Some Consideration for Behaviour of Propulsion Diesel Engine in Transient Condition

Abstract

It is said that the horse power of recent marine propulsion diesel engine corresponding to their ship's sizes has been reduced comparing with former ones. In transient operational condition, such engines with reduced power tend to work to the utmost of their power due to relatively enlarged inertia force of ships. Such being the case, it might be necessary for reconsideration of nowaday practice of design of propulsion system in view of strength. To meet this possible demands, the measuring have been made concerning to the torque acting on actual ship's propulsion shaftings. Through the measurement unexpected increases of the maximum torque from the normal value were observed during ship's crash astern operation, the increase rates of which spread out up to 1.6. In this paper, we will report the measuring results with additional breif study on the behaviour of propulsion diesel in transient condition.