Ph.D., Professor

Education

•B.S., Mechanical Engineering, Tsinghua University

•M.S., Mechanical Engineering, Tsinghua University

•Ph.D., Mechanical and Aerospace Engineering, Princeton University

Research Areas

Combustion and Propulsion, Energy, Alternative and Surrogate Fuels, Fire Safety, Flame Dynamics, Chemical Kinetics and Mechanism Reduction, Adaptive Simulation of Multi-scale Reactive Flow

Research Profile

Environmental regulations and energy diversity produce an urgent need to develop and utilization alternative clean fuels. Alternative fuels include bio-derived fuels, such as ethanol and bio-diesel, and new fossil fuel sources, such as oil sands and oil shale. A successful design of reliable and efficient engines operating on high content bio-derived fuels or new fossil fuels strongly depends on knowledge of the combustion properties of these fuels. For example, ultra-lean premixed hydrocarbon combustion (LPC) is currently one of the most promising concepts for substantial reduction of emissions while maintaining high efficiency. This mode of combustion is operated with excess air to reduce the flame temperature to levels that virtually eliminate NOx production. However, operating at the lean flammability limit poses significant challenges with flame stability, noise, and system dynamic responses. Minor fluctuations in the fuel/air ratio, for example, can lead to flame blowout, combustion instabilities, auto-ignition and flashback, all of which strongly depends on fuel types. For our future research, the understanding of fundamental combustion properties of different alternative fuels will be a priority. Counter-flow flame and spherical flame experiments on alternative fuels will be conducted to study the flame ignition/extinction and propagation/instability, respectively. Other problems such as soot formation, flame radiation and turbulence interaction, and chemical mechanism development will be also been investigated. In addition, accompanied high fidelity multiscale modeling will be conducted to analyze/explain the experimental observations.

Professional Honors and Awards

•Chinese Government Award for Outstanding Self-financed Students Abroad, China Scholarship Council, 2009.

•Bernard Lewis Fellowship, International Combustion Institute, 2008.

•Wu Prize for Excellence, Princeton University, 2007.

Professional Activities

•International Combustion Institute, member

•American Institute of Aeronautics and Astronautics (AIAA), member

Selected Recent Publications

1.Z. Chen, M.P. Burke, Y. Ju, “On the critical flame radius and minimum ignition energy for spherical flame initiation,” Proceedings of the Combustion Institute, 33 (2011) 1219-1226.
 

2.Z. Chen, “On the extraction of laminar flame speed and Markstein length from propagating spherical flames”, Combustion and Flame, 158 (2011) 291-300.
 

3.Z. Chen, “Effects of radiation and compression on propagating spherical flames of methane/air mixtures near the lean flammability limits,” Combustion and Flame, 157 (2010) 2267-2276.
 

4.Z. Chen, X. Gou, Y. Ju, “Studies on the outwardly and inwardly propagating spherical flames with radiative loss,” Combustion Science and Technology, 182 (2010) 124-142.
 

5.Z. Chen, “Effects of hydrogen addition on the propagation of spherical methane/air flames: a computational study,” International Journal of Hydrogen Energy, 34 (2009) 6558-6567.
 

6.Z. Chen, M.P. Burke, Y. Ju, “Effects of compression and stretch on the determination of laminar flame speeds using propagating spherical flames,” Combustion Theory and Modelling, 13 (2009) 343-364.
 

7.Z. Chen, M.P. Burke, Y. Ju, “Effects of Lewis number and ignition energy on the determination of laminar flame speed using propagating spherical flames,” Proceedings of the Combustion Institute, 32 (2009) 1253-1260.
 

8.Z. Chen, Y. Ju, “Combined effects of curvature, radiation, and stretch on the extinction of premixed tubular flames,” International Journal of Heat and Mass Transfer, 51 (2008) 6118-6125.
 

9.Z. Chen, X. Qin, B. Xu, Y. Ju, F. Liu, “Studies of radiation absorption on flame speed and flammability limit of CO2 diluted methane flames at elevated pressures,” Proceedings of the Combustion Institute, 31 (2007) 2693-2700.
 

10.Z. Chen, Y. Ju, “Theoretical analysis of the evolution from ignition kernel to flame ball and planar flame,” Combustion Theory and Modelling, 11 (2007) 427-453.