On the next page is a schematic diagram of an actual marine propulsion system consisting of an 6-cylinder diesel engine,

[answerhappygod]

On the next page is a schematic diagram of an actual marine
propulsion system consisting of an 6-cylinder diesel engine,
flywheel, coupling, clutch, shaft and gear propeller. A torsional
vibration damper is attached to the non-drive end of the engine.
Information on the system is given below:

On The Next Page Is A Schematic Diagram Of An Actual Marine Propulsion System Consisting Of An 6 Cylinder Diesel Engine 1 (46.39 KiB) Viewed 37 times

Use Holzer’s method to estimate the lowest four torsional
natural frequencies of this system to the nearest +- 0.1 Hz.
Also determine and sketch the mode shapes for each of the four
natural frequencies, assuming unit amplitude for the damper (mass
element number 1).
Assuming that the engine is a four-stroke type (giving four power
strokes per revolution in this 6-cylinder case), determine the
engine running speeds, in rpm, that would cause the frequency of
engine combustion torque pulses to coincide with these four system
natural torsional frequencies.
So that each student has a different system, the moment of inertia
of mass element number 10 (the flywheel) shall be replaced with one
of the following magnitude. Let I_10 be 6.2.
Where a section of shaft is labelled as ‘rigid’ simply combine
the adjacent inertias and omit the shaft.
You may (and probably should! – life’s too short) use any software,
including MATLAB and Excel.

On The Next Page Is A Schematic Diagram Of An Actual Marine Propulsion System Consisting Of An 6 Cylinder Diesel Engine 2 (88.71 KiB) Viewed 37 times

On The Next Page Is A Schematic Diagram Of An Actual Marine Propulsion System Consisting Of An 6 Cylinder Diesel Engine 3 (21.4 KiB) Viewed 37 times

Parameters Diesel engine rated power Diesel engine rated speed Crankshaft diameter Cardan shaft diameter Intermediate shaft diameter Propeller shaft diameter Speed ratio of engine to propeller Value 441 kW 1800 rpm 101.6 mm 111.5 mm 89 mm 111.5 mm 4.041:1
Engine Clutch Cardan shaft Intermediate Shal Carcan shaft Propeller 056.5 SA111 5200 16 1:20 926.911 1766 TORE Freelen 16365 (a) ko kk k k k k k kil KI , Kazka kiskis HEH Free-end b1-407 Cut ܚܕܐ ܕܕܐ ܙܕܐܕܕܐ ܕ:I; I:: I lis 10 12 12 I; I; I; I; I4 I; I; I; In 11 10 1.2737475 C Damper Engine Shafting Gear Propeller Flywheel Coupling Clutch (b)
c (damping coefficient) Cu=0.3 6oz C11,12= 0.02 Number 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11 12 13. 14. 15. 16. 17 18 19 20. 21. 22. 23. 24. 25. 26. 27. Table of values I Moment of Inertia) (kg m) k (stiffness) (MNm/rad) 0.11 0.79 0.28 Rigid 0.013 15 3.56 9.10 1.43 7.70 2.00 7.70 2.00 7.70 1.43 7.70 2.00 7.70 7.70 3.43 7.70 2.22 9.8 5.22 Rigid 5.22 0.202 6.75 18 0.55 30 0.55 18 1.9 Rigid 1.9 Rigid 0.94 2.798 0.94 96.83 0.826 3.751 0.131 Rigid 0.239 0.232 0.068 0.362 0.187 Rigid 4.174 G= 0.15