Reducing Time-To-Pressure in Oil System of Combustion Engine with Oil Cooler
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Typ
Examensarbete på grundnivå
Program
Maskinteknik 180 hp (högskoleingenjör)
Publicerad
2018
Författare
Hellsten, Axel
Pettersson, Oskar
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The time-to-pressure in the oil system of an internal combustion engine is important to ensure that all moving components in the engine gets the lubrication and cooling needed. If the time is too long the friction between moving parts will cause wear which in turn can lead to an engine breakdown. There is a large pressure drop over the oil cooler in VEA GEN3 which is one of the main causes for the long time-topressure during cold starts. The conditions when this issue occurs are very extreme with temperatures at -30 °C. During these very low temperatures the oil viscosity behaviour changes rapidly where small temperature variations make huge difference. This bachelor thesis aims to reduce the time-to-pressure by designing a a technical solution that bypasses the oil cooler. The bypass valve has been developed from a conceptual phase into a functional prototype. By using different methods to create concepts and thereafter evaluate them, the project ended up with two concepts that were developed further. 3D models were created in CAD that were used to do CFD simulations later on. The calculated CFD-results of the pressure drop over the bypass valve were to be verified by producing a properly functional prototype. With the bypass prototype installed on an engine, in a cold climate chamber, measurements were done and compared to baseline runs. The results of the CFD-simulations showed positive indications of a large reduction in pressure drop with the bypass installed. The simulation results were verified by real test results where time-to-pressure was reduced by 50% in comparison to the baseline engine. The project thereby accomplished the task to manage time-topressure below 4 seconds.
Beskrivning
Ämne/nyckelord
Produktion , Transport , Innovation och entreprenörskap (nyttiggörande) , Maskinteknik , Strömningsmekanik och akustik , Production , Transport , Innovation & Entrepreneurship , Mechanical Engineering , Fluid Mechanics and Acoustics