Title data
Diwisch, Pascal ; Glenk, Christian ; Rieg, Frank:
Optimierung des Ladungswechselprozesses eines Zweitakt-Doppelkolbenmotors durch Simulation, Berechnung und Neukonstruktion von Brennraum, Ansaug- und Abgaskanälen : Optimization of the gas exchange of a split-single two-stroke engine through simulation, calculation and redesign of combustion chamber, intake- and exhaust ports.
In:
NAFEMS; ESI Group
(ed.):
NAFEMS 18 DACH Conference: Berechnung und Simulation : Anwendungen, Entwicklungen, Trends. -
Bamberg
,
2018
. - pp. 184-187
ISBN 978-1-910643-14-3
Abstract in another language
Biogas processed to natural gas, or even biogas itself is regardless of weather conditions and provides a CO2-neutral energy carrier. Compared to conventional fuels the use of natural gas has significant advantages. Natural gas is both knock-resistant, causes less exhaust emissions and at the same time has a favorable carbon to hydrogen Ratio, which has a positive effect on the efficiency.
While the engine research concentrates predominantly on four-stroke engines, two-stroke engines have significant advantages: a higher performance and a balanced engine running with less installation space at the same time. In addition, numerous components are omitted, which in four-stroke engines control the gas exchange. Compared to two-stroke engines it is regulated by the piston itself. The significantly lower complexity of two-stroke engines reduces the moving masses in the engine and has a positive effect on the resource-saving production as well as on the production costs. However, a major disadvantage of conventional two-stroke engines is due to short-circuit currents increased fuel consumption and therefore unburnt emissions of Hydrocarbons. However, the benefits of a gas operation connected with selected, positive characteristics of the two-stroke engine technology showed an interesting engine concept for the use as range extender. Therefore the charge cycle has to be perfected and a suitable concept for natural gas injection or two-stroke engine has to be developed.
One possibility offers the concept of the split-single two-stroke engine. At this Construction, two pistons share a common combustion chamber. As a consequence the outlet piston goes ahead of the inlet piston. Thus, the outlet port is closed in front of the inlet port. This shows a possibility of decrease short circuits and thus Hydrocarbon emissions. This article shows the application of a combination of Computational Fluid Dynamics and analytical relationships to determine optimal filling by lowest short circuits. To achieve these goals the combustion chamber, the intake- and the exhaust ports are optimized. Therefore the compression ratio could be improved by 48%, while the trapping efficiency raised by 10%. The next step is the production of a prototype and the validation on the test bench.