• T-Junction
• low side flow
• turbulent mixing
• wire mesh sensor
• thermal fatigue

The present work deals with turbulent mixing in a horizontal T-Junction, in the particular condition in which the flow rate in the side branch of the T-Junction is some orders of magnitude lower than the flow rate in the main branch of the junction.
A T-Junction facility has been constructed for the express purpose of studying, with wire mesh sensors (WMS), low side flow T-Junction mixing, in which thermal fluctuations frequencies are believed to be in the range relevant to the thermal fatigue problem. The different electrical conductivities of the mixing water streams mimics the temperature as scalar to model the thermal mixing processes.
Then, two sets of experiments are realized, to study the mixing close to the center of the T-Junction, changing some operative parameters, like the diameter and the flux ratio between the side and the main branch of the junction and the location of the sensor in the side branch.
From the cross-sectional WMS data averaged in time and the RMS (root mean square) values, we can see important characteristics of the mixing and from the amplitude spectrum of the scalar we can obtain important information about the frequency and the amplitude of the mixing fluctuations in some near the wall.