Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2014
Öğrenci: KADİR ALİ GÜRSOY
Danışman: MEHMET METİN YAVUZ
Özet:Continuous casting of steel is accepted to operate most efficient when all its aspect are in steady state conditions. Transport rate of molten steel from tundish to the caster mold is among the parameters desired to be constant. In this process, the flow through tundish to the mold can be controlled by several flow rate control mechanism including stopper rods and slide gates. Ladle change operations in continuous casting machines result in liquid steel level changes in tundishes. During this transient event of production, the flow rate controller opening is increased to reduce the pressure drop across the opening, which helps to keep the mass flow rate constant for the reduced liquid steel level in tundish. In literature there is lack of research studies related to the influence of flow controller type on mold flow structure. The present study investigates the mold flow structure at constant throughput condition for different slide gate and stopper rod openings by utilizing computational fluid dynamic (CFD) modeling. Detailed validation of the CFD models are conducted using available experimental data and the performances of three different turbulence models, standard k-ε, realizable k-ε and k-ω SST are compared. The simulations are performed with ANSYS Fluent. The constant throughput casting operations for different slide gate and stopper rod controller openings are simulated to quantify the effect of both flow controller and their opening level on mold flow, particularly the meniscus region. The results indicate that for a slide gate controlled system, the meniscus velocities are significantly affected by the changes in the opening level. The steady state operations, specified as constant throughput casting, do not provide the same mold flow if the slide gate opening is altered. On the other hand, for the stopper rod controlled system the stopper rod opening level changes do not affect the meniscus velocities and the flow structures within the mold.