Numerical investigation into the evaporation dynamics of drop-on-drop collisions over heated wetting surfaces
MetadataShow full item record
The present study aims at the numerical investigation of drop-on-drop impingement over heated surfaces. Drop-on-drop impact has been found to be one of the basic processes in spray cooling applications. A two-phase solver implemented in open source CFD toolbox OpenFOAM, is used with VOF interface tracking technique which considers contact line evaporation and dynamic contact line motion. This numerical model is validated using the experimental data available in literature for single drop-hot wall interactions. The hydrodynamic behaviour (in terms of spread factor) and evaporation dynamics (in terms of input and evaporation heat transfers) of drop-on-drop impingement is compared to a single drop impact over a heated surface under similar conditions. It was found that the spread factor is higher for drop-on-drop impingement than the single droplet impact. However, high input and evaporation heat transfers were observed for the case of single droplet due to the high spread surface area-to-volume ratio. In addition, a parametric study is carried out to study the effect of some of the influencing parameters on the drop-on-drop impingement, choosing Weber number (We), Bond number (Bo), Jakob number (Ja) and Radius ratio (R * ) as parameters. Results showed that all these parameters substantially affect the spread and evaporation dynamics of the drop-on-drop collision over a heated surface. Also based on the conservation of energy principle, an analytical model is developed to find the maximum spread factor. In order to quantify the simulation heat transfer effects, a correlation for input heat transfer available in the literature is used to review the numerical findings. Both theoretical and simulation results are in good agreement with a maximum deviation of 10% in spread factor and 20% in input heat transfer prediction.
Showing items related by title, author, creator and subject.
King, Andrew (2007)This research investigation examines the thermal behaviour of single and arrays of fluid jets impinging at heated surfaces, and formulates enhancement schemes for the jet impingement heat transfer processes for high-intensity ...
Nadim, Nima; Chandratilleke, T. (2016)Jet impingement has been traditionally one of common thermal engineering solution for cooling and heating of solid surfaces, deployed in wide range of industrial applications. Flow and thermal characteristics of single-phase ...
Particle image velocimetry and infrared thermography of turbulent jet impingement on an oscillating surfaceChaugule, V.; Narayanaswamy, Ramesh; Lucey, Anthony; Narayanan, V.; Jewkes, J. (2018)© 2018 Elsevier Inc. Jet impingement is widely used for forced-convection heat transfer applications and knowledge about its flow structure and heat transfer rate on a static surface are well established. However, the ...