an optimized skirt design. Extensive testing and evaluation were conducted to assess the craft's capabilities across various operating conditions, including waterborne navigation, maneuvering on land, and stability in challenging environments. The successful testing of the prototype demonstrated its potential for applications in search and rescue, transportation, and environmental monitoring. However, limitations such as limited battery life and skirt design inefficiencies were identified, suggesting areas for further research and optimization. Overall, the project represents a significant step towards advancing hovercraft technology and its practical applications in addressing transportation challenges across diverse terrains.

The cleaning of living and work spaces are a fundamental human activity. Cleaning must be done for safety and human health. The process of cleaning can be cumbersome, tasking on the human muscle and time consuming when done in the traditional way of using brooms, brushes and similar tools. Modern living and work requirements demands that cleaning must be done fast and more efficiently. This need therefore demands that the cleaning of living and work spaces has to be mechanized to take away the burden from human muscles, improve efficiency, save time and cost. One way of achieving this is through the use of Vacuum Cleaners. A literature review during the course of this project work revealed that virtually all available Vacuum Cleaners listed and reviewed online as well as those found in shops here in Nigeria are highly technologically sophisticated and unaffordable for homes and small scale firms. The need therefore arises for the production of a locally affordable Vacuum Cleaner made from readily available local materials. The literature review and search identified a simple handheld Vacuum Cleaner that can be modified and adapted through a redesign to use locally available materials for its production. Several concept designs were proposed and the most acceptable in terms of simplicity, availability of local materials and affordability was chosen. The components for the chosen design were redesigned one by one with the idea of local production in mind. These includes the intake Wand and its dust agitator, the housing, the motor and its mounting within the housing, the air stream expansion section of the housing, the dust bag and its attachment to the housing and finally air flow exhaust area. After the design of these components the material needed for their fabrication were procured and the components fabricated. These fabricated components were then assembled to produce the portable Vacuum Cleaner complete with a shoulder hanging belt. The assembled unit was then tested in the 500 level classroom. The performance of the Vacuum Cleaner was found to be really effective in dust pickup through the dust agitator at the end of the end of the wand that is always pressed against the floor as it is pushed back and forth during the cleaning process. No dust particle size in the classroom was left on the floor during the testing. It is worthy of note that there was a small amount of very very fine particles of dust noticed in the effluent exhaust air. The posibble reasons suggested for this unwanted occurrence by our project group were listed as 1. A larger than required dust bag particle size retention holes that allowed these very fine dust particles to escape with the exhaust air. and or 2. Insufficient expansion of the exhaust air to reduce its speed to allow these very fine particles to deposit in the air stream expansion zone of the Vacuum Cleaner housing. For the fact that the fabricated Vacuum Cleaner was able to pick up virtually all particles on the floor, this project is therefore considered a great success. It is hoped that improvements to this design would continue to be carried out in future project work until it reaches the perfection in both aesthetics and performance for commercialization.

In Nigeria today and in the world at large, PET bottle waste has grown to become hazardous as it constitutes part of the non-biodegradable waste. Hence, recycling becomes necessary to curb its menace. This project work is centered on designing and fabricating a PET bottle crushing machine from locally sourced materials for both home and industrial use in an attempt to proffer solution to the PET waste problem in Nigeria. Preliminary tests and mechanical factors were extensively evaluated on the conceptual designs to ensure that the design that most suits the purpose was selected and detail design was carried out. Experiment to determine the power required to overcome the shear resistance of the PET bottles was carried out and it was discovered that 10hp at 450N was the power required. Finite element analysis was also performed on the cutting blade to inspect the materials response to stresses and the corresponding deformation. Furthermore, a design study was carried out in order to ascertain the minimum and maximum loads that can be handled. Tests carried out on the machine showed its efficiency to be 82.2% which is only 6% less than the efficiency of foreign counterparts.

A drone is defined as any airborne vehicle that receives remote instructions from a controller or relies on software for autonomous flight. Drones, also known as unmanned aerial vehicles (UAVs), perform tasks ranging from routine to highly hazardous. Initially designed for military and aerospace purposes, drones have gained widespread acceptance due to their heightened safety and efficiency benefits. Operating without an onboard pilot, drones eliminate the risk to human life in combat zones and can sustain flight without the need for rest as long as there is fuel available.Presently, advanced drones find applications across a diverse spectrum, including delivery services, law enforcement, surveillance of flood-prone areas, and numerous others highlighted in this report. The technology outlined in this report caters to various fields falling under the umbrella of Mechatronics, encompassing mechanical, electrical, and digital components. This project focuses on coming up with and developing a general-purpose drone that can be modified to serve a particular purpose