TY - JOUR ID - 678 TI - Pressure Fluctuations in Hydraulic Jump Investigation of Stilling Basin at Sudden Expansion JO - Amirkabir Journal of Civil Engineering JA - CEEJ LA - en SN - 2588-297X AU - Karimi1, M. AU - Musavi Jahromi, S.H. AU - Shafai-Bajestan, M. AD - Student, Faculty of Water Science Engineering, Shahid Chamran University, Ahvaz, Iran Y1 - 2017 PY - 2017 VL - 49 IS - 2 SP - 263 EP - 272 KW - Pressure fluctuations KW - Spatial hydraulic jump KW - Sudden expansion KW - Stilling basin DO - 10.22060/ceej.2016.678 N2 - The hydraulic jump in the stilling basin can be considered macroscopically as a time-averaged steady, abruptly varied flow characterized by a free surface discontinuity and the formation of strong vortex that generates macro turbulent fluctuations.This paper are discussed the characteristics of pressure fluctuations in spatial hydraulic jumps with sudden expansion stilling basin. The effects of the channel expansion ratio and inflow condition on the dimensionless standard deviation of pressure fluctuations (cp') and extreme pressure fluctuations (Cp+, Cp-) in the hydraulic jump were examined. In this study many tests were conducted in a relatively large flume size of 0.8 meter wide and 12 meter length. data were presented for Froude numbers from 2.5 to 9.5 and channel expansions ratio (B1/B2) was 0.33, 0.5, 0.67 and 1. Pressure data were recorded by means of pressure transducers systems. A sampling frequency of 40 Hz was selected. The results show that the dimensionless standard deviation of pressure fluctuations and extreme pressure fluctuations of the hydraulic jump are dependent on the inflow Froude number and position from the toe of the jump. Fluctuating pressure at the position of about (10-30)Y1, can reach the maximal value. And indicates that the sudden expansion at the hydraulic jump decreases pressure fluctuations. The dimensionless standard deviation of pressure fluctuations (Cp') decreases on the order 43%, 38% and 19% for expansions ratio β = 0.33 , 0.5 and 0.7, respectively compared with classic jump. UR - https://ceej.aut.ac.ir/article_678.html L1 - https://ceej.aut.ac.ir/article_678_9709701bb5321b1c85c5024d18759e0e.pdf ER -