Abstract
The purpose of this paper is to experimentally investigate behavior of transient jet from an L-shaped nozzle in a horizontal turbulent pipe flow. The selected Reynolds numbers are 4.24 × 103, 1.11 × 104 and 1.70 × 104 where the pipe flow is fully turbulent one. The preliminary computation is carried out for no jet injection case, and shows that the wake behind the nozzle forms within five times the nozzle inner diameter. Using the LDV measurement, the transient jet injected into a turbulent pipe flow is found to behave a similar one, for x › 50mm from the nozzle exit, to an axisymmetric free turbulent round jet whose centerline velocity ucl decreases as ucl ∼ 1/x. After the transient jet passing through a measurement point, the centerline velocities are almost identical between with and without the jet injection. In addition, this paper visualizes the transient jet to observe the jet behavior using the red food coloring.
