A Numerical Study on the Collision Behavior of Droplets
نویسنده
چکیده
Numerical simulations of head-on collisions of water droplets at various Weber numbers have been performed. The Navier-Stokes equations are solved by using a finite-volume formulation on a fixed grid with a two-step projection method. Free surfaces are tracked by a technique called “volume-of-fluid”(VOF). A continuum surface force(CSF) model is used to calculate the surface tension force. Both equal-size and unequal-size droplets have been studied. The results are in agreement with experimental observations.
منابع مشابه
Statistical Modeling for Oblique Collision of Nano and Micro Droplets in Plasma Spray Processes
Spreading and coating of nano and micro droplets on solid surfaces is important in a wide variety of applications including plasma spray coating, ink jet printing, DNA synthesis and etc. In spraying processes, most of droplets collide obliquely to the surface. The purpose of this article is to study the distribution of nano and micro droplets spreading when droplets impact at an oblique a...
متن کاملParametric Study of Fuel Vapor Concentration Distribution Due to Vaporization of Fuel Droplets in Free Atmosphere
The growth of a two-phase cloud of a liquid fuel in a stagnant atmosphere is studied using computational fluid dynamic techniques. In order to predict the danger and hazard of such cloud in open atmosphere it is very important to determine the fuel concentration in the cloud, especially in the far field region from the fuel reservoir. The results show that with omission of droplets break up...
متن کاملTurbulent collision efficiency of heavy particles relevant to cloud droplets
The collision efficiency of sedimenting cloud droplets in a turbulent air flow is a key input parameter in predicting the growth of cloud droplets by collision–coalescence. In this study, turbulent collision efficiency was directly computed, using a hybrid direct numerical simulation (HDNS) approach (Ayala et al 2007 J. Comput. Phys. 225 51–73). The HDNS results show that air turbulence enhance...
متن کاملPopulation Balance Equation Modeling of Crude Oil Demulsification Considering Demulsifier: Modification of Collision Frequency Function Based on Thermodynamic Model
A theoretical model is developed to consider the effect of demulsifier agent on demulsification of water-in-crude oil emulsion. A thermodynamic approach is considered to correlate the critical micelle concentration of a demulsifier to the collision frequency function in population balance equation (PBE). Based on the proposed correlation, the collision frequency function is modified to account ...
متن کاملNumerical Simulation of Droplets Behavior of Cu-Pb Immiscible Alloys Solidifying under Magnetic Field
A model has been presented for the coarsening of the dispersed phase of liquid-liquid two-phase mixtures in Cu-Pb alloys under the effect of a high magnetic field (HMF). The numerical results show that the evolution of size distribution is the result of several factors and the diffusional growth, the collision-coagulation of the Cu-rich droplets (gravity sedimentation and Marangoni migration), ...
متن کامل