Nozzle Flow Simulation by Small Disturbance Approximation and Euler Method

A coupled Eulerian-Lagrangian approach was employed to Engine Combustion Network (ECN) Spray-G simulations. The Eulerian in-nozzle flow simulation was conducted with a small plenum attached to the nozzles, and the results were fed to the Lagrangian spray simulation. For Eulerian simulation, the homogeneous relaxation model (HRM) coupled with the volume of fluid (VOF) method was used. HRM proved to be good at predicting the phase change phenomena due to vaporization mechanisms, that is, both cavitation and flash boiling. As a one-way coupling, quantities such as rate of injection (ROI), mass injected through each hole, discharge coefficient, spray plume angle and half cone angle predicted from the Eulerian simulations were used as the initial and boundary conditions for the subsequent Lagrangian spray simulations using the blob injection model. Non-flashing (Spray-G1) and flashing (Spray-G2) spray was simulated, and the results were validated quantitatively against the published data in terms of the liquid and vapor penetration lengths, and good agreements were obtained. Furthermore, the simulation predicted the liquid and gas axial velocity and sauter mean diameter for Spray-G1 condition in agreement with the droplet size and particle image velocimetry (PIV) measurements from literature.

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Underexpanded Micro-nozzle Flow Simulation with Coupled Thermal-Fluid Modeling

2007 International Conference on Thermal, Mechanical and Multi-Physics Simulation Experiments in Microelectronics and Micro-Systems. EuroSime 2007 ◽

10.1109/esime.2007.360025 ◽

2007 ◽

Author(s):

Jose Hermida Quesada ◽

Jose A. Morinigo ◽

Francisco Caballero Requena

Keyword(s):

Flow Simulation ◽

Nozzle Flow ◽

Fluid Modeling ◽

Micro Nozzle

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Effect of Ambient Pressure on the Behavior of Single-Component Fuels in a Gasoline Multi-Hole Injector

ASME 2019 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2019-7258 ◽

2019 ◽

Cited By ~ 1

Author(s):

Lorenzo Nocivelli ◽

Junhao Yan ◽

Kaushik Saha ◽

Gina M. Magnotti ◽

Chia-Fon Lee ◽

...

Keyword(s):

Ambient Pressure ◽

Light Attenuation ◽

Flow Simulation ◽

Nozzle Flow ◽

Numerical Representation ◽

Air Mixing ◽

Nominal Condition ◽

Flash Boiling ◽

Characteristic Features ◽

Attenuation Profiles

Abstract The injection characteristics of neat ethanol and pure iso-octane are studied under different ambient pressure and temperature conditions. Injection under flash-boiling conditions can enhance liquid atomization and evaporation, providing the possibility of improvement in the fuel/air mixing. These super-heated conditions often introduce phenomena that are not taken into account in the standard modeling of sprays for engine applications. The present work proposes a numerical investigation of the behavior of Engine Combustion Network’s 8-hole spray-G injector, starting at the subcooled nominal condition and reducing the ambient pressure at constant low temperature to reach the flare flash-boiling condition. To initialize the properties of the injected fuel, the flow in the nozzle is simulated with a Eulerian approach, handling the two phases with a mixture model and the phase change, due to cavitation and flash boiling, with the Homogenous Relaxation Model. A map of the mixture’s kinematic and thermal behavior is obtained at the interface between the injector and the chamber to initialize the Lagrangian simulations. A literature-based vaporization model is implemented to obtain the proper description of the characteristic features of a multi-hole spray under super-heated conditions, like plume-plume interaction. The numerical representation of the spray is validated in terms of penetration and radial spreading on DBI images, reproducing the light attenuation profiles caused by the presence of the liquid spray. Simulations show that coupled nozzle flow and spray calculations capture the spray morphology and shape better compared to calculations performed without considering the nozzle flow simulation details, especially under flare flash conditions.

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Nozzle Flow Simulation of GDi for Measuring Near-Field Spray Angle and Plume Direction

10.4271/2019-01-0280 ◽

2019 ◽

Cited By ~ 4

Author(s):

Raul Payri ◽

Jaime Gimeno ◽

Pedro Marti-Aldaravi ◽

María Martínez

Keyword(s):

Near Field ◽

Flow Simulation ◽

Spray Angle ◽

Nozzle Flow

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Calculation of Unsteady Transonic Flow by an Euler Method with Small Disturbance Boundary Conditions

41st Aerospace Sciences Meeting and Exhibit ◽

10.2514/6.2003-1267 ◽

2003 ◽

Cited By ~ 5

Author(s):

Chao Gao ◽

Shijun Luo ◽

Feng Liu ◽

David Schuster

Keyword(s):

Boundary Conditions ◽

Transonic Flow ◽

Euler Method ◽

Small Disturbance

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Numerical Analysis of Nozzle Flow and Spray Characteristics from Different Nozzles Using Diesel and Biofuel Blends

Energies ◽

10.3390/en12020281 ◽

2019 ◽

Vol 12 (2) ◽

pp. 281 ◽

Cited By ~ 8

Author(s):

M.H.H Ishak ◽

Farzad Ismail ◽

Sharzali Che Mat ◽

M.Z. Abdullah ◽

M.S. Abdul Aziz ◽

...

Keyword(s):

Aerodynamic Drag ◽

Flow Simulation ◽

Nozzle Flow ◽

Fuel Injector ◽

Discrete Phase Model ◽

Spray Cone ◽

Discrete Phase ◽

Nozzle Shape ◽

Computer Fluid Dynamics ◽

Spray Characteristic

In this paper, the discrete phase model (DPM) was introduced to study the fuel injector cavitations process and the macro spray characteristic of three different types of nozzle spray shape with diesel and hybrid biofuel blend for several injection pressures and backpressures. The three types of nozzle spray shapes used were circle, elliptical A type, and elliptical B type. The cavitations’ flows inside the injector nozzles were simulated with Computer Fluid Dynamics (CFD) simulations using the cavitations mixture approach. The effect of nozzle spray shape towards the spray characteristic of hybrid biofuel blends is analyzed and compared with the standard diesel. Furthermore, a verification and validation from both the experimental results and numerical results are also presented. The nozzle flow simulation results indicated that the fuel type did not affect the cavitation area vastly, but were more dependent on the nozzle spray shape. In addition, the spray width of the elliptical nozzle shape was higher as compared to the circular spray. Moreover, as the backpressure increased, the spray width downstream increased as well. The spray tip penetration for the elliptical nozzle shape was shorter than the circular nozzle shape due to circular nozzles having smaller nozzle widths and lesser spray cone angles. Thus, this resulted in smaller aerodynamic drag.

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