Modeling Evaporating Droplets in Complex Unsteady Flows

Modeling Evaporating Droplets in Complex Unsteady Flows

In many applications, a moving fluid carries a suspension of droplets of a second phase which may change in size due to evaporation or condensation. Examples include liquid fuel drops in engines and raindrops or ice-crystals in a thunderstorm. If the number of such particles is very large, and, if further, the flow is inhomogeneous, unsteady or turbulent, it may be practically impossible to exp...

Salt stains from evaporating droplets

The study of the behavior of sessile droplets on solid substrates is not only associated with common everyday phenomena, such as the coffee stain effect, limescale deposits on our bathroom walls , but also very important in many applications such as purification of pharmaceuticals, de-icing of airplanes, inkjet printing and coating applications. In many of these processes, a phase change happen...

On the lifetimes of evaporating droplets

The complete description of the lifetime of a droplet on a solid substrate evaporating in a ‘stick–slide’ mode is obtained. The unexpectedly subtle relationship between the lifetime of such a droplet and the lifetimes of initially identical droplets evaporating in the extreme modes (namely the constant contact radius and constant contact angle modes) is described and summarised in an appropriat...

Unsteady Flows in Turbines

Dispersion of Evaporating Droplets in a Swirling Axisymmetric Jet

The effects of swirl and vaporization on droplet dispersion are investigated in the near region of a two-phase, swirling, heated jet. Simulations are based on the numerical solution of time-dependent, axisymmetric gas-phase equations.Droplets’ trajectories are tracked byusingaLagrangianapproach.Forall of the swirl cases investigated, the droplet dispersion exhibits a nonmonotonic behavior, with...