Experimental Investigation of Turbulent Flow in Transition Duct

Abstract

An experimental study was conducted to investigate turbulent flow through from rectangular cross-sectional area to rectangular transition duct. Three kinds of channels with different length, side angle and geometrical dimensions were designed and then flow characteristic of them were all tested. The transition duct have different inlet and outlet cross-sectional areas, outlet section is double than inlet sectional area. Measurements were made at several station along the channel and at various flow-rates, Reynolds numbers ranging from 2.105 to 6.105, in which the two–dimensional mean, local velocity and pressure were measured at the x/l = 0.20, 0.40, 0.60, 0.80, 1.00 ratio, inlet by using hot wire anemometer. Based on experimental results, different flow characteristics were obtained. According to mean and local velocity and pressure drop values, each section point of the transition duct showed various values. Friction coefficient was lowered with increasing pipe length and increasing Reynolds number. Cross flows was shown in the short pipe along length at the low Reynolds.

Keywords

• transition duct
• complex turbulent flow
• secondary flow
• flow measurement