1. Center for Combustion Energy, Tsinghua University, Beijing 100084, China
2. Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
3. Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
4. Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA