Numerical Study of Droplet Evaporation in a High-Temperature Stream

Abstract

Numerical solutions for high-temperature air flowing past water and methanol droplets and solid spheres, and superheated steam flowing past water droplets were obtained in the Reynolds number range of 10 to 100. The coupled momentum, energy, and specie continuity equations of variable thermophysical properties were solved using finite difference techniques. The numerical results of heat transfer and total drag agree well with existing experimental data. Mass transfer decreases friction drag significantly but at the same time increases pressure drag by almost an equal amount. The net effect is that the standard drag curve for solid spheres can be used for evaporating droplets provided the density is the free stream density and the viscosity of the vapor mixture is evaluated at an appropriate reference temperature and concentration. Both the mass efflux and variable properties decrease heat transfer rates to the droplets.

Высокотемпературное Испарение Капель Воды В Газовой Среде

“…Развитие теории фазовых превращений жидкостей характеризуется этапным созданием физических и ма-тематических моделей, начиная от представлений Рэнца и Маршала [1], Фукса [2] и Сполдинга [3] до Йена, Чена и Разумбулута [4,5], С.С. Кутателадзе [6], Д.В.…”

“…Ягова [7]. Модели [1][2][3][4][5][6][7] условно можно разделить на две группы ( " диффузионные" и " кинетические") по доминирующему фактору влияния на интенсивность от-рыва и последующего оттока молекул от поверхности раздела " жидкость−внешняя среда" (градиента концен-трации молекул или интенсивности нагрева поверхности фазового перехода).…”

Numerical Investigation of the Main Characteristics of Heat and Mass Transfer while Heating the Heterogeneous Water Droplet in the Hot Gases

“…The thematic justification of phase transformation of droplets and water droplet flows as well as solutes, emulsions and suspensions on its base while moving in hot gases is due to a large number of practical applications of the results (polydisperse fire extinguishing; thermal purification of water, emulsions and suspensions on its base; cleaning and processing of contaminated technological surfaces and others) [1,2]. Except droplet disintegration to typical sizes of several micrometers, using the heterogeneous droplets consisting of solid (e.g.…”

Effects of droplet interactions on droplet transport at intermediateReynolds numbers

“…15 Results from these studies are used to validate the analysis and the numerical method described in this paper. Since results were presented in the form of drag coefficients and Nusselt numbers for most of the existing studies, these integral parameters are also calculated in the present study to facilitate comparison.…”