Semarak Journal of Thermal-Fluid Engineering

Design and Development of Small Milling Machine for Powder Metallurgy Application

Md.Nor Anuar Mohamad — 2024-12-18

The process of powder metallurgy milling, which reduces solid metal to fine particles to improve its properties, is the subject of this study. The objective is to determine the RPM and time relationship for efficient grinding and to fabricate a small milling machine for powder applications. Particle size, time, and homogeneity requirements are examined. The milling machine is designed in SolidWorks. Aluminium chips are used for test runs. Particle sizes are evaluated at different times using an optical microscope. The Arduino control system and a 12 V DC motor are used. Longer grinding times consistently result in smaller chips. Based on the result, the average of the 5.79 mm chip size measurements made before milling was determined. Following the milling process, the sizes were 0.75 mm at two hours, 0.51 mm at four hours, and 0.27 mm at six hours. The study shows that the efficiency and particle size distribution of powder metallurgy milling can be improved using a small machine with a fixed bar and different types of grinding media. For effective milling, it is crucial to maximize mill rotation, as shown by critical speed analysis. To sum up, the study effectively creates a small milling machine for use in powder metallurgy procedures.

Bioinspired of Natural Flyers: Flapping-Wing Micro-Aerial-Vehicle

Mohd Firdaus Abas — 2024-12-31

Nature creatures like birds and insects can fly during harsh weather with significantly diversified superficial structures on their bodies. The innovation of bioinspired designs through biomimicry has been implemented to improve modelling and simulation of real-life birds and insects to attain a better understanding of the wing's critical features, kinematic motion, and its aerodynamic behaviour, thus development a much realistic Flapping-Wing Micro-Aerial-Vehicle. This paper reviews a part of previous MAV research developments which are of significant novelty and contribution from small birds to big insects, within the transition Reynolds number regimes. Findings suggest that limited work has been done. Limited experimental research has been done compared to numerical research for the insect-like MAV due to replication difficulties of high flapping frequencies and complex miniature prototypes.

Analysis of Louvre Angles in Cross Ventilation Systems for Enhanced Airflow and Indoor Cooling

Muhammad Amirul Amir Roshezam — 2024-12-31

Cross ventilation is one of the most common strategies for enhancing indoor comfort and decreasing pollutants’ concentrations. It can also be used as an indirect cooling tool to lower cooling requirements for buildings. Nevertheless, inadequate distribution of airflow in buildings and incorrect orientation of the louvres result in localized thermal discomfort and inadequate ventilation. This paper looks at the airflow patterns of a SolidWorks designed ventilation system and examines the influence of various louvre positions and slat angles of 15° and 30° through numerical modeling. The simulations were performed using RNG k-ε and SST k-⍵ turbulence models with the wind inlet velocity of 0.3 m/s which is the average wind velocity in Malaysia. The findings indicate that a 15° slat angle provides the best airflow distribution because the small angle allows a smooth entrance of air and little turbulence. On the other hand, a 30° slat angle increases velocity and pressure at the inlet and leads to turbulence and issues for indoor climate. The SST k-⍵ model provided higher velocity predictions than the RNG k-ε model, suggesting that it is better for capturing the detailed flow characteristics. Therefore, this study was able to show the effects of louvre angles on airflow patterns and found the 15° slat angle to be the most effective for ventilation with low turbulence.

Optimizing Mushroom Cultivation: PV-Powered Environmental Control Systems

Muhammad Zariq Imran Abdul Manap — 2024-12-18

Solar Photovoltaic (PV) technology, which converts solar radiation into electrical energy, is increasingly used in agriculture to power farm appliances. However, maintaining optimal environmental conditions for crop cultivation remains challenging. This study addresses this issue by integrating PV technology with an environmental monitoring and control unit to create a self-sustainable greenhouse, enhancing crop breeders’ efficiency. The primary problem addressed is the difficulty in maintaining stable temperature and humidity levels in mushroom cultivation environments. The research aims to develop and simulate a PV-powered temperature control system for an oyster mushroom house, chosen due to its high market demand. Using Matlab/Simulink, a working model simulation was created to analyze the system’s performance in maintaining optimal temperature and humidity levels. The simulation, based on energy balance equations, connects a mushroom house subsystem to Simscape electrical components and a solar panel. Simulation results indicate that the system can maintain a stable temperature around 25.7℃ throughout the day, regardless of ambient temperature variations. In conclusion, the study successfully developed a solar-powered temperature control system for oyster mushroom cultivation, demonstrating its potential to enhance the efficiency and sustainability of agricultural practices.

Analysis on the Turbulence Flow on Propeller with Varying Blades Counts

Muhammad Haziq Haron — 2024-12-31

This paper aims at investigating the impact of changing the number of blades on the thrust force and efficiency at turbulent flows to improve the propeller design. The propeller performance is important in many applications, such as aviation and marine propulsion systems, where efficiency and thrust force are important. A CFD approach was used to study the flow field and thrust and torque characteristics of propellers with two, three, and four blades. These simulations were based on the velocity and pressure distributions, thrust force, and aerodynamic efficiency, all of which were maintained at optimal levels of operation. Quantitative analysis revealed a clear trend: greater numbers of blades increased the thrust force and efficiency of the system. In particular, the thrust force increased three times when comparing the blade numbers of two and three, changing from 0.3556 N to -1.2766 N. The same trend was observed for the thrust force, which increased from 1.4966 N for the three blades to 2.9818 N for the four blades. This shows that the addition of blades does increase efficiency, but the degree to which this increases efficiency decreases as the number of blades increases: an example of a nonlinear relationship. The thrust coefficient also increased with the number of blades, suggesting better aerodynamics. Additional information was obtained from the velocity and pressure contours. For the two-blade configuration, the flow separation resulted in high pressure around the rotation domain and low pressure in the static domain for the thrust force. The three- and four-blade designs showed that the flow was smoother, the flow separation was less pronounced, and the pressure differences were higher, which contributed to higher thrust and efficiency. The results of this research advance the understanding of propeller behavior in turbulent flow fields. This paper proposes a mathematical model that establishes the correlation between the blade count and aerodynamic performance, which will be useful for future propeller design in aviation, marine, and other forms of transport. More studies should be conducted to understand higher blade geometries and materials to enhance efficiency.