Interfragmentary movement (IFM) of bone fragments in an external fixator is essential for successful fracture healing. A thorough validation of results at the precision level required for accurate IFM measurement has not been extensively conducted in past studies. This paper aims to demonstrate through experimental and theoretical investigations that camera-based systems can be...
Rubber's unique elastic and viscous properties make it essential in engineering applications, particularly in industries such as automotive, construction, and mining. For example, in mining, vibrating screens often experience excessive vibrations during start-up and shutdown, potentially damaging machinery and reducing lifespan. Effective vibration isolators are crucial to...
Soft robots open many possibilities to embed intelligence within the structure of a robot. However, central control of external valves and many control lines typifies pneumatic soft robots. This study proposes a soft pneumatic pattern generator to control the activation oftwo pneumatic actuators simultaneously. The concept mimics biological locomotive control, where nerve...
The transition to green energy is a pivotal endeavour for countries worldwide, and South Africa has placed a substantialfocus on wind energy in pursuit of this transition. This paper delves into the intricate relationship between the cost of finance and South Africa's transition to green energy, particularly within the wind sector. The energy transition presents an opportunity...
The finite element method (FEM) is utilised in evaluating stresses in keyways of shafts loaded in torsion. These stress values are divided by their corresponding nominal stresses to arrive at so-called stress concentration factors, which are compared against published charts and experimental results for specific reference cases. FEM has become ubiquitous in the analysis and...
Accurate mechanical property charac-terisation of high-temperature high-performance materials, such as additively manufactured (AM) Inconel 718 (IN718), is crucial to ensure the reliability of components. A sud-den drop in strength accompanied by significant embrittle-ment occurs in wrought IN718 near 700 °C. It is not clear whether AM IN718 exhibits this behaviour. The high cost...
Wind fleets have become significant en-ergy sources within national grids. However, future expan-sion of wind fleet capacity may result in little incremental benefit due to the inability of present grid architectures to absorb high levels of excess generation. Determining the upper economic limit is a topical issue but its solution is complicated by variations in energy system...
A short overview of the application of schlieren and shadowgraph image construction has been presented, focusing on its use in interpreting compressible CFD data. Numerical flow visualisation methods have been used for the validation of numerical models of real flow fields but are also a valuable tool for identifying and inter-preting flow field features and provide a useful...
As the world shifts towards renewable energy sources, newer and larger projects come to fruition every year. Renewable energy projects require a complex analysis before proceeding with development. Part of this analysis procedure is resource assessment. This research aims to determine the viability of using open-source software for industry applications. This is performed through...
The application of deep learning algorithms for fault identification in wind turbine components is contingent on extensive data. Such data is often scarce, especially in the faulty category. While adversarial data augmentation helps, biases from the original data persist, and larger datasets strain computational resources. As a solution, experts are turning to transfer learning...
A review of past investigations into the fatigue behaviour of structural adhesives and bonded joints in fibre-reinforced polymer composites is given. An overview of the structural adhesives used in general bonded joint applications is first provided, followed by an experimental fatigue testing of these bonded components. The aspects that influence fatigue strength and fatigue...
The Synchrotron-light for Experimental Science and Application in the Middle East (SESAME) facility is in the process of designing, procuring, and installing a new beamline for tomography (BEATS). The BEATS experimental hutch, hosting sample and detectors, will be located 43 m away from the undulator in the synchrotron ring. Noise in the form of vibration originating from...
Three-dimensional printing, widely known as additive manufacturing and metal additive manufacturing (MAM), forms part of manufacturing technology. It has gained attention in the last couple of years due to its high-efficiency manufacturing abilities. MAM can be classified either by different feedstocks, such as powder or wire, or different energy inputs (laser, electron beam and...
This paper presents a concept and case study implementation for a system of digital twins (DTs) aimed at supporting the management of railway infrastructure maintenance. The system of DTs includes DTs and software services. The case study uses, as physical asset, a subset of the railway infrastructure managed by the Passenger Rail Agency of South Africa (PRASA). The DT system...
This study focuses on experimentally validating the performance of XFOIL, a sophisticated software airfoil analysis tool used for approximating lift and drag coefficients. XFOIL output data was incorporated into a theoretical model simulating a variable pitch rotor system operating in a hovering state. The output of the Blade Element Momentum Theory (BEMT) rotor model is compared...
Surface dust can be a source carrier of viruses, bacteria and air pollution which entail common health issues such as asthma attacks, chest tightness, wheezing and difficulty in breathing. Visually perceived, cleanliness is one measure of indoor air quality and is the subjective assessment of cleaning quality. The aim of this work is to use pattern recognition mediated through a...
The purpose of this study was the development and experimental validation of a novel portable tactile braille reading device. This design aimed to address the lack of quality braille reading material in South African schools dedicated to the blind and visually impaired. The design was divided into four subsystems: the actuation of the refreshable braille display, the mechanical...
Axial flow fans are fundamental to air-cooled condensers. While they provide the air flow for heat transfer, they also generate noise, which is a growing environmental concern. Sound reflections are characterised in an existing fan performance test facility, which does not conform to fan noise measurement standards. Corrections to the measured SPL spectrum is deduced along with...
This project entailed the design, manufacture, and testing of a test setup with the ability to measure all load components acting on tillage and planting implements. In future, data obtained with the test setup can be used to perform accurate design calculations, as input into finite element simulations, and to perform accurate fatigue analysis. The design of implements can...
This study investigates the potential gains in operating volume flow rate and static efficiency of an induced draught axial flow fan system. These gains are achieved through pressure recovery, i.e. the conversion of dynamic pressure at the fan exit into static pressure. Pressure recovery is achieved using downstream diffusers, stator blade rows, and combinations of these. Three...
2021 R&D Journal Editorial Letter Kristiaan Schreve (Editor) 2021 was a good improvement over 2020. The new papers received is still low, but picking up from 2020. The required number of 10 papers were published. Interestingly, four papers had at least one international author. The slump in 2020 was not a problem for the caretakers of the SciELO index and they informed me that...
The flow of air past a smooth surface-mounted hemisphere is investigated numerically using six common RANS turbulence models and seeking steady flow solutions. Where possible, the turbulence models are applied using standard wall functions, resolving the viscous sublayer, and the enhanced wall treatment option in ANSYS Fluent. Results of the simulations are compared against...
Soft materials, such as soft biological tissue and soft silicone rubber, are non-linear materials which require the classical uniaxial and biaxial tensile testing methods for characterisation. Unfortunately, in special cases, such as for soft biological tissue, the samples are smaller than 10 mm χ 10 mm in size and these classical tensile testing methods produce unwanted stress...
A high performance, newly-developed wire-woven bulk diamond (WBD) ventilated brake disc is introduced to reduce the operating temperatures and mass of conventional brake discs. The use of the highly porous material requires a deeper understanding of the mechanical stresses developed within a brake disc to be developed to improve the disc core strength to withstand the high...
A water-wedge is often suspected to be the root cause for short-term overheating in fossil-fuelled boiler superheaters. However, it can be argued that evaporation of the water-wedge would cool the tube sufficiently and prevent overheating. This study aims to determine if the thermo-physical conditions occurring at low loads support this claim by studying the transient behaviour...