HealthProp - BLLMCopyright: © MSE
HealthProp - BLLM
Life Prediction and Health Monitoring of Marine Propulsion System under Ice Impact - Bearing load and lifetime modelling
Shipping activities, traffic and operations in Arctic and Antarctic areas are increasing. In Antarctica, traffic from cruise ships is also increasing due to tourism activities. In addition, as a result of climate change, more ice is drifting toward the open ocean (marginal ice zone), increasing the likelihood of propeller-ice interaction. For both cruise ships and offshore vessels, extreme impulse loads are generated when ice strikes the propeller. This poses a major risk to safe operation. In addition, loss of propeller component life in icy water requires repair in port. How these stresses are transmitted through a propulsion system's drive train and how component life is affected is relevant to operators in terms of passenger safety and maintenance costs, as well as to owners and designers of new vessels. It is therefore of great value to develop high-fidelity models and simulation tools capable of evaluating these extreme loads, drivetrain behavior, and remaining component life with great accuracy. This applies to the mechanical loads on propellers, shafts, bearings, gearboxes, flexible couplings, electrical drivetrain components (if used), and propulsion motors themselves. Since the loads due to propeller-ice interaction are as yet poorly defined, inadequate estimates can lead to damage to the entire drivetrain and especially to the bearings. On the other hand, conservative estimates lead to large and expensive structures.
The main objective of HealthProp is to increase the reliability of the mechanical drivetrain of ships in Arctic and Antarctic service through model-based condition monitoring. To improve system reliability and increase operational safety under harsh environmental conditions, a digital twin platform for monitoring the propulsion system and drivetrain of ships is being developed. The MSE is involved in the joint project HealthProp as part of the sub-project BLLM ( Bearing load and lifetime modeling - BLLM) with the analysis and modeling of ice loads on the stress of journal bearings in the mechanical drive train. The overall objective of the BLLM sub-project is to analytically record the influence of ice loads on the bearings of the drive train and to take this into account when determining the journal bearing service life. The South Pole supply vessel SA Agulhas II will be used as a case study for the validation and application of the developed digital twin platform. To achieve the objectives, the following sub-objectives will be pursued:
- Identification of the predominant relevant damage mechanism: fatigue vs wear.
- Classification of powertrain loads into magnitude and frequency classes and determination of relevant load spectra in the powertrain on the radial journal bearings
- Scaling of relevant load spectra to a test bed surrogate model of the SA Agulhas II drivetrain.
- Identification of contact conditions under the influence of ice loads in the radial journal bearings of the SA Agulhas II by means of simulations in AVL Excite and test bench experiments
- Development of models to account for ice loads in the determination of journal bearing life
- Federal Ministry for Economic Affairs and Climate Action
- Projektträger Jülich