Study on Shock Waves and Hydraulic Jumps in an Inclined Rectangular Chute Contraction

• Main Authors: Chia-Jung Chang, 張家榮
• Other Authors: Chyan-deng Jan
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/05874868884215718067

博士 === 國立成功大學 === 水利及海洋工程學系碩博士班 === 96 === This study mainly aims to deliberate the hydraulic characteristics of shock waves and hydraulic jumps in inclined chute contractions by laboratory experiments. Besides, a two-dimensional numerical model was used to simulate the experimental shock waves of present study and also extended the numerical simulation for higher approach Froude numbers of shock waves. The experiments on shock waves in chute contractions were conducted by way of five bottom angles and four sidewall deflection angles. According to the experimental results, the empirical relations are proposed in this study for applicability, such as the shock angle, the sequent flow depth ratio on shock front, the dimensionless shockwave position, the decreasing rate of flow depth along chute axis, the dimensionless shockwave height and the discharge ratio of zone I (the area between two sides of shock front) to zone II (the area between shock front and sidewall). Furthermore, the numerical results show that the numerical values on longitudinal and transversal flow profiles are similar to the experimental ones. Moreover, the numerical results also validate the applicability of the proposed empirical relations, such as shock angle, the dimensionless shockwave position, and dimensionless shockwave height by experiments and extend its applicability for lager values of the approach Froude number from 3.51 to 6.06. The sequent flow area ratio relation for hydraulic jumps in chute contractions is developed with one-dimensional continuity equation and the momentum equation in this study. This developed relation can validate its applicability through verification of experimental data. Besides, some empirical relations are proposed by experiments through the experimental conditions of four bottom angles and eight sidewall deflection angles in this study, such as the empirical correction factors J and K versus bottom angles, the dimensionless hydraulic jump length, the sequent Froude number ratio, the dimensionless hydraulic jump energy loss, and the dimensionless toe location of hydraulic jump. The above-mentioned relations can validate the hydraulic parameters of hydraulic jumps for engineering applications under the experimental conditions of present study. Furthermore, the relation of critical flow condition for shock waves transferring to hydraulic jumps in chute contractions has been proposed as well. This proposed relation could be used for estimation of flow condition.