Nauticus Machinery Knowledge Centre Help library Tools and Calculations Whirling and Axial Vibration Calculation
Module Description
The Whirling and Axial Vibration module in Nauticus Shaft Alignment provides advanced analysis of lateral (whirling) and axial vibrations in marine propulsion shafting systems. It helps engineers identify critical vibration modes, avoid resonance issues, and optimize shaft design for improved reliability and performance.
Key Features for Whirling Vibration Analysis
- Examines whirling vibrations due to shaft unbalance, gyroscopic effects, propeller overhange and entrained water.
- Calculates natural frequencies and vibration modes to identify the critical speed.
- Evaluates the influence of bearing stiffness, reaction points, and lubrication film stiffness.
- Integrates Campbell Diagram analysis for frequency and critical speed assessment.
Key Features for Axial Vibration Analysis
- Calculates natural frequencies and vibration modes to identify the critical speed.
- Supports thrust bearing properties and propeller entrained water effects.
- Identify the critical speed according to the various excitation orders.
Workflow
- Use the same fundamental shaft alignment model.
- Enable whirling/axial vibration analysis in Operating Condition page.
- Input system properties such as bearing lubrication film stiffness, thrust bearing effects, and propeller effects.
- Specify the dominating excitation order(s).
- Run calculations to get the results and determine critical speeds.
- Compare results with reference values and classification society limits.
- Apply design modifications if needed to mitigate resonance risks.
- Validate improvements through iterative simulations.