Sharif Digital Repository

In this research, the numerical simulation of liquid jet ejecting for a series of elliptical orifices into gaseous phase with different aspect ratios, at Rayleigh flow regime and in a range of Weber numbers has been performed.
For simulations, the OpenFoam software was utilized, which its multiphase flow simulation solvers are based on volume of fluid (VOF) method. In order to achieve the most accurate results for axis-switching phenomenon and jet breakup length, the dynamic mesh refinement was used for all the examined cases. The results, which were validated with recent experimental and numerical works, indicate that jet breakup length raises by increasing Weber number from 20 to 300.... 

Smoothed Particle Hydrodynamics (SPH) is a numerical Lagrangian meshless method which has numerous applications in astrophysics, hydrodynamics, free-surface flows, jets and sprays formation. Atomization of continuum liquid to fine droplets or in other words, liquid breakup processes are emerged in many engineering applications such as fuel sprays inside the combustion chamber of internal combustion engines that sizes of produced sprays significantly influence the engine’s efficiency. This research is accomplished to investigate the one-phase and two-phase flows of liquid jet breakup. For this aim, an open source code called SPHysics which solves the flow field by SPH method is utilized. This... 

Numerical simulation of flow fields inside and outside of a pressure-swirl injector is considered in the present study. Injector characteristics such as the injected liquid sheet thickness, liquid sheet breakup length, and spray angle can be accurately captured via numerical simulations and used for the design optimization of an injector. The flow fields inside of a pressure-swirl injector leading to the primary atomization process outside the injector have been simulated assuming laminar flow with periodic boundary conditions using a coupled volume of fluid (VOF) and a level set model for the two phase fluid. The ANSYS Fluent commercial program is used for simulations. The computational... 

An injector is one of the most important components of the two components chemical propulsion system used in satellite control. The design of an injector is a complicated and time-consuming process and is largely dependent on laboratory data. In this study, the spray characteristics obtained from a small scale swirl injector under different operating conditions have been experimentally measured in a laboratory environment, such as the injector discharge coefficient, spray cone angle, and the distribution of droplets in the field. To calculate the discharge coefficient, the flow rate of the injector has been measured for different operating pressures. The shooting method and image processing...