fall diameter
1.The research result demonstrates that along with the increment of Reynolds number, the root mean square value of outer fluctuating magnitude of the external diameter in fall frequency band increases, the root mean square value of fluctuating magnitude of the external diameter in high frequency band decreses, demonstrating that the fluctuation of flexible pipe wall changes fluctuation don field of original rigid pipe, large-size eddy motion increases and small-size eddy motion decreases, this reduces energy loss and increases friction reduction effectiveness.
