Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : June 16, 2016 - June 17, 2016
Thermal fatigue cracking may initiate at a tee pipe in plants where high and low temperature fluids flow in. The thermal stress fluctuation is caused by the wall temperature fluctuation due to heat transfer of the fluid temperature fluctuation near the wall. In order to elucidate the flow phenomena at a mixing tee pipe to cause temperature fluctuation, a visualization experiment of the flow in mixing section was conducted using a rectangular test section made of acrylic. As a result, the flow pattern was classified by momentum ratio MR of the main and branch pipes, and it changed from wall jet to deflecting jet on MR = 3.70, and from deflecting jet to impinging jet on MR = 0.64. The jet flow from the branch pipe is swaying at a period of from about 5 s to 10 s. The relationship between the periods of fluctuation and MR was investigated. The period decreased as MR increased.
