This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Combining Thermodynamics and Design Optimization for Finding ICE Downsizing Limits
Technical Paper
2014-01-1098
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The mass and overall dimensions of massively downsized engines for very high bmep (up to 35 bar) cannot be estimated by scaling of designs already available. Simulation methods coupling different levels of method profoundness, as 1-D methods, e.g., GT Suite/GT Power with in-house codes for engine mechanical efficiency assessment and preliminary design of boosting devices (a virtual compressor and a turbine), were used together with optimization codes based on genetic algorithms. Simultaneously, the impact of optimum cycle on cranktrain components dimensions (especially cylinder bore spacing), mass and inertia force loads were estimated since the results were systematically stored and analyzed in Design Assistance System DASY, developed by the authors for purposes of early-stage conceptual design.
General thermodynamic cycles were defined by limiting parameters (bmep, burning duration, engine speed and turbocharger efficiency only). The unprejudiced assessment was based on variability of any other engine design feature. Holistic approach to all engine systems impacting brake efficiency and sensitivity analysis to yet unknown parameters occurred to be very robust tool with sometimes surprising results, giving impulse for the future engine research. The shortest combustion angle or unlimited peak pressure has not yielded the best results due to the same reasons. Too large stroke is disabled by mechanical efficiency, too small speed due to wall heat loss. Too efficient internal cycle leaves too small energy for a TC drive. Brake efficiency reached for passenger car engine is less than 50% if no waste heat regeneration is employed. The mass of cranktrain was estimated for limited fatigue safety factor and bearing loads.
Comprehensive approach to iterative concept and configuration/parametric optimizations of thermal machines with internal combustion explained the limits achievable in the future. The procedures were described and stored in DASY environment. Coupling of the results to lightweight vehicles with properly scaled individual components and accessories of downsized/downspeeded engines is possible in this approach. Although not all methods for reaching the predicted optimum parameters have been already mastered, the study presents good base for finding new engine layouts and assessing their feasibility already in the concept phase.
Recommended Content
Authors
Citation
Bogomolov, S., Dolecek, V., Macek, J., Mikulec, A. et al., "Combining Thermodynamics and Design Optimization for Finding ICE Downsizing Limits," SAE Technical Paper 2014-01-1098, 2014, https://doi.org/10.4271/2014-01-1098.Also In
References
- Eilts , P. , Stoeber-Schmidt , C. , and Wolf , R. Investigation of Extreme Mean Effective and Maximum Cylinder Pressures in a Passenger Car Diesel Engine SAE Technical Paper 2013-01-1622 2013 10.4271/2013-01-1622
- Hyvonen J. Higher Efficiency for Further Downsizing; Example from Large Bore Medium Speed Engines (Wärtsilä) High Efficiency IC Engine Symposium SAE 2013
- Curtis E. Near Term Combustion System Development and the Influence of Transmissions, Drive Cycles and Fuels (Ford Motor Company) High Efficiency IC Engine Symposium SAE 2013
- Reitz R. Reactivity Controlled Compression Ignition (RCCI) for Ultra-High Efficiency IC Engine Operation with Low NOx and PM Emissions Plus Transient Control High Efficiency IC Engine Symposium SAE 2013
- Bogomolov , S. , Mikulec , A. , and Macek , J. Development of Design Assistance System and Its Application for Engine Concept Modeling SAE Technical Paper 2011-37-0030 2011 10.4271/2011-37-0030
- Hejlsberg A. , Torgersen M. , Wiltamuth S. , Golde P. 2010 C# Programming Language, The 4th
- Kim Mifa , Hiroyasu Tomoyuki , Miki Mitsunori , Watanabe Shinya 2004 SPEA2+: Improving the Performance of the Strength Pareto Evolutionary Algorithm 2 Parallel Problem Solving from Nature - PPSN VIII, 8th International Conference , proceedings 742 751
- Bogomolov S. , Mikulec A. , Macek J. , Valasek M. , Doleček V. 2012 Knowledge-Based Design and Optimization of Engines THIESEL 2012 Conference on Thermo- and Fluid Dynamic Processes in Direct Injection Engines
- Macek , J. , Fuente , D. , and Emrich , M. A Simple Physical Model of ICE Mechanical Losses SAE Technical Paper 2011-01-0610 2011 10.4271/2011-01-0610
- Vítek , O. , Macek , J. , and Polášek , M. New Approach to Turbocharger Optimization using 1-D Simulation Tools SAE Technical Paper 2006-01-0438 2006 10.4271/2006-01-0438
- Macek , J. , Dolecek , V. , Srinivasan , S. , Tanner , F. et al. Optimization of Engine Control Strategies During Transient Processes Combining 1-D and 3-D Approaches SAE Technical Paper 2010-01-0783 2010 10.4271/2010-01-0783
- Heywood J.B. Internal Combustion Engine Fundamentals McGraw Hill 1998
- Macek J. Optimization of Using Fuel Chemical Energy in Reciprocating Engines Doctor of Science Dissertation Czech Technical University 1989 631
- Macek J. , Foglar P. , Holmberg S. The Development of Working Cycle and Design of a Four-Stroke, Medium Speed, Heavy Fuel Engine of 275 mm Bore CIMAC Paper Oslo 1985