Abstract:
Torsional vibration in Internal Combustion Engines is an important phenomenon occurs due to excitation loads, cycle-to-cycle variations results from the force the burnt gases and to change in inerita forces generated by reciprocating parts during convertoin of rotary motion to the linear one . This conversion leads to twist torque on the crankshaft which, in turn, leads to high stresses causing its damage. The importance of the present study stem from the fact that this phenomenon cannot be detected till it leads eventually to system failure. There are several types of dampers to alleviate torsional vibration such as frictional, viscous, rubber and dynemic dampers but these types has the drawbacks of consumption of engine power and reduction of engine lifetime. The objective of this study is to use electromagnetic damper as this type of damper minimize power consumption, without getting in direct friction with the system in addition to quickness of response to engine excitation change. The methodology of our study is based on theortical treatement through writing a Matlab code to investigate the effect of damping coefficient on excitation during resonance condition.
It was found, through this study, that the optimal damping coefficient value is 0.2,0.3and 0.4 .in concordance with previous studies.
