A new computational procedure for simulating liquid jets in crossflows with atomization is described and demonstrated. In our previous work, integral form of the conservation equations has been used to derive explicit quadratic formulas for the drop size during spray atomization in various geometries. This formula relates the drop size with the local kinetic energy state, i.e. the velocities, so that

Correct prediction of spray in automotive and aerospace engines remains a challenging task. In this work we present a numerical framework to characterize the spray, using both the large scale quantities, like mean liquid volume fractions as well as small scale structures or liquid droplets. In the limit of high Reynolds and Weber number, the drop size is expected to be much smaller that can be resolved

Identifying the regime of a liquid jet is necessary to determine the physical mechanisms causing breakup and consequently how to model the jet. Existing regime diagrams are based on a small amount of data classified by superficial visual characteristics, making these diagrams too inaccurate to reliably determine the correct regime. A more accurate regime diagram is developed using primarily a large

Droplet collisions are common to many gas-liquid systems based on the spray flows injected into a gas-vapor environment. It is customary to distinguish the roles of the pre-collision droplets in such systems, namely, a target-droplet and a projectile-droplet. As a rule, the target-droplet has a lower velocity as compared to that of the projectile-droplet or can be even stationary. The secondary atomization

The influence of cavitation effect on the diesel engine nozzle is based on the following aspects: flow and spray characteristics, cavitation erosion on the nozzle wall and pressure fluctuations of diesel fuel in the system. The first two have been extensively studied, but the research on the third one is rather limited. In this article, the synchronous acquisition, data processing system of cavitation

The impact process of fuel drops on a solid dry surface under engine relevant conditions were studied, using a numerical method based on smoothed particle hydrodynamics (SPH). The post-impingement properties (mass, velocity and location) of the splashed secondary drops were analyzed. A drop/wall interaction model was developed on the basis of the SPH simulations. Numerical results show that the mass

The present experimental study extends the Ohnesorge nomogram of liquid jet breakup regimes to viscoelastic liquids and presents a model for the jet breakup length. The experiments are carried out with water and with aqueous solutions of two different flexible polymers. The experiments rely on the visualisation of the jets for identifying the breakup mechanism and for measuring the breakup length.

The outcomes of fuel drop impact on a combustion chamber wall will affect the fuel-air mixture distribution and subsequent combustion performance of an internal combustion engine. In this paper, the process of fuel drop impact on a solid dry surface was simulated, using a numerical method based on smoothed particle hydrodynamics (SPH). This method was first validated using experimental data on the

A turbulent jet breakup model is derived using concepts from probability theory. Velocity fluctuations at the free surface are hypothesized to be the cause of turbulent jet breakup. This idea is formalized by treating the fluctuations as random variables, subject to damping from the free surface. In contrast to previous theories, this theory uses a conditional ensemble average to determine quantities

In recent decades direct numerical simulations of liquid-gas flows with interface capturing/tracking method have made great progress. But to address new configurations that contain highly deformed interfaces, a question arises about the validity of the obtained results. Usually, the only solution is to perform a mesh convergence analysis on a well-defined criteria/quantity, which is really costly.

The objective of this study was to investigate the effects of the geometric parameters of a pressure-swirl duplex nozzle (dual orifice) on the spray characteristics of Jet A-1 fuel. Two pilot nozzles with different shapes and two main nozzles with different shapes were tested. The spray characteristics were analyzed by employing laser diagnostic techniques, namely a phase Doppler particle analyzer

We consider the momentum effects on drop size and distributions during spray atomization. By adding the liquid and gas momentum analysis to conservation equations for mass and energy, we construct a formulation for determination of the spray drop size, number density, and liquid/gas velocities during spray atomization. In this approach, the aerodynamic drag is approximately parameterized by the drag

Two-dimensional axisymmetric large eddy simulation was conducted to model the sheet formation and primary breakup of gelled kerosene and gelled hydrogen peroxide in a pintle injector. This was done by varying the pintle opening distance. To simulate a hollow conical gelled hydrogen peroxide sheet from the center gap and the sheet breakup by the gelled kerosene from the annular gap, volume of fluid

Electrostatic actuation is used for real-time multiphysics feedback control of two-fluid coaxial atomization. This actuation is added to the modulation of the axial and angular momentum of the turbulent coaxial gas stream, for a total of three actuators to control atomization. We characterize the spray real-time response through optical scattering measurements of radial liquid distribution. We apply

The effect of counter electrode curvature on the onset voltage and spray angle of the electrospray in the cone-jet mode is experimentally investigated. Six counter electrodes, including a conventional flat electrode, and five curved (both concave and convex) electrodes are considered. The curvature of the curved electrodes was in the range of 10−33.3 m-1. The applied voltage, the voltage range of the