Determination of Void Fraction by Image Processing

Abstract

Void fraction is one of the key parameters for defining the characteristics of a two phase flow. However, determination of void fraction is not easy due to changing conditions of flow and the type of fluid. In literature, there are plenty of works on determination of void fraction in two-phase flow in a pipe or channel which uses psychical parameters and properties of the system, flow and fluid. Since there are plenty number of correlations for various flow types, an experimental method has been suggested to determine the void fraction according to flow type without using any physical parameter of the flow and fluid. Image visualization methods have been applied to two-phase flow of refrigerant R600a in a circular tube. The images from high speed photography have been processed using a software developed with MATLAB Image Processing Toolbox.  The results were also compared with the well-known correlations.

Keywords

• Image processing,Two-phase flow,Void fraction

BOŞLUK ORANININ GÖRÜNTÜ İŞLEME YARDIMIYLA BULUNMASI

Abstract

Boşluk oranı iki fazlı akışta akışın karakterini tanımlamak için kullanılan önemli parametrelerden biridir. Bununla beraber değişken akış koşulları ve akış türü nedeniyle boşluk oranını belirlemek çok kolay değildir. Literatürde bir boru veya kanal içinde boşluk oranını tanımlama üzere sistem, akış ve akışkan ile ilgili parametreleri kullanan pek çok model bulunmaktadır. Farklı akış tipleri için pek çok korelasyon bulunduğu için bu çalışmada akışla ilgili herhangi bir parametre kullanmayan bir deneysel yöntem önerilmiştir.  Görüntü işleme yöntemi R600a akışkanının dairesel bir boru içerisinde iki fazlı akışına uygulanmıştır. Yüksek hızlı kamera ile elde edilen görüntüler MATLAB görüntü işleme aracını kullanarak geliştirilen bir yazılımda işlenmiştir. Ayrıca sonuçlar literatürde sık kullanılan korelasyonlarla karşılaştırılmıştır.

Keywords

• Görüntü işleme,İki fazlı akış,Boşluk oranı

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