1. Department of Mechanical Engineering, University of Genoa, Via Montallegro, 1, Genova 16145, Italy e-mail:
2. German Aerospace Center (DLR), Institute of Combustion Technology, Pfaffenwaldring 38, Stuttgart 70569, Germany e-mail:
3. National Energy Technology Laboratory (NETL), U.S. Department of Energy, 3610 Collins Ferry Road, Morgantown, WV 26507 e-mail: