Modelling of Sheet Cavitation

Outline

Recently, a sheet cavitation model has been implemented in panMARE. Cavitation has a significant influence on the pressure distribution in the flow and occurs in many forms. A very common form is the sheet cavitation defined as a closed vapor region attached at the propeller blades. Sheet cavitation operates pressure fluctuations which in turn cause vibrations on the ship hull. In addition, cavitation can lead to noise and erosions as well as variations in the developed thrust and torque. Thus, it is important to develop a computational method to predict cavitation behaviour of propellers already in the design stage. The numerical sheet cavitation model implemented in panMARE is able to predict the length as well as the thickness of sheet cavitation on two- and three-dimensional geometries. However, the calculated cavity length does not always coincide very well to the results obtained by measurements or by viscous flow models. There are two main difficulties in the prediction of the exact cavity length. The first one refers to the determination of the detachment point of cavitation. The second problematical aspect is the numerical modelling of the cavity closure. The aim of this research work is the investigation of these two problems with reference to the improvement of calculation results for the sheet cavity length prediction.

Sheet cavity thickness on a propeller blade

Figure 1: Sheet cavity thickness on a propeller blade.


Requirements

Knowledge in hydrodynamics and CFD as well as coding experiences (C, C++ and XML).


Type of Project

We plan one Diploma or Master Thesis project about this topic.


Contact

For more information please contact:
Prof. Dr.-Ing. Moustafa Abdel-Maksoud
Dipl.-Math. Maria Bauer