Application of laser ignition to hydrogen–air mixtures at high pressures

Abstract To optimise combustion in a wide field of applications, lasers represent attractive future alternative ignition sources, especially for internal combustion engines. Experiments were carried out in a high pressure, constant volume chamber (up to 25 MPa peak pressure and initial temperature of 473 K ). Laser induced ignition of different hydrogen–air mixtures (air/fuel equivalence ratio λ=1.8–8) was investigated, using different filling pressures (p=0.5– 4.2 MPa ), different ignition energies (pulse energy PE=1– 50 mJ ), different chamber temperatures (T=393– 473 K ) and different focal length lenses (f=60, 120 mm ). A Q-switched Nd:YAG laser at 1064 nm with a pulse duration of about 5 ns was used for ignition. An InGaAs photodetector (800– 1800 nm ) and a piezoelectric pressure transducer were used to characterise the combustion. Gas mixtures between λ=2.5 and 3.6 showed knocking combustions. With increasing initial pressures the minimum pulse energy was decreasing.

[1]  Tran X. Phuoc,et al.  Laser-induced spark ignition of CH4/air mixtures , 1999 .

[2]  S. H. Chung,et al.  Numerical simulation of front lobe formation in laser-induced spark ignition of CH4/air mixtures , 2002 .

[3]  Yuji Ikeda,et al.  Measurements of minimum ignition energy in premixed laminar methane/air flow by using laser induced spark , 2003 .

[4]  Hideaki Kobayashi,et al.  Laminar burning velocity of hydrogen-air premixed flames at elevated pressure , 2000 .

[5]  Paul D. Ronney.  Laser versus conventional ignition of flames , 1994 .

[6]  Mohamed H. Morsy,et al.  Laser-induced ignition using a conical cavity in CH4–air mixtures , 1999 .

[7]  Mohamed H. Morsy,et al.  Laser-induced multi-point ignition with a single-shot laser using two conical cavities for hydrogen/air mixture , 2003 .

[8]  C. Paillard,et al.  Laminar flame velocity determination for H2–air–He–CO2 mixtures using the spherical bomb method , 2003 .

[9]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[10]  Eli Yablonovitch,et al.  Self-phase modulation and short-pulse generation from laser-breakdown plasmas , 1974 .

[11]  Dennis R. Alexander,et al.  Laser spark ignition and combustion characteristics of methane-air mixtures , 1998 .

[12]  Jack A. Syage,et al.  Time-resolved imaging of flame kernels: Laser spark ignition of H2/O2/Ar mixtures , 1995 .

[13]  Leon J. Radziemski,et al.  Lasers-Induced Plasmas and Applications , 1989 .

[14]  P. Cho,et al.  Laser-induced two-point ignition of premixture with a single-shot laser , 2001 .

[15]  Ernst Wintner,et al.  Laser Ignition of Methane-Air Mixtures at High Pressures and Diagnostics , 2003 .

[16]  T. Phuoc.  Laser spark ignition: experimental determination of laser-induced breakdown thresholds of combustion gases , 2000 .

[17]  Ernst Wintner,et al.  Laser Ignition of Methane-Air Mixtures at High Pressures and Diagnostics , 2003 .

[18]  Paul D. Ronney,et al.  Effect of Gravity on Laminar Premixed Gas Combustion II: Ignition and Extinction Phenomena , 1985 .

[19]  Taewoo Lee,et al.  Measurements of minimum ignition energy by using laser sparks for hydrocarbon fuels in air: propane, dodecane, and jet-A fuel , 2001 .

[20]  Tran X. Phuoc,et al.  Single-point versus multi-point laser ignition: experimental measurements of combustion times and pressures , 2000 .

[21]  John B. Heywood,et al.  Two-stage ignition in HCCI combustion and HCCI control by fuels and additives , 2003 .

[22]  Jonathan Dale,et al.  Application of high energy ignition systems to engines , 1997 .