Effect of Injection Temporal Splitting on the Characteristics of Fuel-air Mixture Formation in a Common Rail Diesel Spray

Abstract

The mixture formation characteristics in a temporally split injection diesel spray were studied through a series of measurements based on the laser absorption-scattering technique (LAS), which was developed by the authors and adopted the second harmonic (532 nm) and the fourth harmonic (266 nm) of a pulsed Nd:YAG laser as the incident light, and dimethylnaphthalene (DMN) as the test fuel. By applying this technique, imaging was made of DMN sprays injected into a high- temperature (833 K) and high-pressure (4.0 MPa) constant-volume vessel by a single-hole nozzle and a common rail injection system for a direct injection (DI) diesel engine. Quantitative information of the vapour evaporation and fuel distribution was obtained, and furthermore the fuel-air mixture was characterized. The effect of injection temporal splitting on the mixture characteristics was analysed and correlated with the characteristics of NO _x formation in a DI diesel engine.

Keywords

spray diesel engine fuel injection laser diagnostic vapour concentration

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References

Tow

Pierpont

Reitz

R D

Reducing particulate and NO_x emissions by using multiple injections in a heavy duty DI diesel engine. SAE paper 940897, 1994.

Nehmer

D A

Reitz

R D

Measurement of the effect of injection rate and split injections on diesel engine soot and NO_x emissions. SAE paper 940668, 1994.

Pierpont

D A

Montgomery

D T

Reitz

R D

Reducing particulate and NO_x using multiple injections and EGR in a DI diesel engine. SAE paper 950217, 1995.

Han

Uludogan

Hampson

Reitz

Mechanism of soot and NO_x emission reduction using multiple-injection in a diesel engine. SAE paper 960633, 1996.

Felton

P G

Bracco

F V

Bardsley

On the quantitative application of exciplex fluorescence to engine sprays. SAE paper 930870, 1993.

Suzuki

Nishida

Hiroyasu

Simultaneous concentration measurement of vapour and liquid in an evaporation diesel spray. SAE paper 930863, 1993.

Zhang

Yoshizaki

Nishida

Imaging of droplets and vapour distributions in a diesel fuel spray via laser light absorption-scattering technique

Appl. Optics, 2000, 39, 6221–6229.

Zhang

Nishida

Yoshizaki

Quantitative measurement of droplets and vapour concentration distributions in diesel sprays by processing UV and visible images. SAE paper 2001–01-1294, 2001.

Zhang

Ito

Nishida

Yoshizaki

Quantitative measurement of droplets and vapour concentration distributions in a fuel spray by processing UV and visible laser images

Trans. JSAE, 2001, 32, 37–42.

10.

Zhang

A study on mixture formation in diesel sprays with split injection strategy. Dissertation, University of Hiroshima, 2001, pp. 38–40 and 65–68.

11.

Drallmeier

J A

Hydrocarbon vapour measurements in fuel sprays: A simplification of the infrared extinction technique

Appl. Optics, 1994, 33, 7175–7179.

12.

Kamimoto

Yokota

Kobayashi

A new technique for the measurement of Sauter mean diameter of droplets in unsteady dense sprays. SAE paper 890316, 1989.

13.

Zhang

Ito

Nishida

Characterization of mixture formation in split-injection diesel sprays via laser absorption-scattering (LAS) technique. SAE paper 2001–01-3498, 2001.

14.

Heywood

J B

Internal Combustion Engine Fundamentals, 1988 pp. 555–562 (McGraw-Hill, New York).