Analysis of 3-D jet scour

• Main Author: Shue, Chin Liat.
• Other Authors: Lim Siow Yong
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Environmental engineering
• Online Access: http://hdl.handle.net/10356/52759
• Institution: Nanyang Technological University

Researchers have done studies on scour hole formation by culvert outlet over the years. A compendium of scour profile data has been collected by researchers over the past 50 years. This study investigates the correlation between various parameters that occurs during scouring process to the resultant scour hole profile. Parameters in the compiled data set are categorized into three main groups, namely, the characteristic of the water stream, the channel shape and dimension, and the characteristic of sediment bed materials. These available parameters are used to predict the resultant scour hole profile; the maximum equilibrium scour depth (dse), maximum equilibrium scour length (Lse), maximum scour equilibrium scour width (Wse) and the scour volume at equilibrium (Vse) respectively. Dimensional analysis was conducted to simplify the parameters under consideration. Buckingham Π Theorem is utilized in the dimensional analysis. Dimensionless terms obtained from the dimensional analysis were used to establish a set of scour hole prediction models. Subsequently, Multiple Regression was conducted on the dimensionless terms to obtain relevant coefficients for proposed equation models. The accuracy of each equation model in predicting scour hole profile was analyzed by the goodness of fit test. Statistical value such as the R2 value was used to measure the goodness of fit. Thereafter, the most suitable equations for each of the equilibrium scour hole characteristics are proposed. The study underlines the importance of the Densimetric Froude Number (F0) on the resultant scour hole profile. It is also essential to separate the compiled data set into “Fully Submerged” and “Unsubmerged” condition for analysis. The effect of sediment bed materials, namely the median diameter of sediment bed material and the geometric standard deviation of bed sediment, are also prominent on the scour hole profile.