It is notable to study on the fluid flow in the branched channels, because of their application in the very industrial and engineering systems. In this work, the application of the Computational experiments for understanding of the fluid behavior was studi ed in the Y-shaped channel. Here, it focuses on the Recirculation zones and length. Two types of Y-shaped channel were used, which ones named as a straight Y-shaped channel and a diagonal Y-shaped channel. From initial considerations, the Reynolds number and the angle were determined as effective parameters. Computational experiments based on the Response Surface Methodology ( as Central Composite Design) were used to predict the proposed model from Computational Fluid Dynamic data. The effect of these parameters was studied. Results show that with increasing the angle and decreasing the Reynolds number, Recirculation length decreases. However, in a diagonal Y-shaped channel, the angle is an important parameter and must be considered in studies
