Suction wing propeller

Concept

Among the various wind propeller concepts, which are suitable with cargo ship operations, the suction wing concept appears as the most promising one. This concept shows numerous advantages :

  • Satisfactory aerodynamic performances on a large range of operating conditions
  • Attractive energy efficiency
  • A moderate size able to generate a significant force
  • An achievable mechanical design
  • No high speed moving external part
  • Scalable to all sizes of ship

For theses reasons, we have undertaken at CRAIN to develop this specific kind of wind propeller. We will start the building of a prototype in 2015.

The following picture shows an artist view of a VLCC tanker (300 000 tons) that would be fitted with four wind propellers based on the suction wing concept. Size on deck is moderate and the size of the wind propeller system is suitable with shipi dimensions. Average consumption savings is about 25% and can be much higher as advantagous weather conditions are encountered.

 

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Performances

We have worked on aerodynamic and energetic aspects of such a system. This work allows us increasing significantly energetic performances of this system and there is still room for further improvements. We have been able to validate and ameliorate the performances of this system thanks to our experience in aerodynamics. Hence, we have carried out wind tunnel campaigns as well as CFD runs (Computational Fluid Dynamic). 

 

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Potential savings

Potential savings, in terms of fuel consumption, and so of polluting gaz emission, related to the use of wind propeller concept depends strongly on ship operating conditions, especially :

  • encountered weather conditions
  • average operating speed, particularly in the case of voluntary speed reduction (slow steaming)
  • ability to optimize the ship route (weather routing)

All theses parameters have to be taken into account to achieve a rigourous study of possible savings. CRAIN has develop efficient tools in order to address correctly the influence of all thoses criteria.

Studies that we have carried out so far show that savings on average fuel consumption are up to 30%, based on realistic asumptions. This forecast can be overshot in case of advantageous weather conditions.

For further information, download our paper :  Analysis of wind propulsion for cargo ships and workboats

 

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