STUDY OF STREAMLINE AND EDDY CURRENT BEHAVIOR IN SUDDEN ENLARGEMENT CIRCULAR PIPE

Abstract

The steady and unsteady flow through sudden enlargement circular pipe was studied experimentally and computionally both in one and two-phase flows. In this paper, the CAD model of Computational Fluid Dynamic method was selected to investigate of properties flow distribution. The models designed in Solid Works and analyzed by exemploying Computational Fluid Dynamics (CFD) package. At the end, the streamline of model is compared with current data secondary that has been measured experimentally. Improving flow-rate and selecting an accurate turbulence model for predicting flow separation were also studied. Eddy current behavior during enlargement, maximum speed and length of circulation were calculated in detail as an initial steady state simulation. Full model of the pipe produced in an appropriate domain to look at the laminaer and turbulence behavior at the front and rear of the enlargement in different time steps. It was found that the flow-rate quality had a great influence to convergence and changed Eddy current length. In particular, it is important to have estimates of pressure drops along pipe, lift and side force characteristics at an early stage in a design. It was also determined that the pipe geometry parameters (edge, ratio of diameter, front side, inner body surface, rear end tail extension and underbody roughness) had a significant role in shifting laminar, turbulence and Eddy current behavior of the flow in pipe. Controlling the length, drag and pitching moment needs a great understanding of the fluid dynamics around the pipe.