1. Laser-assisted homogeneous charge ignition in a constant volume combustion chamber
- Author
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Henrich Kofler, Ernst Wintner, Avinash Kumar Agarwal, Martin Weinrotter, and Dhananjay Kumar Srivastava
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Homogeneous charge compression ignition ,Laser ignition ,Exhaust gas ,Mechanics ,Combustion ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Ignition system ,Internal combustion engine ,Physics::Plasma Physics ,law ,Exhaust gas recirculation ,Physics::Chemical Physics ,Electrical and Electronic Engineering ,Combustion chamber ,business - Abstract
Homogeneous charge compression ignition (HCCI) is a very promising future combustion concept for internal combustion engines. There are several technical difficulties associated with this concept, and precisely controlling the start of auto-ignition is the most prominent of them. In this paper, a novel concept to control the start of auto-ignition is presented. The concept is based on the fact that most HCCI engines are operated with high exhaust gas recirculation (EGR) rates in order to slow-down the fast combustion processes. Recirculated exhaust gas contains combustion products including moisture, which has a relative peak of the absorption coefficient around 3 μm. These water molecules absorb the incident erbium laser radiations ( λ =2.79 μm) and get heated up to expedite ignition. In the present experimental work, auto-ignition conditions are locally attained in an experimental constant volume combustion chamber under simulated EGR conditions. Taking advantage of this feature, the time when the mixture is thought to “auto-ignite” could be adjusted/controlled by the laser pulse width optimisation, followed by its resonant absorption by water molecules present in recirculated exhaust gas.
- Published
- 2009