Vertical axis wind turbine performance prediction: a new approach to the double multiple streamtube model

The vertical axis wind turbines (VAWT) have been suffering an increased acceptance for urban wind turbines integration in the future smart grid for decentralized generation (DG). The VAWT have several advantages over the more conventional horizontal axis wind turbines (HAWT): the smaller number of components; low sound emissions; their insensitivity to fast changes in wind flow direction; a lower architectural visual impact; the ability to operate closer to the ground; and others. But, the VAWT aerodynamic performance is more complex to simulate and predict due to its three dimensional operation. Several mathematical models have been presented to predict the VAWT performance, such as the double multiple streamtube (DMS) model. With the aim of presenting a tool to ease the study of complex shaped VAWTs, being at the same time able to be easily integrated in computational design tools, a new approach to the DMS model is presented in this paper

Implementing TPM supported by 5S to improve the availability of an automotive production line

The maintenance management is a topic of strategic importance for automotive manufacturers. In fact, an effective maintenance process and a preventive maintenance (PM) procedure can significantly reduce the risk of equipment failures that can lead to downtime on the production lines. However, due to the complexity of an automotive production system, the risk of failure on a crucial piece of the production equipment cannot be entirely avoided. The study made in this paper aims at improving the availability of a critical production line through the total productive maintenance (TPM) methodology and supported by Lean Maintenance tools. An analysis is made of the initial condition of the line where the main problems are identified by employing several tools for this purpose, such as Mean Time between Failures (MTBF), Mean Time to Repair (MTTR), Overall Equipment Efficiency (OEE) and Availability (A). In response to the identified problems, an action plan is developed and implemented in order to find the root cause of the high number of malfunctions and faults in one of the line’s equipment with the use of 5S tools, visual management, and maintenance progress, as well as the development of a training program to increase operators’ skills. The results of such actions were positive as the line became more organized, the value of the MTBF increased, the MTTR value decreased, and consequently the overall availability increased.info:eu-repo/semantics/publishedVersio

A new concept of automated manufacturing process for wire rope terminals

30th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM2021) 15-18 June 2021, Athens, Greece.The products related to automotive industry need to be extremely competitive. The metallic wire ropes used to open doors in the vehicles are based on a braided wire rope provided with accessories. The more expensive is the vehicle, the more complex is the required final wire rope. In order to prevent the corrosion and reduce noise, the internal metallic cable can be coated with a polymer via extrusion. However, this coating needs to be removed from the extremities of the metallic cable, allowing the zamak injection of the mechanical terminals, preventing die casting defects. Nevertheless, the standard machines able to produce the mechanical terminals by die casting process were always prepared to work only with non-coated metallic cable. Customers demanding coated metallic cables impose the need to adapt the standard machines to this new reality. Thus, new systems needed to be added to the standard machine, allowing the metallic cable strip operation. Moreover, this operation needs to be added to the process but without repercussions on the cycle time. Different approaches were studied and tested in order to find the best solution. The new device was designed and produced, allowing its test in real conditions. The system based on just one blade did not show satisfactory results, being necessary the use of a system based on multiple blades. The new device, when connected to the standard machine, allows to produce wire ropes up to 2.5 meters long, striped in both sides, letting the die casting injection of the zamak terminal in one extremity, with a cycle time of 7 seconds (1000 wire ropes per hour, as they are produced in couples).The authors would like to thank Mr. Mário Cardoso for his support and commitment with this work, providing all data necessary to carry out this development. The authors would like to acknowledge financial support from Fundação para a Ciência e Tecnologia (grants: UID/EMS/00667/2019 and UID/UIDB/CPO/04058/2020info:eu-repo/semantics/publishedVersio

Optimizing the agroforestry residual biomass supply chain: A disruptive tool for mitigating logistic costs and enhancing forest management

In a world with different energy needs, and more focused on renewable energies, biomass makes a very positive contribution. As a way of not creating more pressure on the forest, reducing the combustible loads of the forest, and reducing forest fires, residual biomass becomes an interesting resource. However, logistical costs and lack of information are threats to this valorization. In this sense, the objective of this work is to propose a technological tool (concept and prototype) that allows in an easy way and with high usability to connect the various stakeholders. This study began with an analysis of the state of the art, firstly carrying out a systematic review of the literature, accompanied by a benchmarking that led to a consolidation of the concept in a first phase, which was then followed by the construction of a prototype using the Figma tool. Thus, this study resulted in a disruptive tool that could optimize the information flow between the stakeholders, and that could result in benefits for all of them. The study presents some insights that can be used in the success of future projects in this field