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Life-long learning materials enabling the growth of Digital Twin competences
In recent times, Digital Twin and Discrete Event Simulations are some of the promis- ing technologies in enabling industry 4.0. Since the developments of these technolo- gies are recent, their definitions and representations vary. Accordingly, there is a need to develop learning materials for these concepts to better help users seeking to develop or improve in these areas academically and professionally. The thesis fo- cuses on the main goal, which is the creation of learning materials with an emphasis on lifelong learning. For this, the learning materials are developed on the guidelines of constructive alignment and Bloom’s taxonomy to better facilitate lifelong learn- ing among the users. The developed learning materials are also developed around real-world problems such that the content is relatable and relevant. In the next phase, the evaluation of these learning materials is done. This is done by procuring feedback from the focus groups stakeholders, industry-level simulation experts, self-analysis and reflection; the pilot study undergoes revision and necessary changes are made. The procured revised learning material hopes to serve as a guide for users seeking to develop learning materials to improve competence in the field of Digital Twin and Discrete Event Simulation.
Engine lubrication system model calibration and fidelity
In the present day, tough competition in the automotive industry and shorter timelines for the introduction of new passenger vehicles have forced vehicle manufacturers to cut down on de velopment time. Virtual simulations help in shortening the time vastly and increase efficiency in the development phase avoiding unnecessary waste. The engine is one of the most impor tant subsystems of a car making up the heart of any combustion-driven vehicle, the blood of this engine being the oil, making the lubrication system one of the most critical parts of any engine. With the help of today’s advanced technology, computer software programs like GT-Suite can be used to simulate and predict the oil’s behavior inside an engine in a rather accurate way. This report explores the calibration and validation process of a turbocharged four cylinders engine’s oil system and analyses its accuracy at steady- state conditions. A model of the engine’s oil system is given and the calibration process begins where nine dif ferent calibration parameters, i.e, oil flow rate multiplier, orifice hole diameters, thicknesses, and pressure drop multiplier are used. These are eventually reduced to just two parameters. The calibration process is carried through at a high main gallery pressure mode at tempera tures of 60 and 130 ◦C. Moreover, the system sensitivity is tested where different parameters like the bearing clearances and engine load among others are changed to see their effect on the simulations’ accuracy and time. The model is then validated at all pressure levels and differ ent temperatures. Successful calibration and tuning of the model have yielded highly accurate results in a rea sonably short computational time, thus achieving the most relevant part of this project.
Hydrofoil deployment mechanism for rescue boat: Lightweight and cost-efficient solution to deploy a hydrofoil from a mid-sized boat
Product development of a hydrofoil deployment mechanism A lightweight and cost-efficient solution aimed to be used in the Swedish Sea Rescue Society’s next-gen electric rescue boats. FREDRIK BYSTRÖM Department of Industrial Materials and Science Chalmers University of Technology Hydrofoiling boats are being introduced into commercial usage throughout the world. Being a relatively new phenomena (relative to the industries’ more established non-foiling boats) optimal ways of handling and controlling hydrofoils have not yet been discovered or established. This thesis aims to investigate a possible solution to the handling (restricted to managing lift and drag forces generated by a hydrofoil) and controlling of hydrofoils (restricted to deploying, retracting and controlling trim). The context in which this has been performed is on a moderately sized 2.6 ton and 8 meter long rescue boat from the Swedish Sea Rescue Society, aimed to be used in lakes and coastal areas in Sweden. Possible solutions have been investigated by following a typical new product development process between the phases of establishing requirements up until early detail design. Results include proof-of-concept CAD models that have been evaluated using FEA simulations. Findings suggest that a winch-based solution using HMPE-fiber synthetic rope is optimal as a means to lower overall weight. Furthermore, a support structure that allows for vertical linear movement whilst being exposed to lift- and drag forces from the hydrofoil is needed. Future work would entail proceeding with detail design with a focus on design-for-manufacturing and performing further stress- and weight optimizations.
Diesel combustion control with digital rate shaping
Due to the impact of the transport industry on the environment, stringent emission norms are being pushed for implementation. The real challenges for OEM’s are to keep up with the regulations. The transition to complete electric future is still distant, and the existing diesel engines must survive for at least 5-10 years. Therefore, OEM’s must achieve the legislative requirements with fuel consumption benefits using the available technology. One of the techniques available is diesel combustion control with digital rate shaping. Therefore, the thesis will investigate this method with triple pilot injection strategy and study the improvements in terms of fuel efficiency and emissions. The work is carried out in two different parts; first, the Injector capabilities were tested in FIE (Fuel Injection Equipment) test rig at different load points with shorter and longer dwell times for different fuel quantities at different rail pressures. The aim was to investigate for injector performance in terms of minimum possible dwell time, fuel quantity, repeatability, and robustness of the injector. Resultsshow inconsistent injector performance. Second, the combustion is studied in a single-cylinder test rig. The test was investigated for one specific load point. The Injector capabilities and boundary conditions for triple pilot injection were again tested. Based on the Rate of heat release curve, each parameter, i.e. dwell time, fuel quantities and rail pressures were manually varied. Next, design of experiments (DoE) was set up using ETAS ASCMO. Running the DoE point in single-cylinder test rig, a combustion model was created from this data. Dwell time, fuel quantities and rail pressure as input parameters different response curves were created to see effects of these parameters on emissions, bsfc and combustion noise. These curves are then used to define a calibration strategy. Optimisations performed in the software are verified in the single-cylinder test rig. The optimised injection strategy was validated in Gen IV Volvo multi-cylinder production engine. The results replicate the inconsistent performance of injector seen in FIE test rig and do not justify the supplier claim. However, based on the trend a description about how to efficiently balance the calibration to achieve lowest engine out emissions, combustion noise and achieve efficiency through model-based calibration is proposed.