Free Energy Change of Droplet Formation in a Supersaturated Vapor

Abstract

The behavior of the pure substances during the condensation of liquid droplets in a supersaturated vapor and, the mechanism of homogeneous nucleation of vapor to liquid droplets that may occur as a result of large amplitude density fluctuations within the coexistence line in the metastable region have been investigated. The free energy change accompanying the formation of a critical water drop is calculated as a function of droplet radius for various saturation ratios on the basis of Fisher’s model. It is observed that a geometric term due to the fact that the surface of a drop relaxes to spherical shape which reduces the total entropy associated with the surface free energy, produces significant changes in total free energy change of critical droplet formation.

Keywords

• Supersaturation ratio,droplet formation,saturation density

Süperdoyumdaki Buhar İçinde Damlacık Oluşumunun Serbest Enerji Değişimi

Abstract

Süperdoymuş bir buhar içinde damlacık oluşumu sırasında saf bir numunenin davranışı ve yarı sıvı-gaz faz eğrisi altındaki kararlı bölgedeki büyük genlikli yoğunluk dalgalanmaları sonucunda buhar fazından damlacıklar oluşumu süreçleri araştırılmıştır. Fisher modeli temelinde, çeşitli doyma oranları için, kritik su damlacıklarının oluşumu esnasındaki serbest enerji değişimleri damlacık yarıçapının bir fonksiyonu olarak hesaplanmıştır. Damlacık yüzeyinin küresel şekil alması ile yüzey serbest enerjisi ile bağlantılı olan toplam entropinin azalmasını tanımlayan geometrik terimin kritik damlacık oluşumlarını tanımlayan toplam serbest enerjide anlamlı değişmelere neden olduğu gözlenmiştir.

Keywords

• Süperdoyma oranı,damlacık oluşumu,doyma yoğunluğu

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