guideline. The guideline should be followed in the future measurements to get better initial values for the rigid body calculations.
WinRemo can also be used to calculate dynamic response of the system by entering the external excitation forces to the model. The reason the rigid body modes are excited by the internal excitations, is because large engine cannot be considered perfect rigid body, and thus the natural modes we call rigid body modes, have not ideally rigid shape. Since WinRemo assumes the body rigid, and only external excitations can be entered to the program for the response analysis, it should be studied how large amplitude external excitation is needed for corresponding vibration response. In this way, by finding equiv- alent external forces for the internal forces, the fast and designer-oriented program could possibly be used for the response calculation taking also internal excitations into ac- count.
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APPENDIX A: CALCULATED ENGINE EXCITATIONS
W8V31 Excitations
W8V31 Engine data
W8V31 External forces & force couples
W8V31 Internal mass forces
W8V31 Internal gas forces
W16V31 Excitations
W16V31 Engine data
W16V31 External forces & force couples
W16V31 Internal mass forces
W16V31 Internal torsion excitations from gas forces
W12V31 Excitations
W12V31 Engine data
W12V31 External forces & force couples
W12V31 Internal mass forces
W12V31 internal gas forces
APPENDIX B: W8V31DF ENGINE RIGID BODY CALCULATIONS
Figure 46. WinRemo model of the W8V31DF engine. The large block consists of the whole weighed engine with flywheel. The second-largest block is the power take-off axle and the flexible coupling. The small boxes are feet for the flexible mounts and liquids in the engine. The small, numbered squares are stiffness elements for flexible mounts (1- 10), flexible coupling (11) and exhaust bellow (12).
Figure 47. Modelling of a mass element of an engine in WinRemo.
Figure 48. Modelling of a non-linear flexible mount in WinRemo.
Figure 49. Modelling of a linear flexible mount in WinRemo.
Figure 50. Modelling of flexible coupling in WinRemo
Results:
APPENDIX C: MEASUREMENT SETTINGS
Frontend settings for nominal speed and sweep & stop with ODS:
Nominal speed measurement settings
Sweep & stop settings
Front-end settings for hydraulic shaker measurement with sinusoidal sweep excitation:
Hydraulic shaker measurement settings with sinusoidal sweep excitation:
Frontend settings for hydraulic shaker measurement with random noise excitation
Hydraulic shaker settings with random noise excitation