Automatic Calculation of Torsional Vibrations on Marine Propulsion Plant Using Marine Two-Stroke Diesel Engine: Algorithms and Software

Abstract

For a sea-going ship to be built new or reconstructed, the main propulsion plant (MPP) consisting of a marine diesel engine (MDE), driving the ship propeller, is mandatory to be calculated with the torsional vibrations (TVs) in accordance with the Rules for the Classification and Construction of Sea-Going Ships, such as Russian Maritime Register of Shipping (RMR), DNV, ABS, and VR. The TV calculations (TVC) are conducted at normal working regimes and at misfire regimes (called by Normal or Misfire regimes relatively) with only one of cylinders of MDE while engine speed range covers from the minimum to maximum values of the operation speeds. The TVC on the MPP are incredibly sophisticated calculations and are conducted with special software for TVC. The paper presents the algorithms and software for automatic calculating the TVs (SATVC) basing on the made mathematical models, algorithms and coded in LabView by authors. The SATVC was automatic calculated the freedom TVs (FTVs), excited torsional moments (ETM), excited TVs (ETVs), permitted torsional pressures (PTP), and common management (CTVC). In the article were shown the probated results of TVC using the SATVC for the MPP on MV.HR.34000 DWT which built in Pha Rung Shipyard, Viet Nam.