KSME International Journal

, Volume 17, Issue 3, pp 449–456 | Cite as

Numerical and experimental analysis of spray atomization characteristics of a GDI injector

Article
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Abstract

In this study, numerical and experimental analysis on the spray atomization characteristics of a GDI injector is performed. For numerical approach, four hybrid models that are composed of primary and secondary breakup model are considered. Concerning the primary breakup, a conical sheet disintegration model and LISA model are used. The secondary breakup models are made based on the DDB model and RT model. The global spray behavior is also visualized by the shadowgraph technique and local Sauter mean diameter and axial mean velocity are measured by using phase Doppler particle analyzer. Based on the comparison of numerical and experimental results, it is shown that good agreement is obtained in terms of spray developing process and spray tip penetration at the all hybrid models. However, the hybrid breakup models show different prediction of accuracy in the cases of local SMD and the spatial distribution of breakup.

Key Words

GDI (Gosoline Direct Injedion) Hybrid Model Atomization 

Nomenclature

a

Ellipse major axis, acceleration

C

Constant of the CSD model

CD

Drag coefficient

CRT

Breakup constant of RT model

Cτ

RT breakup time constant

C0

Orifice diameter

dD

Diameter after breakup

dL

Diameter of the ligament

K

Density ratio of liquid-gas

KL

Most unstable wave number of LISA model

KRT

Wave number of the RT model

L

Axial distance from the injector

Lb

Breakup length

N

Viscosity ratio of liquid-gas

P

Injection pressure

rc

Droplet radius after breakup

t0

Thickness of the liquid sheet at the nozzle exit

tb

Sheet thickness at the breakup length

ts

Sheet thickness

U

Total sheet velocity

y

Magnitude of drop deformation in TAB model

η0

Initial amplitude

ηb

Critical amplitude

τ

Breakup time

λ*

Wavelength for the maximum growth rate

Λ

Growth rate corresponding to maximum growth rate

ρ

Density

μ

Viscosity

Ω

Maximum growth rate

Subscripts

g

Gas properties

l

Liquid properties

LISA

LISA model

RT

Rayleigh/Taylor wave

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Copyright information

© The Korean Society of Mechanical Engineers (KSME) 2003

Authors and Affiliations

  • Sung Wook Park
    • 1
  • Hyung Jun Kim
    • 1
  • Chang Sik Lee
    • 1
  1. 1.Professor Department of Mechanical EngineeringHanyang UniversitySeoulKorea

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