Firing Sequence Optimisation on a V20
As the number of possible engine firing sequences grows disproportionately with the number of cylinders, an efficient assessment of firing sequences becomes complex. Swiss engine builder Liebherr has investigated both torsional and non-torsional criteria on a 20-cylinder diesel engine design. This article is based on a paper presented at the recent Torsional Vibration Symposium.
1 Crankshaft Loading
In internal combustion engines, besides the quasi-static bending and torsional load coming from cylinder pressure and mass forces, the crankshaft is subjected to a considerable dynamic load caused by torsional vibrations. Thus, an analysis of the cranktrain’s torsional dynamics has been common since the 1930s ,,,. Since then, the central role of the firing sequence of multi-cylinder engines on torsional excitation has been well known and understood. However, with steadily increasing specific output and cylinder peak pressures, in combination with higher numbers of cylinders,...
KeywordsTorsional Vibration Intake Manifold Admissible Sequence Firing Sequence Main Bearing
The author would like to thank the Liebherr D96 project team for the intensive collaboration and various contributions.
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