Sadik KAKAÇ, Muller R. VENKATARAMAN, Anchasa PRAMUANJAROENKİJ, Isak KOTCIOGLU

Modeling of two-phase flow instabilities in convective in-tube boiling horizontal systems

Bu çalışmanın amacı, düşük frekanslı osilasyonları, bir soğutucu akışkan kullanarak, yatay bir boruda soğutucu akışkanın konveksiyonla kaynamasında elde etmektir. Drift-flux ve homojen modeller kullanılarak, süreklilik, momentum ve enerji denklemlerini nümerik olarak çözerek, sistemin sürekli rejimde basinç düşümü karakteristikleri tayin edilmektedir. Iki-fazlı akım kararsızlıkları, çesitli ısı akıları, akışkan debileri ve çıkışda orifis çaplarının bir fonksiyonu olarak elde edilmektedir. Sayısal metotla elde edilen sürekli ve zamana bağlı rejim sonuçları, deneysel sonuçlar ile karşılaştırılmış ve teori ile deneyler arasında kabul edilebilir sonuçlar elde edilmiştir.

Yatay boru içerisinde konveksiyonla kaynamalı sıstemlerde iki-fazlı akım kararsızlıklarının modellenmesi

This work aims to predict the low frequency oscillations in a horizontal in-tube boiling system using a refrigerant-11 as the working fluid. The steady state system pressure-drop characteristics are determined by a numerical solution of the governing equations as derived from the Drift-flux models. Oscillations were obtained for various heat inputs, flow rates and exit restriction diameters. Both numerical solutions of the steady-state and transient solutions obtained are compared by experimental findings and a satisfactory agreement between the theory and experiments is obtained.

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