Abstract
An experimental study is carried out for dividing flow through 90° T-junction of square cross-section. The Reynolds number based on the mean velocity at the main channel and the hydraulic diameter ranges from 1.3×10^3 to 2.0×10^4. The flow rate ratio (ratios between the flow rates in branch and main channel) is set at 0.2, 0.4, 0.6 and 0.8. The loss coefficient and wall static pressure are measured to quantify the energy loss. The velocity profiles are measured by a PIV system. At laminar flow, the loss coefficient of branch channel increases rapidly with increasing the flow rate ratio. This is because the reverse flow from the main channel flows into the branch channel. In turbulent flow, the recirculation region of the main channel becomes narrow as compared with laminar flow.