Optical Investigation of Mixture Formation in a Small Bore DISI Engine by Laser Induced Exciplex Fluorescence (LIEF)

2019 ◽  
Author(s):  
Alexander Pauls ◽  
Peter Eilts
Keyword(s):  
Optical Investigation ◽  
Mixture Formation ◽  
Exciplex Fluorescence

Optical Investigation of HCCI Two-Stage Ignition Using Multiple Injection of Synthetic Fuels

2005 ◽  
Author(s):  
Thaddaeus Delebinski ◽  
Peter Eckert ◽  
Guenter P. Merker
Keyword(s):  
Cfd Simulation ◽  
Hole Injection ◽  
Injection System ◽  
Optical Investigation ◽  
Multiple Injection ◽  
Synthetic Fuels ◽  
Mixture Formation ◽  
Two Stage ◽  
Injection Strategy ◽  
Multiple Injection Strategy

Different synthetic fuels have been investigated within a variety of optical experiments at a rapid compression machine using diverse optical set-ups. The experiments have been carried out to determine the fuel requirements for good homogenisation and a controlled ignition and heat release for HCCI combustion. A directly actuated piezo injection system, which allows a flexible multiple injection strategy has been used to inject the fuel at different times during the compression stroke. Mie-scatter and Schlieren optics have been applied to investigate the different behaviour of the synthetic fuels concerning evaporation and mixture formation. The auto ignition behaviour of the different fuels has been investigated using an intensified relay optics and combustion chamber probes utilising the two-colour-method and a photo multiplier analysis systems. A multiple injection strategy and a 13 hole injection nozzle for HCCI operation mode with diesel-like fuels have been designed and optimised using CFD simulation prior to the experimental work. The experimental results using synthetic fuels will then be used to verify advanced 3D CFD models for multi component fuels and their behaviour concerning mixture formation and HCCI two-stage ignition.

ANALYSIS OF THE POSSIBILITIES OF REGULATING THE PROCESS OF MIXTURE FORMATION IN MICROJET BURNERS WITH CYLINDRICAL FLAME STABILIZERS

2017 ◽  
Author(s):  
Nataliia Fialko ◽  
◽  
Viktor Prokopov ◽  
Julii Sherenkovskiy ◽  
Oleksandra Tymoshchenko ◽  
...  
Keyword(s):  
Mixture Formation

A Rheo-optical Investigation into the Viscoelastic Moduli of Acidified Milk Gel

1999 ◽  
Vol 9 (6) ◽  
pp. 246-253 ◽  
Author(s):  
E. O. Arikainen ◽  
J. C. Earnshaw ◽  
A. Wehling ◽  
E. Waghorne
Keyword(s):  
Correlation Function ◽  
Mean Square Displacement ◽  
Slow Motion ◽  
Casein Micelle ◽  
Optical Investigation ◽  
Viscoelastic Moduli ◽  
Decay Times ◽  
Delay Times ◽  
Intensity Correlation Function ◽  
Viscoelastic Modulus

Abstract Diffusing wave spectroscopy (DWS) in the backscattering geometry was employed to observe the evolution of the intensity correlation function during the acidification of skimmed milk by gluconic-δ-lactone (GDL). At the stage when the formation of casein particle gel is largely complete the correlation function at shorter decay times reveals the local structural arrest of the casein micelles, whereas at longer delay times it illustrates the hindered slow motion of casein micelle aggregates. We use the principles of the approach suggested by Mason, Gang and Weitz, linking the optically measured mean square displacement, <Δr2(t)>, of the microscopic particles in a dense colloid to its viscoelastic properties, to provide an estimate of the frequency dependent viscoelastic modulus of the acidified milk gel (AMG). We compare the viscoelastic moduli measured by the conventional mechanical rheometry with the optically measured ones. The results of the two different experimental methods are found to be in reasonable agreement.

scholarly journals Optical Investigation of a Partial Fuel Stratification Strategy to Stabilize Overall Lean Operation of a DISI Engine Fueled with Gasoline and E30

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 396
Author(s):  
Cinzia Tornatore ◽  
Magnus Sjöberg
Keyword(s):  
Volume Fraction ◽  
Direct Injection ◽  
Combustion Process ◽  
Pilot Injection ◽  
Optical Investigation ◽  
Flame Kernel ◽  
Lean Combustion ◽  
Fuel Stratification ◽  
Spark Plug ◽  
Initial Flame

This paper offers new insights into a partial fuel stratification (PFS) combustion strategy that has proven to be effective at stabilizing overall lean combustion in direct injection spark ignition engines. To this aim, high spatial and temporal resolution optical diagnostics were applied in an optically accessible engine working in PFS mode for two fuels and two different durations of pilot injection at the time of spark: 210 µs and 330 µs for E30 (gasoline blended with ethanol by 30% volume fraction) and gasoline, respectively. In both conditions, early injections during the intake stroke were used to generate a well-mixed lean background. The results were compared to rich, stoichiometric and lean well-mixed combustion with different spark timings. In the PFS combustion process, it was possible to detect a non-spherical and highly wrinkled blue flame, coupled with yellow diffusive flames due to the combustion of rich zones near the spark plug. The initial flame spread for both PFS cases was faster compared to any of the well-mixed cases (lean, stoichiometric and rich), suggesting that the flame propagation for PFS is enhanced by both enrichment and enhanced local turbulence caused by the pilot injection. Different spray evolutions for the two pilot injection durations were found to strongly influence the flame kernel inception and propagation. PFS with pilot durations of 210 µs and 330 µs showed some differences in terms of shapes of the flame front and in terms of extension of diffusive flames. Yet, both cases were highly repeatable.

Optical investigation on tri-layers MoS2 thin film

2020 ◽  
Author(s):  
Chandrabhan Dohare ◽  
Premlata Yadav ◽  
S. Ghosh
Keyword(s):  
Thin Film ◽  
Optical Investigation
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