EKSENEL TÜRBİN KANATLARI ARASINDA OLUŞAN İKİNCİL AKIŞ KAYIPLARININ BARİYER UYGULANARAK AZALTILMASI

Bu çalışmada, eksenel türbin kanatlarının arasında oluşan ikincil akışların yapısı ve bu akışların neden olduğu aerodinamik kayıpların azaltılmasına yönelik bariyer uygulaması yöntemi sayısal olarak incelenmiştir. Bu amaçla, öncelikle mevcut literatür gözden geçirilmiş ve önerilen ikincil akış modelleri sunulmuştur. Çalışmada, akışkanın hareket ettiği dönen kanat kanalı modellenmiş, kanat ucu sızıntı akışı ve göbek üzerinde oluşan at nalı çevrisinin aerodinamik yapısı elde edilmiştir. İkincil akışların oluşturduğu toplam basınç kayıp katsayıları ANSYS Fluent yazılımı ile hesaplanmıştır. Aynı çalışma koşullarında olmak üzere toplam basınç kayıplarnı azaltmaya yönelik üç farklı yükseklikteki bariyer geometrisi incelenmiştir. Bariyer uygulaması ile kanat çıkış kesitlerinde toplam basınç kayıp katsayılarında azalma olduğu belirlenmiştir.

SECONDARY FLOW LOSS REDUCTION IN AXIAL TURBINE BLADES BY ENDWALL FENCE APPLICATION

In this study, it is investigated the effects of secondary flows and corresponding aerodynamic loss in axial turbine rotor numerically. To this sense, it is overviewed available literature and presented secondary flow models given by different authors. The rotor blades in which fluid flows is modeled and aerodynamic structure of tip leakage flow and horseshoe vortex are obtained. Loss mechanisms related to secondary flow and methods to reduce these losses are outlined. For same working conditions, total pressure loss is computed for three different fence height via ANSYS Fluent software. It is obtained that there is reduction of total pressure loss coefficient at blade outlet cross-section.

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