The New BMW Six-cylinder  Top Engine with Innovative Turbocharging Concept

Steinparzer, Fritz; Nefischer, Peter; Hiemesch, Detlef; Rechberger, Erwin

doi:10.1007/s38313-016-0104-4

Cited by 11 publications

(2 citation statements)

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“…However, current innovative engine design and materials allow overcoming these limits leading to engine blocks able to cope with maximum pressures up to 210 bar. 28 For this reason, the study does not only focus on the nominal limits of this engine but also in other plausible boundaries.…”

Section: Optimum Hrl With Pressure Constraintsmentioning

confidence: 99%

Assessing the optimum combustion under constrained conditions

Olmeda

Martín

Novella

et al. 2018

International Journal of Engine Research

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This work studies the optimum heat release law of a direct injection diesel engine under constrained conditions. For this purpose, a zero-dimensional predictive model of a diesel engine is coupled to an optimization tool used to shape the heat release law in order to optimize some outputs (maximize gross indicated efficiency and minimize NO x emissions) while keeping several restrictions (mechanical limits such as maximum peak pressure and maximum pressure rise rate). In a first step, this methodology is applied under different heat transfer scenarios without restrictions to evaluate the possible gain obtained through the thermal isolation of the combustion chamber. Results derived from this study show that heat transfer has a negative effect on gross indicated efficiency ranging from −4% of the fuel energy ( ṁfHv), at high engine speed and load, up to −8% ṁfHv, at low engine speed and load. In a second step, different mechanical limits are applied resulting in a gross indicated efficiency worsening from −1.4% ṁfHv up to −2.8% ṁfHv compared to the previous step when nominal constraints are applied. In these conditions, a temperature swing coating that covers the piston top and cylinder head is considered obtaining a maximum gross indicated efficiency improvement of +0.5% ṁfHv at low load and engine speed. Finally, NO x emissions are also included in the optimization obtaining the expected tradeoff between gross indicated efficiency and NO x. Under this optimization, cutting down the experimental emissions by 50% supposes a gross indicated efficiency penalty up to −8% ṁfHv when compared to the optimum combustion under nominal limits, while maintaining the experimental gross indicated efficiency allows to reduce the experimental emissions 30% at high load and 65% at low load and engine speed.

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Section: Optimum Hrl With Pressure Constraintsmentioning

confidence: 99%

Assessing the optimum combustion under constrained conditions

Olmeda

Martín

Novella

et al. 2018

International Journal of Engine Research

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“…Highly intensified diesel engines have received increasing attention in recent years as they are effective in dealing with the stringent standards on vehicle emissions and fuel consumption [1][2][3][4][5][6]. A highly intensified power output can be achieved by increasing the power density and increasing the engine speed.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Lips-Guided-Flow Combustion Chamber and Miller Cycle to Improve the Thermal Efficiency of a Highly Intensified Diesel Engine

Wang,

Cao,

et al. 2023

Sustainability

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An investigation into the lips-guided-flow combustion chamber (LGFC) and Miller cycle was conducted on a highly intensified diesel engine under rated power conditions to improve thermal efficiency. The radius and depth of the chamber bowl and lips were optimized to intensify the guided flow and fuel/air mixing. The experimental and simulated results show that the LGFC had a higher fuel/air mixture quality and quicker combustion rate, leading to a higher indicated power and higher thermal efficiency. A late intake valve closing (LIVC) Miller cycle with a higher expansion ratio of 11 and a lower compression ratio of 8.2 was used to control the energy distribution of the thermodynamic cycle and reduce the mechanical and thermal loads. The results show that the maximum combustion temperature was decreased by about 45 K and the thermal efficiency was improved by 2.1%. The research results are useful to guide the improvement in thermal efficiency through combustion chamber design and Miller cycle application for highly intensified diesel engines.

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