Evaluation of Aerodynamics and Pressure Distribution around a Moving Vehicle
Designing a Bearing Monitoring and Control System for Improvement of the Bearing Life on a Horizontal Milling Machine
A Systematic Review of Design of Experiments for Arc Welding Defect Development in NDT Training for Zimbabwe
A Comparative Review of Pneumatic Cylinders and Magnetic Actuators in the Design of Automatic Pouch Cell Folding Machines: Implications for Zimbabwe's Battery Manufacturing Industry
Development and Optimization of a Herbal Tablet Manufacturing Machine for Zumbani Traditional Medicine in Zimbabwe: A Case Study
Design of Oil-Ammonia Separator for Refrigeration Systems
A Review on Mechanical and Tribological Characteristics of Hybrid Composites
Progressive Development of Various Production and Refining Process of Biodiesel
Design and Experimental Investigation of a Natural Draft Improved Biomass Cookstove
Optimization of Wire-ED Turning Process Parameters by Taguchi-Grey Relational Analysis
Evaluation Of Mechanical Behavior Of Al-Alloy/SiC Metal Matrix Composites With Respect To Their Constituents Using Taguchi Techniques
Multistage Extractive Desulfurization of Liquid Fuel by Ionic Liquids
Isomorphism Identification of Compound Kinematic Chain and Their Mechanism
Development of Electroplating Setup for Plating Abs Plastics
A Comprehensive Review of Biodiesel Application in IDI Engines with Property Improving Additives
Electric vehicles are gaining market dominance due to their sustainability; however, they still need to acquire superior performance with long driving range, high stability, and low operating costs. This study analyzes air pressure, velocity, and force distribution in a moving car mostly at high speeds to tap into the potential energy of moving air to charge the vehicle battery. SOLIDWORKS modeling software is used to design a 3D CAD car model. Computational Fluid Dynamics (CFD) flow simulation is further used to validate the theory of stagnation and wake pressure in the front and back of the car, respectively. A BMW 3 Series model shape is considered as base model, and it is analyzed to find the actual pressure difference trend as the car moves. The same boundary conditions are used for the entire model at a vehicle velocity range of 0 - 35 m/s. The front region of the vehicle is found to experience the highest air pressure and velocity change, translating to a significant loss of energy into other energy forms. Pressure drag is found to be a function of the pressure difference between the front and the back faces of the moving vehicle. At 5 m/s, the pressure difference was observed to be 25 Pa, whilst at 40 m/s, the pressure difference was 800 Pa, which is a considerable rise translating to an increased drag force. Simulation results were found to be coherent with the mathematical model results, thereby validating this work. This calls for further design improvement in the vehicle shape to reduce the pressure difference, hence improving the efficiency and range of the vehicle.
Bearings are critical components in horizontal conventional milling machines, ensuring smooth operation, precision, and longevity of the machine. This study investigates the effects of temperature, load, and vibration on the bearing life of a horizontal conventional milling machine at the Harare Institute of Technology (HIT) workshop. The study involves experimental analysis to measure these parameters under varying operating conditions, with a focus on addressing frequent machine breakdowns. The results provide insights into the relationship between these parameters and bearing life, offering recommendations for optimizing bearing performance and machine efficiency. The findings are supported by data, graphs, and diagrams, with references to relevant literature.
This work critically examines existing literature on the application of Design of Experiments (DoE) methodologies in the development, characterization, and utilization of arc welding defects for Non-Destructive Testing (NDT) training programs, with a specific focus on addressing challenges and opportunities in Zimbabwe. It recognizes the critical need for skilled NDT personnel capable of accurately identifying and characterizing weld imperfections, emphasizing the limitations of traditional training approaches due to the scarcity of standardized, representative defect samples. The paper explores past methods for creating standard defects such as trial-and-error welding, machining artificial flaws, and using defective welds from service and highlights the benefits of a DoE-driven approach, including reproducible defect creation and optimized welding parameters for specific defect types. It also analyzes the effectiveness of various NDT methods, e.g., ultrasonic testing, radiographic testing, and magnetic particle inspection, in characterizing and quantifying defects while examining the challenges of simulating real-world conditions in laboratory settings. Drawing upon insights from over 20 authors, the work provides a comparative analysis of current practices, identifies key areas for improvement, and offers evidence-based recommendations for aligning training programs with industry needs and international standards, ultimately aiming to inform workforce development and enhance the reliability of welding processes in Zimbabwe's expanding industrial sector.
The global shift toward renewable energy and electric vehicles (EVs) has increased the demand for Lithium-Ion batteries, particularly pouch cells. Automatic pouch cell folding machines are essential for ensuring the precision and efficiency of battery manufacturing. In Zimbabwe, where the mining of Lithium, a key raw material for batteries, is expanding, the development of a local battery manufacturing industry presents a significant economic opportunity. This paper compares two key actuation technologies, pneumatic cylinders and magnetic actuators, in the context of designing automatic pouch cell folding machines. The analysis considers factors such as performance, energy efficiency, precision, maintenance, and cost, with a focus on their applicability to Zimbabwe's Industrial and economic landscape. The paper concludes with recommendations for adopting the most suitable technology to support Zimbabwe's emerging battery manufacturing sector.
Traditional medicine plays a crucial role in Zimbabwe's healthcare system, with herbal remedies, particularly those derived from Zumbani (Lippia javanica), being widely utilized. However, the inconsistent quality and lack of standardized manufacturing processes associated with traditional methods pose significant challenges to patient safety and the effective delivery of these remedies. To address these limitations, this study presents a case study focused on the development and optimization of a specialized herbal tablet manufacturing machine designed for Zumbani. The study details the design and construction of a prototype machine utilizing locally available resources, emphasizing efficiency, precision, scalability, and compliance with regulatory standards. A key aspect of the study involves the optimization of the cam profile, a critical tablet compression machine part, to enhance tablet quality attributes such as hardness and disintegration time. Three cam profile designs are explored, such as Variable Profile Cam, Sequential Cam Profile, and Pear Shaped Cam Profile. Each cam profile focuses on adjusting the upper and lower punches that control the tablet compression process. A series of performance tests were conducted to evaluate the machine's efficiency and energy consumption, with rigorous testing to ensure compliance with local regulatory standards and certification requirements. The results demonstrate significant improvements in production capacity, tablet quality, and adherence to pharmacopoeial standards compared to traditional methods.
