Position #1 – Applications of Laser Induced Plasma Spectroscopy to ignition of sprays

Host institution
FR - CentraleSupélec
Lab or research department name
Mechanical Engineering
Sub-domain or keywords
Plasma, Ignition, Sprays
Type of mobility
Duration (months)
From 6 to 18 months

For aeronautical applications, relight at high-altitude remains a key issue. Ignition of spray under low pressure and low temperature requires an efficient heat source, enabling ignition within few milliseconds. Due to the design of new combustion chamber to minimise pollutant emissions, new technologies are mandatory to provide energy at the region of high concentration of fuel and relatively low velocity. More fundamental studies are necessary to guide the working out of those new energy supply systems, and among others one needs new measurement techniques, that may not be required when dealing with gaseous fuel [1]. Especially, few studies have been looking at the interaction between the spark and the droplets, a key step for the successful faith of the ignition.
To study ignition of sprays, different experimental setups have been developed in the laboratory, from laminar to turbulent swirled configuration. In a previous study [2], a new measurement technique, LI2PS (Laser Induced Ignition and Plasma Spectroscopy), has been proposed, that allows not only the measurement of mean mixture fraction within a laser induced spark but also that provides a direct estimation of the scalar dissipation rate, together with the shape of the plasma. The purpose of the present project is to apply the LI2PS to study the ignition of a laminar spray (see Figure 1) and coupling this LI2PS to three dimensional measurements of droplets’ size and velocity and a planar measurement of gaseous concentration. Having access to the three dimensional representation of the spray just at the laser induced spark timing enables the prediction of the trajectory of the flame kernel. Depending on the duration of the stay, an application to a low-swirl stabilised spray configuration would be possible (see Figure 2).
This project requires both skills in optics, fluid mechanics, plasma and combustion. Especially, priority will be given to candidates familiar with ignition of sprays. A good knowledge of the plasma spectroscopy is also necessary to understand the typical uncertainties arising in the technique. Finally, experience in computing language such as Labview©, Matlab© or Python© is mandatory as many post-processing tools will be used to determine the key elements.


[1] Zimmer, L., Okai, K., Kurosawa, Y. (2007) Combined Laser Induced Ignition and Plasma Spectroscopy: Fun- damentals and Application to a Hydrogen-Air Combustor, Spectrochimica Acta Part B: Atomic Spectroscopy, 62 (12) 1484–1495.
[2] Zimmer, L. Agarwal, T. (2013) Laser-induced ignition and plasma spectroscopy in a turbulent liquid fueled combustor, Laser Ignition Conference, Yokohama, April, 23–25.


From January 2016
Maximum available positions
Laurent Zimmer <laurent.zimmer@ecp.fr>