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.
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Abbreviations
- a:
-
Ellipse major axis, acceleration
- C:
-
Constant of the CSD model
- CD :
-
Drag coefficient
- C RT :
-
Breakup constant of RT model
- Cτ :
-
RT breakup time constant
- C 0 :
-
Orifice diameter
- d D :
-
Diameter after breakup
- d L :
-
Diameter of the ligament
- K :
-
Density ratio of liquid-gas
- K L :
-
Most unstable wave number of LISA model
- K RT :
-
Wave number of the RT model
- L:
-
Axial distance from the injector
- Lb :
-
Breakup length
- N :
-
Viscosity ratio of liquid-gas
- P:
-
Injection pressure
- r c :
-
Droplet radius after breakup
- t 0 :
-
Thickness of the liquid sheet at the nozzle exit
- t b :
-
Sheet thickness at the breakup length
- t s :
-
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
- g:
-
Gas properties
- l:
-
Liquid properties
- LISA:
-
LISA model
- RT:
-
Rayleigh/Taylor wave
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Park, S.W., Kim, H.J. & Lee, C.S. Numerical and experimental analysis of spray atomization characteristics of a GDI injector. KSME International Journal 17, 449–456 (2003). https://doi.org/10.1007/BF02984371
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DOI: https://doi.org/10.1007/BF02984371