Numerical investigation of the cooling effectiveness of a droplet impinging on a heated surface

Strotos, G; Gavaises, M; Theodorakakos, A; Bergeles, G

dc.contributor.author	Strotos, G	en
dc.contributor.author	Gavaises, M	en
dc.contributor.author	Theodorakakos, A	en
dc.contributor.author	Bergeles, G	en
dc.date.accessioned	2014-03-01T01:28:53Z
dc.date.available	2014-03-01T01:28:53Z
dc.date.issued	2008	en
dc.identifier.issn	0017-9310	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19015
dc.subject	Droplet deposition	en
dc.subject	Droplet impact	en
dc.subject	Heated wall	en
dc.subject	Vaporisation	en
dc.subject	VOF	en
dc.subject.classification	Thermodynamics	en
dc.subject.classification	Engineering, Mechanical	en
dc.subject.classification	Mechanics	en
dc.subject.other	Air	en
dc.subject.other	Computational fluid dynamics	en
dc.subject.other	Computer simulation	en
dc.subject.other	Cooling	en
dc.subject.other	Drop formation	en
dc.subject.other	Drops	en
dc.subject.other	Dynamics	en
dc.subject.other	Evaporation	en
dc.subject.other	Fluid dynamics	en
dc.subject.other	Fluid mechanics	en
dc.subject.other	Fluids	en
dc.subject.other	Forecasting	en
dc.subject.other	Heat conduction	en
dc.subject.other	Liquid phase epitaxy	en
dc.subject.other	Liquids	en
dc.subject.other	Moisture	en
dc.subject.other	Vapors	en
dc.subject.other	Walls (structural partitions)	en
dc.subject.other	Air flows	en
dc.subject.other	Atmospheric conditions	en
dc.subject.other	Cooling effectiveness	en
dc.subject.other	Coupled problems	en
dc.subject.other	Droplet deposition	en
dc.subject.other	Droplet impact	en
dc.subject.other	Droplet impinging	en
dc.subject.other	Droplet shape	en
dc.subject.other	Evaporation rate	en
dc.subject.other	Experimental data	en
dc.subject.other	Experimental observations	en
dc.subject.other	Fick's laws	en
dc.subject.other	Flow distributions	en
dc.subject.other	Flow mechanisms	en
dc.subject.other	Fluid flowing	en
dc.subject.other	Free surfaces	en
dc.subject.other	Heat conduction equation	en
dc.subject.other	Heat-transfer	en
dc.subject.other	Heated surfaces	en
dc.subject.other	Heated wall	en
dc.subject.other	Impact velocities	en
dc.subject.other	Initial stages	en
dc.subject.other	Liquid deposition	en
dc.subject.other	Liquid distributions	en
dc.subject.other	Liquid vaporization	en
dc.subject.other	Liquid-gas interfaces	en
dc.subject.other	Local temperatures	en
dc.subject.other	Model based	en
dc.subject.other	Model predictions	en
dc.subject.other	Non-equilibrium conditions	en
dc.subject.other	Numerica l results	en
dc.subject.other	Numerical investigations	en
dc.subject.other	Numerical simulations	en
dc.subject.other	Phase changes	en
dc.subject.other	Physical Properties	en
dc.subject.other	Solid walls	en
dc.subject.other	Test cases	en
dc.subject.other	Transitional period	en
dc.subject.other	Vaporisation	en
dc.subject.other	VOF	en
dc.subject.other	Water droplets	en
dc.subject.other	Phase interfaces	en
dc.title	Numerical investigation of the cooling effectiveness of a droplet impinging on a heated surface	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.ijheatmasstransfer.2008.02.036	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.ijheatmasstransfer.2008.02.036	en
heal.language	English	en
heal.publicationDate	2008	en
heal.abstract	Computational fluid dynamics numerical simulations for 2.0 mm water droplets impinging normal onto a flat heated surface under atmospheric conditions are presented and validated against experimental data. The Coupled problem of liquid and air flow,. heat transfer with the solid wall together with the liquid vaporization process from the droplet's free surface is predicted using a VOF-based methodology accounting for phase-change. The cooling of the solid wall surface, initially at 120 degrees C, is predicted by solving simultaneously with the fluid flow and evaporation processes, the heat conduction equation within the solid wall. The range of impact velocities examined was between 1.3 and 3.0 m/s while focus is given to the process during the transitional period of the initial stages of impact prior to liquid deposition. The droplet's evaporation rate is predicted using a model based oil Fick's law and considers variable physical properties which are a function of the local temperature and composition. Additionally, a kinetic theory model was used to evaluate the importance of thermal non-equilibrium conditions at the liquid-gas interface and which have been found to be negligible fertile test cases investigated. The numerical results are compared against experimental data, showing satisfactory agreement. Model predictions for the droplet shape, temperature, flow distribution and vaporised liquid distribution reveal the detailed flow mechanisms that cannot be easily obtained from the experimental observations. (c) 2008 Elsevier Ltd. All rights reserved.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	International Journal of Heat and Mass Transfer	en
dc.identifier.doi	10.1016/j.ijheatmasstransfer.2008.02.036	en
dc.identifier.isi	ISI:000259654600012	en
dc.identifier.volume	51	en
dc.identifier.issue	19-20	en
dc.identifier.spage	4728	en
dc.identifier.epage	4742	en