Transportation of megawatt millijoule laser pulses via optical fibers?

Open Physics ◽  
2010 ◽  
Vol 8 (2) ◽  
Author(s):  
Johannes Tauer ◽  
Heinrich Kofler ◽  
Elisabeth Schwarz ◽  
Ernst Wintner
Keyword(s):  
Laser Beam ◽  
Optical Fibers ◽  
Internal Combustion Engines ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Pollutant Emissions ◽  
Laser Ignition ◽  
Combustion Engines ◽  
Future Concepts ◽  
Pulsed Laser Beam

AbstractLaser ignition is considered to be one of the most promising future concepts for internal combustion engines. It combines the legally required reduction of pollutant emissions and higher engine efficiencies. The igniting plasma is generated by a focused pulsed laser beam. Having pulse durations of a few nanoseconds, the pulse energy E p for reliable ignition amounts to the order of 10 mJ. Different methods of laser ignition with an emphasis on fiber-based systems will be discussed and evaluated.

Review of Laser Ignition for Methane-Air Mixtures

2015 ◽  
Vol 727-728 ◽  
pp. 592-596
Author(s):  
Hong Tao Wang ◽  
Cang Su Xu
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Pollutant Emissions ◽  
Laser Ignition ◽  
Combustion Engines ◽  
Ignition System ◽  
Spark Plug ◽  
Induced Ignition ◽  
Ignition And Combustion ◽  
Promising Development

Reducing vehicle pollutant emissions and fuel consumption is becoming more and more important challenges, while lean-burning are a promising development. However, lean-burning may leads to other problems including combustion instability and incomplete combustion. Recently, laser ignition system has become an attractive field of research in order to replace the conventional spark plug ignition systems in the internal combustion engines to solve problem above. Moreover, methane was regarded as very promising fuel. Therefore, the objective of this article is to review the ignition and combustion characteristics of methane-air mixtures by laser-induced ignition.

A phenomenological model for the description of unburned hydrocarbons emission in ultra-lean engines

2021 ◽  
pp. 146808742110050
Author(s):  
Enrica Malfi ◽  
Vincenzo De Bellis ◽  
Fabio Bozza ◽  
Alberto Cafari ◽  
Gennaro Caputo ◽  
...  
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Pollutant Emissions ◽  
Average Error ◽  
Combustion Engines ◽  
Nitric Oxides ◽  
Lean Burn ◽  
Fuel Charge ◽  
Unburned Hydrocarbons ◽  
Model Reliability

The adoption of lean-burn concepts for internal combustion engines working with a homogenous air/fuel charge is under development as a path to simultaneously improve thermal efficiency, fuel consumption, nitric oxides, and carbon monoxide emissions. This technology may lead to a relevant emission of unburned hydrocarbons (uHC) compared to a stoichiometric engine. The uHC sources are various and the relative importance varies according to fuel characteristics, engine operating point, and some geometrical details of the combustion chamber. This concern becomes even more relevant in the case of engines supplied with natural gas since the methane has a global warming potential much greater than the other major pollutant emissions. In this work, a simulation model describing the main mechanisms for uHC formation is proposed. The model describes uHC production from crevices and flame wall quenching, also considering the post-oxidation. The uHC model is implemented in commercial software (GT-Power) under the form of “user routine”. It is validated with reference to two large bore engines, whose bores are 31 and 46 cm (engines named accordingly W31 and W46). Both engines are fueled with natural gas and operated with lean mixtures (λ > 2), but with different ignition modalities (pre-chamber device or dual fuel mode). The engines under study are preliminarily schematized in the 1D simulation tool. The consistency of 1D engine schematizations is verified against the experimental data of BMEP, air flow rate, and turbocharger rotational speed over a load sweep. Then, the uHC model is validated against the engine-out measurements. The averaged uHC predictions highlight an average error of 7% and 10 % for W31 and W46 engines, respectively. The uHC model reliability is evidenced by the lack of need for a case-dependent adjustment of its tuning constants, also in presence of relevant variations of both engine load and ring pack design.

High precision balanced mode polarimetry with a pulsed laser beam

1995 ◽  
Vol 119 (3-4) ◽  
pp. 403-414 ◽  
Author(s):  
M. Bouchiat ◽  
D. Chauvat ◽  
J. Guéna ◽  
Ph. Jacquier ◽  
M. Lintz ◽  
...  
Keyword(s):  
Laser Beam ◽  
High Precision ◽  
Pulsed Laser ◽  
Pulsed Laser Beam

Comparative Study on Pulsed Laser Welding Strategies for Contacting Lithium-Ion Batteries

2016 ◽  
Vol 1140 ◽  
pp. 312-319 ◽  
Author(s):  
Patrick Schmitz
Keyword(s):  
Laser Beam ◽  
Comparative Study ◽  
Weld Seam ◽  
Laser Beam Welding ◽  
Pulsed Laser ◽  
Pulsed Laser Beam Welding ◽  
Joining Process ◽  
Suitable Process ◽  
Pulsed Laser Beam ◽  
Battery Cells

The transition towards renewable energy implicates more decentralized and time-dependent ways of energy generation. In order to deal with the resulting fluctuation in energy supply, local storage systems are necessary. Larger systems may consist of thousands of battery cells. Therefore, the reliable interconnection between the individual battery cells is the basic prerequisite for the production of these systems. It has been demonstrated that laser beam welding is a suitable process for the contacting of batteries. However, due to the high requirements regarding the heat input and the reproducibility of the joining process, further investigations are necessary. Within this work, experiments on pulsed laser beam welding of nickel-plated DC04 steel were conducted. Four different pulsed welding strategies were analyzed in a preliminary study in order to develop a method for obtaining suitable process parameters while reducing the amount of free parameters. Subsequently, a comparative study between the rectangular pulse, the shaped pulse, the spike pulse and the sloping pulse was carried out. The weld seam properties as well as the electrical and the mechanical properties of the connection joints were evaluated. The results presented in this paper indicate a high eligibility of pulsed laser beam welding as a joining process for the connection of battery cells. For all analyzed pulsed welding strategies a homogeneous weld seam without full penetration was observed. Similar electrical resistances for all strategies were measured despite the comparatively small total joint area for the discretely pulsed weld seams.

Detector Array for Measuring Temporal-Spatial Distribution of High-Repetition-Rate Pulsed Laser Beam Profile

2013 ◽  
Vol 40 (6) ◽  
pp. 0608003
Author(s):  
冯国斌 Feng Guobin ◽  
王振宝 Wang Zhenbao ◽  
冯刚 Feng Gang ◽  
杨鹏翎 Yang Pengling ◽  
王群书 Wang Qunshu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Laser Beam ◽  
Repetition Rate ◽  
Pulsed Laser ◽  
High Repetition Rate ◽  
Beam Profile ◽  
Detector Array ◽  
Laser Beam Profile ◽  
High Repetition ◽  
Pulsed Laser Beam
Sign in / Sign up

Export Citation Format

Share Document