“…Most of the researches concern the case of flow through straight pipes or rectangular ducts and are experimental (Doron and Barnea, 1996;Doron et al, 1987;Gillies et al, 2004;Kaushal and Tomita, 2003;Kaushal et al, 2005;Matousek, 2000;Shaan et al, 2000;Shook and Roco, 1991;Vlasak and Chara, 2011;Vlasak et al, 2012). However, the technical and economic burden of lab test has led some authors to study the problem by means of computational fluid dynamics (Chen et al, 2009;Lahiri and Ghanta, 2010;Lin and Ebadian, 2008;Ling et al, 2003;Xiaowei and Liejin, 2010).…”