A hydraulic model test for ￢-type groynes (with “￢” shape) was conducted to analyze the flow characteristics around these groynes. The results of the model tests are expected to be used as fundamental information ...A hydraulic model test for ￢-type groynes (with “￢” shape) was conducted to analyze the flow characteristics around these groynes. The results of the model tests are expected to be used as fundamental information in designing the ￢-type groyne constructed in the field. Main hydraulic factors such as velocity and thalweg line changes in the main channel and separation area were analyzed in this study. The thalweg line is a stream line where the maximum velocity occurs, whereas the separation area is the boundary between the main flow and the recirculation zone. Model tests with 5 different arm lengths of the ￢-type groynes were conducted by changing the velocity. The LSPIV (Large-Scale Particle Image Velocimetry) technique was used to measure and analyze flow variation around the ￢-type groynes. The velocity in the main channel measured to be increased by 1.5 times. The velocity variation on groyne arm length is little. The width of the thalweg lines (TCL) was changed to 55 - 57% of the channel width. The Froude number did not affect the thalweg line (TCL) and separation line (Sh) changes, however.展开更多
文摘A hydraulic model test for ￢-type groynes (with “￢” shape) was conducted to analyze the flow characteristics around these groynes. The results of the model tests are expected to be used as fundamental information in designing the ￢-type groyne constructed in the field. Main hydraulic factors such as velocity and thalweg line changes in the main channel and separation area were analyzed in this study. The thalweg line is a stream line where the maximum velocity occurs, whereas the separation area is the boundary between the main flow and the recirculation zone. Model tests with 5 different arm lengths of the ￢-type groynes were conducted by changing the velocity. The LSPIV (Large-Scale Particle Image Velocimetry) technique was used to measure and analyze flow variation around the ￢-type groynes. The velocity in the main channel measured to be increased by 1.5 times. The velocity variation on groyne arm length is little. The width of the thalweg lines (TCL) was changed to 55 - 57% of the channel width. The Froude number did not affect the thalweg line (TCL) and separation line (Sh) changes, however.
