Cemre POLAT, Doğan Burak SAYDAM, Mustafa SÖYLER, Coskun ÖZALP

İKİLİ KÜP MODELLERİNİN AKIŞ ALANINA FARKLI AÇIKLIK ORANLARINDA YERLEŞTİRİLMESİNİN AKIŞ YAPISINA ETKİSİNİN DENEYSEL OLARAK İNCELENMESİ

Küp şeklindeki cisimlerin birbiri ile konumlandırılması cisimlerin etrafındaki akış yapısından kaynaklanan akış etkileri açısından önemlidir. Cisimlerin yerleşimi faydalı rüzgâr akımı yaratabileceği gibi istenmeyen rüzgâr akımı meydan getirerek cisimlerde yapısal titreşimler ve gürültü gibi istenmeyen durumları da meydana getirebilmektedir. Bu çalışmada akrilik malzemeden, 75x75mm boyutlarında imal edilen küp cisim modelleri, aralarında farklı açıklık oranlarında (D/h = 0.5, 1 ve 2) olacak şekilde konumlandırılmıştır. D küpler arasındaki mesafeyi, h küpün kenar uzunluğunu ifade etmektedir. Kullanılan modellerin karakteristik çapına (h) ve akış hızına (V) bağlı olarak deneyler Reynolds sayısı, Re=26000’de gerçekleştirilmiştir. Parçacık Görüntüleme Hız Ölçüm Tekniği (PIV) kullanılarak anlık olarak elde edilen hız vektörleri ile anlık girdap, akım çizgisi gibi bileşenler hesaplanmış ve hesaplanan anlık verilerle de zaman ortalama hız, girdap ve türbülans istatistikleri belirlenmiştir. Çalışma sonucunda, ayrılmış akış bölgesinin D/h oranının artması ile daha geniş bir alana yayıldığı görülmektedir. D/h oranının artması ile hız bileşeninin dalgalanmalarının azaldığı, modeller arasındaki D/h oranının azalması ile iki model arasında kalan bölgede akış hızının arttığı tespit edilmiştir.

Anahtar Kelimeler:

Kübik cisimler, Akış yapısı, PIV, D/h

Experimental Investigation of The Effect of Placing Dual Cube Models in The Flow Field with Different Gap Ratios on Flow Structure

The positioning of cube-shaped objects with each other is important in terms of flow effects arising from the flow structure around the objects. The placement of the objects can create a beneficial flow regime, as well as creating undesirable wind flow and undesirable situations such as structural vibrations and noise in the objects. In this study, cube object models manufactured from acrylic material with dimensions of 75x75mm were positioned with different gap ratios (D/h = 0.5, 1 and 2) between them. D is the distance between cubes; H is the characteristic height of the cube. The experiments were carried out at Reynolds number of 26000, depending on the characteristic height (H) and flow velocity (V) of the models used. Using the Particle Imaging Velocity Measurement Technique (PIV), instantaneous velocity vectors and components such as instantaneous eddies and streamlines were calculated, and the average turbulence statistics values were determined with the instant data. As a result of the study, it is seen that the flow separation zone spreads over a wider area with the increase of the D/h ratio. It has been determined that the fluctuations of the velocity component decrease with the increase of the D/h ratio. The decrease in the D/h ratio between the models resulted increasing the velocity of the fluid.

Keywords:

Cube, Flow structure, PIV, D/h,

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