The automotive industry is currently traversing through the electrification wave. Numerous manufacturers are directing focus to electrify their lineup and reduce emissions. In the frontier of heavy duty diesel trucks, electrification of auxiliary units remains an unexplored potential. An optimized cooling system functioning in sync with a controllable electric coolant pump attempts to reduce parasitic losses and emissions. The cooling flow requirements in challenging conditions may also be fulfilled. Although electric coolant pumps are found increasingly in passenger cars, the implication of independently operating them in a heavy duty diesel truck is an important objective to be explored. The purpose of this project is to generate different cooling system layouts coupled with electrical coolant pumps. The performance of these layouts is compared with the volume flows in a standard cooling system. Refined layouts which fulfill the cooling system requirements are chosen for verification. 1-D Simulation is used to correlate and verify the trends of the test rig data. The results show an adequate gain in the total volume flow across distinct layouts with the electric coolant pumps. However, numerous challenges are required to be overcome. / Bilindustrin befinner sig mitt i en våg av elektrifiering. Flertalet tillverkare fokuserar på att elektrifiera sitt produktutbud och att minska utsläppen. Inom forskningen kring tunga transporter med dieseldrivna lastbilar, är elektrifiering av kylsystemet ett outforskat område. Ett optimerat kylsystem som är reglerbart med en elektrisk kylvätskepump skulle potentiellt kunna minska energiförluster och utsläpp. Kravet på flödet av kylvätska vid utmanande driftsfall skulle också kunna bli bättre uppfyllda än för dagens system. Trots att det blir allt vanligare att personbilar har elektriska kylvätskepumpar, så har det inte utforskats vad det innebär att ha reglerbara elektriska kylvätskepumpar i dieseldriva lastbilar. Därför är detta ett viktigt område att utforska. Målet med detta projekt är att skapa olika kylsystemskoncept, där den elektriska kylvätskepumpen är en systemkomponent. Prestandan hos dessa principlösningar jämförs sedan med volymflödet i ett standard kylvätskesystem. Koncept som uppfyller kraven för kylvätskesystemet kommer att bli utvalda för vidare verifiering. 1-D simuleringar används för att hitta samband och verifiera mot trenderna som hittas i resultat från en testrigg. Resultaten visar en förbättring i det totala volymflödet för flera av lösningarna, som har en elektrisk kylvätskepump. Men det finns fortfarande flera utmaningar som behöver övervinnas.

The focus of this work is to determine the stress of the crank mechanism of the inverted piston aircraft engine Walter Mikron III C UL from the manufacturer PARMA - TECHNIK, s.r.o. The main method of calculation is the numerical finite elements method using the program ANSYS Workbench, the module Static structural and Transient structural. The approximate indicated cylinder pressure during the duty cycle was determined in the GT-SUITE software. The partial goals are to propose possible modifications in the construction of the crank mechanism and to state the possible power reserves of the engine. The diploma thesis also briefly summarizes the history and development of aircraft piston engines from the company Walter, which developed the engine, and the line of Walter Mikron engines.

Cam phasers allow improvements to the efficiency and emissions of internal combustion engines. The usage of hydraulic vane type cam phasers for heavy-duty applications have shown problems with oscillations during testing at Scania CV. To investigate the root cause of the oscillations a detailed 1-d simulation model has been created. The 1-d simulation model was calibrated and compared against measurements of a cam phaser system mounted on a physical engine. The 1-d simulation model of the cam phaser system was shown to be able to reproduce the oscillatory behavior seen in engine tests. But there are some concerns regarding the model's reliability, due to its dependence on the integration time step. It was determined that free air in the phaser chambers is causing the excessive oscillations. The source of the free air present in physical phasers are not yet fully understood, but the movement of the phaser control valve, opening and closing of the phaser chamber vents, in conjunction with motion of the phase oscillations has a significant effect on the phaser's chamber pressure, resulting in reduce pressures. The reduced pressures result in air being sucked in to the phaser, form both the oil control valve vent and external chamber leakages. Another potential sources of free air is dissolved air in the oil supply being released due to low pressures from oil pressure fluctuations. A potential solution to increase the stability of the phaser is to reduce the sources of air, by having an oil accumulator at the vent, limiting leakage, having a high and steady oil supply pressure, modifying the oil control valve ports to have a more gradual initial opening area and controlling the oil control valve appropriately. How to implement these implementations and evaluate them are left as future work. Potential improvements to get rid of the 1-d simulation model's dependence on the time step, increasing the model's reliability, are discussed, but not tested.

<p>One of the major challenges in the field of internal combustion engines is keeping up with the advancements in electrification and hybridization. Automakers are striving to design environment – friendly and highly efficient engines to meet stringent emission standards worldwide. Improving engine efficiency and reducing heat losses are critical aspects of this development. Therefore, accurate heat transfer prediction capabilities play a vital role in engine design process. Current methods rely on computationally intensive 3D numerical analyses, there is a growing interest in reliable simplified models. </p> <p>In this study, a 1D diesel engine model featuring predictive combustion was integrated with a detailed finite element thermal primitive based on the 3D meshing feature available in GT Suite. Coolant and oil hydraulic circuits were incorporated in the model. The model proves to be an effective means to assess the impact on heat rejection and engine heat distribution given by an engine calibration and operating conditions. </p> <p>This work also contributes to the advancement of virtual IC engine development methods by focusing on the design and tuning of complex engine system models using GT Power for accurate prediction of engine performance. The current processes in engine simulations are assessed to identify sources of errors and opportunities for improvements. The methods discussed in this work include isolated sub system level calibration and model evolution specifically address the issue of identifying noise factors and issues in smaller parts. Additionally, the study aims on improving the model’s trustworthiness by computing 1st law sanity checks, replicating real-life compressor map calculations and refining GT’s existing global convergence criteria. </p>