[1] RMIT Univ, Sch Engn, Sir Lawrence Wackett Aerosp Res Ctr, GPO Box 2476, Melbourne, Vic 3001, Australia
[2] Univ New South Wales, Sch Mech & Mfg Engn, Sydney, NSW 2052, Australia
[3] Imperial Coll London, Dept Mech Engn, South Kensington Campus, London SW7 2AZ, England