For MARIN Academy we are looking for a student for the folowing MSc Thesis:
A substantial part of hydrodynamic research is related to the efficiency of marine propulsors. An increase in propulsor efficiency leads to a decrease in the required propulsive power and therefore to a reduction of fuel costs. Accurate predictions of propulsor performance for design and off-design conditions is therefore essential in the design and analysis process.
Traditionally, to determine thrust and torque characteristics, propulsors are tested experimentally in a model basin in an open-water test set-up. These tests are done at small/model scales and at lower Reynolds numbers than the real/prototype scale. Next to experiments, numerical methods play an increasing role in the propulsor design process. While in the 90’s, beginning of 2000, lifting line methods or boundary element methods were the tools for propeller design, currently viscous-flow CFD methods are more and more used for both design and analysis of propellers. Advantages of CFD include the modelling accuracy, the amount of detailed information extracted from the simulations and the possibility of model and full scale analysis.
In this thesis work, the major objective is to analyze modern propellers both at model and full-scale using CFD, and to quantify the scale-effects on their performance and flow characteristics (see Figure 1). The work will be done mainly at Wärtsilä, using ReFRESCO ( www.refresco.org ) CFD code and comparing its results with STAR-CCM+ CFD package. All this will be based on previous work done both at Wärtsilä and at MARIN (see references -). The following tasks are envisaged:
- Literature study
- Choose appropriate test-cases (at least 3) to be tackled. Prepare geometry and grid
- Perform thorough Verification study at model-scale. Validation exercise
- Perform thorough Verification study at full-scale. Validation exercise if possible
- Study influence of turbulence models
- Study influence of laminar-turbulent flow transition
- Study influence of roughness
- Quantify scale effects (study influence of Reynolds number)
- Rijpkema, D. and Vaz, G., “Viscous Flow Computations on Propulsors: Verification, Validation and Scale Effects”, In Proceedings of RINA-CFD2011, London, UK, March 2011.
- Baltazar, J., Rijpkema, D. and Falcão de Campos, J., “On the Use of the ϒ-Reθ Transition Model for the Prediction of the Propeller Performance at Model-Scale”, In Proceedings of SMP2017, Helsinki, Finland, June 2017.
- Bulten, N., Stoltenkamp, P., “Full Scale CFD: the end of the Froude-Reynolds Battle”, In Proceedings of SMP2017, Helsinki, Finland, June 2017.
- Eça, L., Lopes, R., and Vaz, G., “Validation Exercises of Mathematical Models for the Prediction of Transitional Flows”, in Proceedings of 31th Symposium on Naval Hydrodynamics, Monterey, CA, 11-16 September 2016
- Eça, L. and Hoekstra, M. “A Procedure for the Estimation of the Numerical Uncertainty of CFD Calculations based on Grid Refinement Studies”, Journal of Computational Physics, 262, 104-130, 2014.
The duration is 9 months. The startdate of the internship period can be determined in consultation with the supervisors.
- Fluid Mechanics Basics
- CFD basics
- Linux knowledge
- Guilherme Vaz, Arjan Lampe (MARIN) and
- Petra Stoltenkamp, Maarten Bijlard (Wärtsilä).