Maintaining satellite electronics within their maximum allowable operating temperatures is crucial for longterm reliability, yet increasingly power-dense payloads and miniaturized satellites introduce severe challenges. To meet the demand for efficient thermal management, this study leverages advances in additive manufacturing and explores triply periodic minimal surface (TPMS) heat sinks with phase change material (PCM) for space use, a growing area but with limited research. As part of the design development of the University of Technology Sydney's payload Matilda, this work examined how geometry, material composition, and orientation influence the performance of PCM-based thermal management modules. Five heat sink designs were investigated: hollow, gyroid, I-graph-Wrapped Package-graph (IWP), swirl, and radial plane fins. The heat sinks were 3D-printed from titanium and stainless steel, filled with paraffin wax PCM, and tested under vacuum at two power levels. Key parameters such as internal surface area and mass were analysed. Results show that, although material thermal conductivity influences temperature, design-dependent factors such as total metallic mass and internal structure distribution dominate heat dissipation. The gyroid achieved the lowest temperatures, though at the cost of increased mass, while mass-normalized performance identified the IWP lattice and radial-finned designs as most efficient. A mass-matched comparison of these two revealed nearly identical performance despite 27% difference in internal surface area, underscoring the role of total mass and internal geometry distribution. Orientation and initial PCM position had minimal influence, with less than 4 degrees C variation. These findings demonstrate that thermal performance is heavily affected by material properties, total mass, and structure distribution, with geometric complexity offering secondary benefits, and orientation and PCM position yielding minimal returns.

The thermal management of electronics in space presents unique challenges due to high waste heat generation, miniaturised device footprints, and the absence of convective cooling in vacuum environments. This study investigates the behaviour of a metallic heat sink under varying pressure conditions, from atmospheric pressure to high-grade vacuum, using experimental and numerical approaches. The thermal response of a stainless steel heat sink featuring plate fins was investigated at two power levels to simulate different heat loads of satellite avionics. The experiments revealed a significant rise in operating temperatures under lower pressure conditions, with temperatures in high-grade vacuum exceeding those at atmospheric pressure by up to 66%. A reduced-order numerical model was formulated and validated against experimental data, demonstrating strong agreement and providing an efficient tool for predicting heat sink performance in vacuum conditions. The findings underscore the critical impact of pressure on heat dissipation mechanisms and highlight the need for advanced thermal management strategies tailored for space applications. This work contributes to the understanding of heat sink behaviour across varying pressure environments, offering insights for the design of more effective thermal control in aero-and astrospace technologies.

The rapid miniaturization of modern electronics has led to significant overheating issues, which pose substantial risks to their performance, reliability, and service life. This study aims to address these challenges by proposing a novel heat sink design incorporating Triply Periodic Minimal Surface (TPMS)-based metal lattice structures embedded with a phase change material (PCM). A comprehensive numerical and experimental investigation was conducted on a 3D-printed PCM metal-lattice heat sink. By employing a three-dimensional unsteady numerical approach and the finite volume method, this study evaluated the metal lattice as a thermal conductivity enhancer. A parametric study was performed to assess the impacts of the heater power input, material, design, and applied heat flux direction. The tested materials were Stainless Steel (SS) and titanium (Ti), with paraffin wax as the PCM. The findings demonstrated that the TPMS-based lattice structure (P3) helps improve the heat exchange between the metal and PCM by facilitating gradual and uniform melting within the system. The SS (P3) heat sink showed up to a 9 % reduction in base temperature compared to Ti (P3) under heater power inputs ranging from 5.1 W to 8.6 W, attributed to its better thermal conductivity. The parametric analysis indicated that, when compared to radial fin design (P5) under multidirectional heat input, P5 returns 3 to 4 degrees C lower base temperature than P3 for SS and Ti under base-only heating case scenario. On the contrary, P3 outperformed P5 by maintaining side walls 6 to 8 degrees C cooler during side-only heating. However, the combined effect of base and side heating was found to be insignificant for both designs. The analysis concluded that although the radial fin design (P5) performs slightly better under base-only heating conditions, the TPMS design (P3) would otherwise outperform it, particularly in applications involving multi-directional heat input.

High computational power and miniaturisation of modern electronics lead to high heat generation, compounded by the decreased available area for heat dissipation. This challenge is exacerbated in space environments due to the lack of convection. Phase change materials (PCM) are a strong option for the passive thermal management of satellites. However, their behaviour in vacuum is unclear. This study experimentally investigates and compares the performance of non-PCM and PCM-based thermal control modules under atmospheric pressure and vacuum conditions. A stainless steel heat sink with internal planar fins was tested using a printed circuit board (PCB) to produce three input power levels, simulating the heat dissipated by satellite electronics. Paraffin wax was used as the PCM. The thermal performance is reported and analysed for both pressure conditions. A reduced-order numerical model was established to predict performance with low required computational effort. This work finds that electronics operating in vacuum displayed temperatures as much as 32.8% higher compared to those in atmosphere due to decreased heat dissipation resulting from the lack of convective heat transfer. In addition, PCM had a greater impact in reducing the electronics temperature in vacuum than at atmospheric pressure. The presence of 6 g of PCM lowered the electronics temperatures by up to 18.0 degrees C in vacuum, and by up to 12.3 degrees C in atmospheric pressure. That amount of PCM doubled the electronics operating time under both pressure conditions at high power. The findings of this work contribute to understanding the performance variances of non-PCM and PCM-based heat sinks under different pressure conditions to further improve the design of thermal management modules for satellites.

Actuator selection is critical in the design of human compatible robotics, such as prosthetics, exoskeletons, and humanoids. Each has its own set of parameters, from output specifications to package sizing and applicable environmental conditions. A multitude of design factors must be considered in selection, some are dictated by performance relations, while other engineering decisions are latent and unobserved. In biorobotic design, weight is often a key trade-off parameter with actuator performance. We analyze a database of over 1900 motors that are of relevant size for biorobotic designs to identify underlying trends that affect selection options. Selected motors range from 0.000013Nm to 3.66Nm in torque and 0.0016kg to 5.67kg in weight. We then generate Ashby-style charts to evaluate trends across motor selection dimensions. We find a wide disparity between manufacturers and where their actuators are specialized. The results provide a means for rapidly narrowing the selection space for designers, which is shown through an example application and reduces design time and improves the actuator selection.

Powder bed fusion is importance is growing with uses across industries in both polymer and metallic components, particularly in mass individualization. However, due to the relatively slow mass deposition speed compared to conventional methods, scheduling and production planning play a crucial role in scaling up additive manufacturing productivity to higher volumes. This paper introduces a framework combining discrete event simulation and a genetic algorithm showing makespan improvement opportunities for multiple powder bed fusion factories varying workers, jobs and available equipment. The results show that bottlenecks move among workstations based on worker and capital equipment availability, which depend on the size of the facility indicating a resource-driven constraint for makespan. A makespan reduction of 78% is achieved in the simulation. This shows the trade-off of worker and capital equipment to achieve makespan improvements. The addition of personnel or equipment increases production with further gains achieved by scheduling optimization. Two levels of job demands are analyzed showing productivity gains of 45% makespan improvement when adding the first worker and additional savings with scheduling optimization using a genetic algorithm up to 11%. Most research on additive manufacturing production has focused on the quality of produced parts and printing technology rather than factory level management. This is the first application of this methodology to varying sizes of these potential factories. The method developed here will help decision-makers to determine the appropriate number of resources to meet their customer demand on time, additionally, finding the optimal route for jobs before starting the production process.

Current applications of Fused Filament Fabrication in additive manufacturing tend to produce heavily anisotropic parts. This is largely due to the discretization of heterogeneous planar layers, resulting in weak thermal fusion bonding that fundamentally limits the strength of end-use parts. To improve the mechanical properties of these parts, this work develops a novel method to generate non-planar, stress-aligned layers and toolpath plan that is feasible on consumer hardware. The approach uses a region-based stress alignment scheme starting with select layers and preserving local boundaries and printability. This approach relies on the local rotation of sets of points on a surface to achieve coplanarity between mesh regions and their largest tensile stresses. Interest regions are weighted to high stress areas using local von Mises stress, with intermediate layers generated from linear interpolation between respective sets of aligned regions. The fitness of model slicings is assessed by analyzing the intrinsic coplanarity of each first principal stress vector on the sliced layers to that of the finite element mesh indicating how close layers are to the ideal alignment. Simulation results show fitness scores increased by up to 120% from commercial planar slicing. Physical testing of printed samples confirms mechanical property improvements and more ductile failure modes.

The recent advancements in miniaturization and multi-functionality of electronics have increased overheating risks, leading to unreliable performance and higher operating temperatures. To address this, a comprehensive numerical and experimental analysis of a 3D printed, stainless-steel, phase change material (PCM) radial fin heat sink design was performed. A three-dimensional unsteady numerical approach based on the finite volume method investigated the use of radial fins as thermal conductivity enhancers. A parametric study evaluated factors including power input, convective heat transfer coefficient, base thickness, fin thickness, and fin height. Paraffin wax was used as the PCM. To replicate the heat output of electronic devices, a constant power input was supplied to the heat sink base, capturing transient profiles of base temperature, volume average temperature, liquid-fraction, and velocity distributions. Results indicate that power input, convective heat transfer coefficient, and base thickness significantly influence performance more than fin thickness and height. Base temperature reductions with increased heat transfer, lower power input, and thicker bases were 81 %, 34.9 %, and 14.1 % respectively, while thicker and taller fins resulted in 4.3 % and 0.5 % reductions after 2000 s. The study suggests improved cooling performance with higher convective heat transfer coefficient (20 W/m2K < HTC < 40 W/m2K), thicker bases (2 mm < tbase < 3 mm), and thicker fins (1.5 mm < tfin < 2.5 mm) at constant power input. These findings contribute to the design and development of efficient heat sinks for high-power modern electronics.

Material extrusion additive manufacturing is an essential technology for rapid prototyping. The standard approach to planning the deposition toolpath for this technology builds each layer sequentially. Unfortunately this approach typically results in significant wasted motion, which is a barrier for use in industrial production. In this paper, we give a new method for toolpath planning that improves on the layer-based approach as well as our own previous methods that build toolpaths across layers. Our approach utilizes a Reeb decomposition on the input model, which is a geometric decomposition that allows toolpath planning over subcomponents of the model rather than over individual extrusion segments. This allows a top-down construction of toolpaths, and is highly effective. We test our new approach, which we call Reeb planning, over a benchmark of 50 models and achieve a reduction of 49.7% in wasted motion over standard layer-based methods. Our decomposition scheme also provides insight into model classification, which can be used for improved production planning.

Purpose: Computer-aided production engineering simulation is a common approach in the search for improvements to real systems. They are used in various industrial sectors and are a basis for optimization. Such production simulations have found limited use in the wool industry. This study aims to compare the performance of different woolshed layouts (curved vs linear). Design/methodology/approach: A discrete event simulation is constructed for both considered layouts in Siemens Technomatix Plant Simulation software. Data from an in-field observational visit to a working woolshed is used to validate the simulation model. The different layouts are compared in their base configuration and with equipment and worker changes to evaluate the impacts on throughput.Findings: In the base configurations, the curved layout reduces some worker travel time which increases production by 11 fleeces per day over the linear layout. The addition of an extra skirting table in the curved layout further increases throughout by 30 fleeces per day. The addition of more wool handlers does not have as large of an impact indicating that processing limits occur due to equipment capacity and shearer speed.Practical implications: This verifies the proposed curved shed layout improves production and gives farmers the ability to compute the long-term economic impact. The results also highlight that other processing stages in the shed need adjustment for more system gains.Originality/value: This is the first application of discrete event simulation to evaluate woolsheds operations and introduce multiple improvement scenarios.

In the context of Industry 4.0, manufacturing companies have been increasingly adopting digital technologies such as Internet of Things, data analytics and cyber-physical systems to seize opportunities for productivity improvements. At the same time, established manufacturing philosophies such as Group Technology have assisted companies in managing the complexity of production processes for decades. To support manufacturing management with more informed decision-making tools, the literature has been proposing new approaches that exploit the potential of digital technologies to enhance the effectiveness of traditional manufacturing techniques. This study focuses on Production Flow Analysis (PFA) as an established approach for Group Technology. Although the existing literature has been focusing on Artificial Intelligence (AI) based approaches to plan the change to Group Technology for decades, few studies rely on production data directly extracted from the factory floor. This is partly due to the fact that technologies such as sensors and data analytics have been increasingly adopted in recent years, and this has led to an increasing amount of data that can be exploited to develop models that can support decisions. In particular, in the context of Industry 4.0, process mining has gained increasing interest, as it provides a data-driven methodology to capture real production processes. The goal of this study is to explore how PFA has evolved in the last decade thanks to the adoption of digital technologies, and to investigate potential synergies between PFA and process mining. This study uses a structured literature review to map advances in industrial applications of PFA in relation to digital technologies, as well as process mining applications in manufacturing to present a future research agenda. This provides manufacturing managers with a structured overview of existing industrial applications and the digital technologies adopted to enhance decision-making tools.

As part of the propulsion system, the fluid dynamic features of the main nozzle can immediately affect the stability and efficiency of an air-jet loom. This study aims to optimize the fluid characteristics in the main nozzle of an air-jet loom. To investigate ways of weakening the effect of airflow congestion and backflow phenomenon occurring in the sudden expansion region, the computational fluid dynamics method is employed. Three-dimensional turbulence flow models for a regular main nozzle and 12 prototypes with different nozzle core tip geometry are built, simulated, and analyzed to get the optimum performance. Furthermore, a set of modified equations that consider the direction of airflow are proposed for better estimation of the friction force applied by the nozzle. The result shows that the nozzle core tip's geometry has a significant influence on the internal airflow, affecting the acceleration tube airflow velocity, turbulence intensity, and backflow strength of the sudden expansion region, and other critical fluid characteristics as well. Several proposed models have succeeded in reducing the backflow and outperforming the original design in many different aspects. Models A-60 and C-P, in particular, manage to increase the propulsion force by 37.6% and 20.2% in the acceleration tube while reducing the maximum backflow by 57.1% and 52.2%, respectively. These simulation results can provide invaluable information for the future optimization of the main nozzle.

Actuators are a vital component, and often the limiting factor in robotics and robotic-related applications like humanoids, exoskeletons, prosthetics and orthosis. Actuator selection is critical due to system design flow-on effects including weight, energy consumption and form factor. A designer's challenge is often to optimize the actuator to minimize size or weight and meet the performance specifications usually with trade-offs. This paper investigates the design impacts of selecting more suited actuators on the system through a representative humanoid configuration performing a task. It also looks at variations based on the scale of the humanoid using human anthropometric data for variations in limb lengths. The torques and speeds required at each joint to complete the task is simulated and the system design is updated to keep a constant member stress across all designs. The total energy and weight are calculated and used to compare actuator selection impacts. By knowing the extent of the flow-on effects actuator selection has on a configuration, and how this effect scales, designers are able to determine what investment should be allocated to locating the ideal actuator for their task.

Purpose: Computer-aided production engineering simulation is a common approach in the search for improvements to real systems. They are used in various industrial sectors and are a basis for process improvement. Such production simulations have found limited use in the wool industry. This study aims to compare the performance of different woolshed layouts (curved vs linear). Design/methodology/approach: A discrete event simulation is constructed for both considered layouts in Siemens Tecnomatix Plant Simulation software. Data from an in-field observational visit to a working woolshed and industry gray literature is used to validate the simulation model. The two layouts are compared in their base configuration and with equipment and worker changes to evaluate the impacts on throughput. Findings: In the base configurations, the curved layout reduces total worker travel time which increases production by 11 fleeces per day over the linear layout. The addition of an extra skirting table in the curved layout further increases throughout by 30 fleeces per day. The addition of more wool handlers does not have as large of an impact indicating that processing limits occur due to equipment capacity and shearer speed. Research limitations/implications: The sample size of the collected field data was small; some data have been collected from literature and not directly measured. Processing time is assumed to be distributed uniformly as a conservative distribution form. The study’s purpose is to evaluate relative differences in two different layouts using consistent worker parameters. Practical implications: This verifies the proposed curved shed layout improves production and gives farmers the ability to compute the long-term economic impact. The results also highlight that other processing stages in the shed need adjustment for more system gains. Originality/value: As the first application of discrete event simulation to evaluate woolsheds operations this work shows throughput gains are possible with layout, equipment, and worker changes to current practices. Additionally, this work shows the effectiveness of discrete event simulation evaluating woolshed designs. The results can be used to reduce costly experiments.

Rising energy prices and increasing competitiveness in the brewing industry challenge beer producers to reduce costs. To address this issue — and the environmental concerns over climate change — more energy-efficient brewing processes are required. The brewhouse consumes around one-quarter of the total energy demand in a brewery, especially wort boiling, where heat energy in the form of vapour is often wasted and presents a large potential for recovering energy. Although the technology for heat recovery during wort boiling is commercially available for large breweries, the development of equipment technology for craft and micro-breweries still lags behind. Based on a survey of Australian local craft and micro-breweries and a nano-brewery case study, we compare the evaporation rates during wort boiling for different operational parameters and use the results to verify a proposed mathematical model of evaporation from a kettle. We also propose and analyse options for re-utilising the recovered energy, such as pre-heating water for use in a subsequent process or storage for a later brew. Our study shows that the vapour released during the production of one litre of beer has the potential to heat 0.6 to 1.6 litres of water from ambient to 65°C. As for the potential energy savings and environmental impact, the case study nano-brewery can save approximately 5% of the brewhouse’s energy consumption or 2% of the energy required by the entire brewing process, while each surveyed brewery can spare 16 to 133 tonnes of CO2-e from being released into the atmosphere each year. These results reinforce the potential of recovering waste energy from wort boiling vapours in assisting breweries to become more energy-efficient, competitive and environmentally responsible.

Since its early days as a rapid prototyping technology, additive manufacturing has significantly evolved and become an important enabling technology for advanced manufacturing. Despite the benefits, its application in industry is not trivial as, for example, products need to be re-designed and processes changed, and it is not always the optimal manufacturing technology. Design for Additive Manufacturing (DfAM) is a key approach to support the successful use of additive manufacturing in industry and to bridge the gap between research and practice. Aside from design process and technology related methods and tools, DfAM also considers organisational and procedural aspects. To support the success of DfAM and as a result additive manufacturing, it is important to understand how industry needs are addressed by current DfAM methods/tools and related research activities. In this respect, a comprehensive analysis is missing. Therefore, this paper systematically analyses current research topics, fields and trends as well as industry needs and DfAM requirements from an engineering management perspective. Mapping them allows for a systematic discussion between academia and industry to identify the most pressing research needs.

Additive manufacturing has emerged as a next-generation technology for advanced fabrication. Fused Filament Fabrication (FFF) is the most widespread form of material extrusion additive manufacturing and has growing applications in large scale construction. Despite its advantages, FFF is limited by structural weaknesses introduced by cooling of the material between layers. This paper presents an approach to reduce the probability of failure for a given object under known loading conditions through improved toolpath planning which considers temperature decay. Our approach reorders the fabrication sequence to vary the time to print between layers such that the thermal stress induced in fabrication is reduced in regions most likely to fail at the expense of increasing thermally induced stress in less critical areas. In our simulation experiments, we found that our approach offers the greatest improvement when the rate of cooling is large enough for significant temperature decay to occur, but not so large that cooling occurs too quickly for the print order to have any effect. Our approach offers the potential to improve the performance of 3D printed components under known loading conditions by considering the temperature of the print in the planning of the toolpath.

Indoor spread of infectious diseases is well-studied as a common transmission route. For highly infectious diseases, like Sars-CoV-2, considering poorly or semi ventilated areas outdoors is increasingly important. This is important in communities with high proportions of infected people, highly infectious variants, or where spread is difficult to manage. This work develops a simulation framework based on probabilistic distributions of viral particles, decay, and infection. The methodology reduces the computational cost of generating rapid estimations of a wide variety of scenarios compared to other simulation methods with high computational cost and more fidelity. Outdoor predictions are provided in example applications for a gathering of five people with oscillating wind and a public speaking event. The results indicate that infection is sensitive to population density and outdoor transmission is plausible and likely locations of a virtual super-spreader are identified. Outdoor gatherings should consider precautions to reduce infection spread.

Current applications of Fused Filament Fabrication in additive manufacturing tend to produce heavily anisotropic parts. This is largely due to the discretisation of heterogeneous planar layers, resulting in surface artefacts, stress concentrations and weak thermal fusion bonding that fundamentally limit the strength of end-use parts. In an effort to improve the mechanical properties of parts produced by Fused Filament Fabrication, this work developed a novel method by which to implement non-planar toolpath generation for a conventional three-axis machine. Utilising Boolean-based mesh approaches, arbitrary sinusoidal surfaces were used to generate non-planar tool-paths for the test specimens. To do so, a point cloud representing a non-planar surface was triangulated to form a surface mesh. A Boolean intersection between this non-planar surface mesh and the specimen mesh was then used to return the non-planar surface bounded by the geometry of the specimen; an edge traversal technique was then employed to obtain three-dimensional toolpaths. The frequency and amplitude of the non-planar sinusoidal surfaces were incrementally increased from the planar case until the geometric limits of the print-head were reached. Test specimens were then manufactured on a conventional three-axis machine and subject to a three-point bending test. There was a strong negative correlation between the flexural moduli of the specimens and the frequency and maximum tangential angle of their non-planar surfaces, while there was a strong positive correlation between the toughness of the specimens and the frequency of their non-planar surfaces. Non-planar specimens also exhibited more prominent yield points, and were better able to dissipate energy and resist crack propagation. A key finding was the significant increase in plastic strain exhibited by the non-planar samples; certain specimen types were able to withstand an average of 250% more strain in the plastic region, when compared to the planar samples, before significant progression of fracture. This is demonstrative of a notable improvement in ductility and reduction of brittleness. Non-planar samples also saw improvements in fracture toughness of up to 60%; however, this is perhaps not as significant as it could be, as greater tangential angles rotated the fibres away from their ideal colinearity with the normal stresses induced by bending. This work serves as a proof of concept for the feasibility of non-planar implementations of Fused Filament Fabrication, and provides a framework for future work aimed at non-planar alignment of material extrusion with stress tensors. It is anticipated that stress-vector fields will be used to generate non-planar surfaces, aligning material extrusion directions with principal stresses.