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Purpose The purpose of this paper is to examine geometrical design influence of various types of flying discs on their flight performance from the aerodynamics perspective. Design/methodology/approach The lift, drag and moment coefficients of the discs were measured experimentally using a wind tunnel. Three types of golf discs and four sets of simpler parametric discs were studied to analyze and isolate the effect of design factors on these aerodynamic characteristics. Full six degree-of-freedom simulations of the discs were performed to visualize their flight trajectories and attitudes. These simulations, combined with the experimental data, provide details on the well-known “S-shaped” ground-path traced by a flying disc. Findings This paper reveals two key parameters to evaluate the flight performance of a disc: its coefficient of lift-to-drag ratio (CL/CD) and, more importantly, its coefficient of pitching moment (CM). The latter influences the tendency of the disc to yaw from its intended path, and the former influences its throwing distance. Practical implications The work suggests that to optimize the flight performance of a disc, the magnitudes and gradient of its CM should be minimized and its trim-point shifted from origin, while its CL/CD should be maximized with a flatter peak. Originality/value In this paper, the design parameters and the aerodynamic characteristics of various types of flying discs are analysed, compared and discussed in depth. Recommendations of design improvements to enhance the performance of any flying disc are offered as well.

This study developed a new design of a low cost potentiostat circuit device. This device is an alternative electrochemical instrument applied for monitoring heavy metal ion in environmental water. It was developed to alleviate the cost burden of equipment procurement and due to the requirement for in-situ application since the existing commercialize devices are bulky and expensive. The main component of the device consist of electronics configuration of operational amplifier. The device was first modelled and simulated to acquire the design parameters and performance. The potential control algorithm was developed on open-source microcontroller platform. A dummy cell was used to validate the capabilities of the device.

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There are very few initiatives to engage students in learning about the sustainability of wind energy through Science, Technology, Engineering, and Mathematics education, also known as STEM. This awareness is essential for future generations to instill interest and understanding in the significance of sustainable energy. Therefore, a practical, hands-on Savonius turbine demonstration kit has been designed for Science, Technology, Engineering, and Mathematics (STEM) education. Two models of drag-driven vertical axis 2-bladed and 3-bladed Savonius turbines were built to generate electricity and integrated with a model house as part of the STEM turbine kit. It was fabricated in-house and could display power using LED lights and actuating a few mechanical devices. The experimental study in this project aims to investigate and analyze the influence of the number of blades on turbine power performance in terms of power coefficient and torque coefficient with respect to tip speed ratio. The results revealed that the 3-bladed Savonius turbine has a higher power coefficient than the 2-bladed at a tip speed ratio of 0.109. However, the torque coefficient decreased as the tip speed ratio increased due to an increase in the number of blades that eventually created a reverse torque. It is also observed that the 3-bladed turbine generated the highest power output of 1.28 Watt at a speed of 38.8 m/s. The results also discovered that all the components could run more efficiently using the 3-bladed Savonius turbine. This kit demonstrates the ability to contribute to the education system in developing countries, such as Malaysia by supporting the construction of an engaging educational process with practical integration and low production costs.