Numerical CFD study on the frictional drag reduction using air lubrication

Student thesis: Master thesis (including HD thesis)

  • Jacob Bjørn Helmers Ottosen
4. term, Energy Engineering, Master (Master Programme)
In this study a series of multi-phase Large Eddy Simulations with the Volume Of Fluid approach are made to analyse the use of air lubrication to reduce the drag on a ship by injecting air bubbles underneath the hull. The multi-phase simulations are initialised with a turbulent velocity profile obtained from simulations with a single-phase computational model, which is validated against theory, by comparing the turbulent boundary layer with the law of the wall. In the multi-phase simulations, the air volume fraction is varied from 14 - 50%. In the case with an air volume fraction of 14% a reduction in wall shear stress of 20 - 40% is seen. In the other cases with an air volume fraction from 27 - 50% a reduction of 40 - 60% in the wall shear stress is seen compared to the values using the single-phase model.
SpecialisationThermal Energy and Process Engineering
Publication date30 May 2022
Number of pages73
External collaboratorAlfa Laval Aalborg A/S
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Information group
ID: 471631166