This document discusses laser ignition systems as an alternative to spark plug ignition in internal combustion engines. It begins with an introduction explaining the limitations of spark plugs and benefits of laser ignition. It then defines what a laser is and describes different types. The document outlines how laser ignition systems work, including focusing the laser beam through a lens to ignite fuel. Advantages include precise ignition timing and ability to ignite leaner mixtures. Disadvantages are currently high costs and lack of commercial systems. In conclusion, laser ignition has potential to increase efficiency but requires further development for widespread use.

1. Work Under the Guidance of
SHERYAS P.S
Assistant Professor
Department Of Mechanical Engineering
K N S Institute of Technology, Bangalore:-560064

2. Contents
• Introduction
• What is laser?
• Type of lasers
• Battery ignition system
• Laser ignition system
• Advantages of laser ignition system
• Disadvantages of laser ignition system
• Conclusion
• References

3. INTRODUCTION
• Two main aspects of engine performance are fuel economy and exhaust gas
emissions.
• New engines are becoming increasingly complex, with advanced combustion
mechanisms that burn an increasing variety of fuels to meet future goals on
performance, fuel economy and emissions.
• The spark plug has remained largely unchanged since its invention, yet its poor
ability to ignite highly dilute air-fuel mixtures limits the potential for improving
combustion efficiency.
• Spark ignition (SI) also restricts engine design, particularly in new engines, since
the spark position is fixed by the cylinder head location of the plug, and the
protruding electrode disturbs the cylinder geometry and may quench the
combustion effiency.

4. Continued….
• So, to counter these limitations an alternative is required one of the alternative is the
laser ignition system (LIS).
• Compared to Spark ignition a LIS could prove to be better and help us increase
engine efficiency.

5. WHAT IS LASER?
• The term ‘laser’ is stands for Light Amplification by Stimulated Emission of Radiation.
• A laser is a device that emits light through a process of optical amplification based on
the stimulated emission of electromagnetic radiation.

6. Types of Lasers
• Gas
• A Helium-Neon (HeNe) used mostly for holograms such as laser printing.
• Solid-state
• Uses a gain medium that is a solid (rather than a liquid medium as in dye or gas
lasers). Used as weapon(ruby crystal)
• Semiconductor
• Also known as laser diodes, a semiconductor laser is one where the active medium is
a semiconductor similar to that found in a light-emitting diode.
• Applications include telecommunication and medicine

7. Standard Spark Plug Ignition in an IC Engine
• Current internal combustion gasoline engines use spark plugs to ignite the air/fuel
mixture in each cylinder of a SI engine(located at the top of the combustion
chamber).

8. Laser Ignition System for an IC Engine
• By tightly focusing the beam from a high-power pulse laser to form a combustion-
initiating spark in flammable mixtures including those used in engines, we
accomplish what is called laser ignition.

9. • The laser beam is passed through a convex lens, this convex lens diverge the
beam and make it immensely strong and sufficient enough to start combustion at
that point. Hence the fuel is ignited, at the focal point, with the mechanism
shown above. The focal point is adjusted where the ignition is required to have.

10. Combustion chamber window
• Core component of laser ignition system.
• Burning free effect occurs
• Singular window test show that optical window can be used
efficiently for 1000hrs

11. Supply Of Laser From Source To
Cylinder

12. Laser Incident Angle

13. Continued…
1. Laser ignition encompasses the nanosecond domain of the laser pulse
itself to the duration of the entire combustion lasting several hundreds of
milliseconds.
2. The laser energy is deposited in a few nanoseconds which leads to a
shock wave generation. In the first milliseconds an ignition delay can be
observed which has a duration between 5 – 100 ms depending on the
mixture.
3. Combustion can last between 100 ms up to several seconds again
depending on the gas mixture, initial pressure, pulse energy, plasma size,
position of the plasma in the combustion bomb and initial temperature.

14. Advantages of Laser ignition system
• Absence of quenching effects by the spark plug electrodes.
• Ignition of leaner mixtures than with the spark plug => lower
combustion temperatures => less nox emissions.
• High load/ignition pressures possible => increase in efficiency.
• Precise ignition timing possible.

15. • No erosion effects as in the case of the spark plugs => lifetime of a
laser ignition system expected to be significantly longer than that of
a spark plug.
• Shorter ignition delay time and shorter combustion time.
Continued…..

16. Disadvantages of laser ignition
Despite the advantages of the system there are a couple of
disadvantages of laser ignition:
• High system costs
• Concept proven, but no commercial system available yet.

17. Conclusion
• The applicability of a laser-induced ignition system on petrol engine has
been proven by many experiments conducted around the world.
• Significant reductions in fuel consumption as well as reductions of
exhaust gases show the potential of the laser ignition process.
• At present, a laser ignition plug is very expensive compared to a
standard electrical spark plug ignition system and it is no where near
ready for deployment. But the potential and advantages certainly make
the laser ignition more attractive in many practical applications.

18. Reference
1. Lackner, M., Winter, F., What is ignition? Combustion File 256, IFRF
Online Combustion Handbook, ISSN 1607-9116, International Flame
Research Foundation, Ijmuiden, The Netherlands, (2004).
2. H. Kopecek, M. Lackner, F. Winter, E. Wintner, Laser ignition of methane
air mixtures at pressures up to 4 MPa, Journal of Laser Physics 13 (11),
1365 (2003).
3. Kopecek, H., Lackner, M., Wintner, E., Winter, F., Laser-Stimulated
Ignition in a
4. Homogeneous Charge Compression Ignition Engine, SAE 2004 World
Congress, paper No 2004-01-0937, Detroit, MI, USA (2004).
5. J. D. Dale, M. D. Checkel, P. R. Smy, Application of High Energy Ignition
Systems to Engines, Prog. Energy Combust. Sci. 23, 379-398 (1997).

19. THANK YOU