LIF Laser Scanning with pent roof illumination to Investigate Mixture Distribution in IC Engines with limited Optical Access

Welß R, Wensing M (2016)


Publication Language: English

Publication Type: Conference contribution, Conference Contribution

Publication year: 2016

Event location: Lissabon PT

URI: http://ltces.dem.ist.utl.pt/lxlaser/lxlaser2016/

Abstract

Modern  IC  engines  are  realized  with  direct  fuel  injection,  so  the  mixture  formation  takes  place  in  the  cylinder.
Optical  accessible  engines  allow  a  detailed  investigation  of  the  injection  and  mixture  formation  process.  The
measurement  technique  which  is  presented  in  this  work  is  the  tracer  based  Laser-induced  fluorescence,  which
allows to quantify the air-fuel equivalence ratio in the engine. With this technique, only a single plane, which is
illuminated by a lightsheet, is investigated. The new approach which is presented in this work is the Lightsheet
scanning technique. To realize this approach the lightsheet is shifted laterally and several planes in the cylinder can
be  investigated.  The  focus  in  this  work  is  to  estimate  the  maximal  cylinder  which  can  be  measured  with  this
principle. Additionally, this idea is combined with a modified optical setup for the lightsheet forming to illuminate
the pentroof through the glass ring without using a piston window. Different optical setups are studied to realize
the  best  possible  illumination  of  the  pentroof.  The  chosen  setup  which  was  used  finally  is  combined  with  the
lightsheet scanning setup and used for the experiments. To align the optical setup fast and reliable to the different
measurement planes, all relevant parts, lenses, mirror and camera, are mounted on electrically driven linear stages. 
The engine measurement results show the successful application of the developed method. In detail, two engine
operating points are investigated and only the water temperature is varied. The method enables the reconstruction
of any cross-sections, so that the spray targeting during the injection is shown in detail and differences between the
two  operating  points  are  identified.  The  quality  and  progress  of  the  mixture  formation  is  evaluated  by  the
uniformity index, which is calculated from every recorded plane. Additionally, the air-fuel ratio is also averaged
over every plane and displayed over the crank angle to verify the results.

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How to cite

APA:

Welß, R., & Wensing, M. (2016). LIF Laser Scanning with pent roof illumination to Investigate Mixture Distribution in IC Engines with limited Optical Access. In Proceedings of the 18th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics. Lissabon, PT.

MLA:

Welß, Richard, and Michael Wensing. "LIF Laser Scanning with pent roof illumination to Investigate Mixture Distribution in IC Engines with limited Optical Access." Proceedings of the 18th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics, Lissabon 2016.

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