Deposition of Volcanic Ash inside Gas Turbine Aeroengines
Computational Fluid Dynamics
The eruption of Eyjafjallajokull in Iceland in 2010 cost the airline industry hundreds of millions of pounds when the Civil Aviation Authority imposed a blanket ban on flights across Europe. These costs stimulated a renewed interest into the effects of volcanic ash deposition in gas turbine aeroengines. An international consortium of industrial and academic partners including Double Precision Consultancy, Easyjet, Rolls Royce and Cambridge University has since been established. More details on this consortium and current results can be found at http://www.ccg.msm.cam.ac.uk/provida/overview.
One of the main objectives of the project is to identify the parameters that promote the deposition of volcanic ash on both static and rotating components. These include the particle size distribution, the relative proportion of crystalline and amorphous phases, glass transition temperatures, particle trajectories, particle velocities and particle temperature histories.
These parameters and their importance are being assessed using a combination of experimental techniques (including high speed video), computational fluid dynamics modelling and full-scale engine tests.
High speed video images of volcanic ash pellets (at temperatures >1000 deg.C) striking static targets can be found in the video gallery. These videos are being used to more fully understand the high temperature dynamic behaviour of volcanic ashes by correllation with deposition rate experiments being conducted in the Gordon Laboratory at Cambridge University. More information can be found in our more comprehensive feature article here.