Краткое описание

Visualization of secondary flow behavior were carried out for the laminar flow (Re = 81) in a sharp-edged and rounded-edged 90° T-junction with an inlet flow perpendicular to both inline outlet flows orientation with a bifurcation ratio of 0.5. Particles were added to the fluid. The fluid was salt solution for density similarity with the particles, leading to eliminate the bouyance effect. Static pressures were measured at the inlet and one of the outlet channels by a U-manometer. The result shows that the rounded edge affected the recirculation secondary flow area and position leading to the reduction of the head loss. The image of the secondary flow demonstrates that a T-junction with the rounded edge with a rounded-edge radius ratio of 0.5 had a broader bifurcation area and a smaller secondary flow occupation area in the outlet channel, as compared to the sharp edge. The decreasing head loss ratio was 51 %. At rounded-edge radius ratio of 0 up to 1.5 part of secondary flow was located in the bifurcation area and the outlet area, whereas at rounded-edge radius ratio of 2 and of 2.5 it was located completely within the bifurcation area. Changing rounded-edge radius ratio from 1.5 to 2 reduced the head loss ratio up to 49.72 %.