TY - JOUR ID - 3893 TI - Investigation of Flow Characteristics and Pressure Parameters of Free and Submerged Hydraulic Jumps in USBR Stilling Basins JO - Amirkabir Journal of Civil Engineering JA - CEEJ LA - en SN - 2588-297X AU - Mousavi, Seyed Nasrollah AU - Davood, Farsadizadeh AU - Salmasi, Farzin AU - Hosseinzadeh Dalir, Ali AD - Hydraulic Lab Expert, Water engineering Department, Tabriz University, Iran AD - Prof., Dept. of Water Eng., Faculty of Agric., Univ. of Tabriz, Iran AD - Assoc. Prof., Dept. of Water Eng., Faculty of Agric., Univ. of Tabriz, Iran AD - Dept. of Water Eng., Faculty of Agric., Univ. of Tabriz, Iran Y1 - 2021 PY - 2021 VL - 53 IS - 10 SP - 4125 EP - 4142 KW - Ogee spillway KW - pressure coefficients KW - standard deviation of pressure fluctuations KW - submergence degree KW - USBR stilling basin DO - 10.22060/ceej.2020.17791.6676 N2 - In this study, flow characteristics and pressure parameters of hydraulic jumps have been investigated in a laboratory flume. The results for different incident Froude numbers (Fr1), at the downstream of an Ogee spillway on a typified USBR II stilling basin bed were compared with the USBR Type I basins. Dimensions of the Ogee spillway and stilling basin were designed according to the USBR criteria. The pressure data of the points on the basin bed were recorded using pressure transmitters with 20 Hz frequency. Experimental parameters, including flow depths and velocities at the beginning and endpoint of free jumps (Y1, Y2, V1 and V2), and submerged jumps (Y3, Yt, V3 and Vt) were measured. In the present study, dimensionless parameters of energy dissipation efficiency (εt), mean pressure head (Ψ*X), the standard deviation of pressure fluctuations (Φ*X), maximum positive pressure fluctuation coefficient (CP+), maximum negative pressure fluctuation coefficient (CP‒), total pressure fluctuation coefficient (CP) and skewness coefficient (Ad) were investigated. Pressure parameters are dependent on Fr1, the dimensionless position (Γ*X), and the submergence degree (S). The results showed that by reducing the Fr1 values, the εt parameter decreases. The Φ*Xmax value in the USBR Type II basin decreases around 30% compared to the Type I basins in free jumps. The reduction of Φ*Xmax values in the submerged jump with S=1.4 is about 29% than free jumps. The CP+max and |CP‒|max coefficients in the submerged jump with S=1.4 in comparison with free jumps decrease about 15 and 17%, respectively. UR - https://ceej.aut.ac.ir/article_3893.html L1 - https://ceej.aut.ac.ir/article_3893_1e1ef99652375149e906097016043ede.pdf ER -