Ship

A useful help for marine propulsion system designers

Cheap, numerical methods that provide more information instead of expensive experimental tests with limited information. That is one of the things that Mohammad Hossein Arabnejad Khanouki will present when he is defending his PhD thesis Assessment of cavitation erosion risk based on single-fluid simulation of cavitating flows.
​High-performance marine propulsion systems such as propellers and water-jet pumps deal with cavitation erosion at some point in their operations. Cavitation erosion in a marine propulsion system usually translates into a decrease in its durability and can also cause vibration and noise in the system. To avoid these consequences, companies manufacturing these systems usually estimate the risk of cavitation erosion in the design process. Nowadays, this estimation is performed through experimental tests which are quite expensive and provide limited information. 

“In my thesis, we present numerical erosion assessment methods, that form an alternative to these experimental tests. These numerical methods are relatively cheap and they can provide more information about the origin of high erosion risk in a system. Knowledge of this origin can help the designer of marine propulsion systems reduce the risk of cavitation erosion” says Mohammad Hossein Arabnejad Khanouki.

Around 80-90 percent of the world trade is transported by ships using one type of marine propulsion systems. These propulsion systems burn mostly carbon-rich fuels such as heavy diesel which for sure have many environmental impacts. To reduce these impacts, it is essential to design high-performance marine propulsion systems. One of the biggest challenges in the design of such a system comes from the fact that it is difficult to assess the risk of cavitation erosion in the design process using current methods. 

“In my project, we developed numerical methods which can potentially make this erosion assessment easier” says Mohammad Hossein Arabnejad Khanouki 

Applied to a commercial water-jet pump​

His PhD thesis is performed in close collaboration with Kongsberg Maritime, a company producing different types of marine propulsion systems. The numerical erosion assessment method developed in his thesis is aimed at complementing the erosion assessment methods currently used in this company. 

”This numerical method is applied to a commercial water-jet pump designed by Kongsberg Maritime in the last part of my thesis. The results in this part can be viewed as the showcase on how the developed method can be used in the design process of water-jet pumps”.

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Published: Thu 24 Sep 2020.