Session: 12-02-01 Wave-Structure Interactions I
Paper Number: 124225
124225 - Experiment on the Drag Coefficient of Waves on Vegetation
Coastal vegetation serves as a natural and sustainable method for coastal protection, playing a critical role in attenuating wave energy by resisting incoming waves. Despite the significance of coastal vegetation, there remains a lack of comprehensive research on the empirical formulas for drag coefficients (CD) required for numerical models. In order to quantify the drag force, there are two methods provided to derive the drag coefficient: calibration method and direct measurement method. Calibration method calculated CD by the wave height consumption. So far, calibration method is applicable to both wave-only and wave-current conditions. However, the relationship between drag coefficient and Keulegan-Carpenter (KC) number obtained by calibration method is more dispersed than direct measurement method. On the other hand, direct measurement method calculated CD based on Morison equation, which requires the acting force and synchronized theoretical velocity, and has not been applied to flexible vegetation.
The primary objective of this study is to gain a deeper understanding of how vegetation affects wave attenuation through a series of experiments. These experiments incorporate measurements of free surface elevations, vegetation movements, and forces acting on the vegetation. By examining various conditions involving different types of vegetation, vegetation arrangement, and wave characteristics, we seek to assess and quantify their impact on wave attenuation. Particular attention will be paid to how to estimate the drag coefficient CD using direct measurement method and calibration method. The data obtained from this research will not only enhance our understanding of the dynamics between coastal vegetation and wave energy but will also provide valuable reference information for numerical models. Ultimately, it can contribute to coastal management and engineering practices, which are essential for protecting vulnerable coastal regions in the face of changing environmental conditions.
Presenting Author: Yu Hsiao National Cheng Kung University
Presenting Author Biography: Dr. Yu Hsiao
Education: Ph. D. in Hydraulic and Ocean Engineering, National Cheng Kung University, Taiwan
Current Affiliation: Postdoctoral Research Fellow in Hydraulic and Ocean Engineering, National Cheng Kung University, Taiwan
Research Interests: Experimental fluid dynamics, computational fluid dynamics
Authors:
Yu Hsiao National Cheng Kung UniversityShih-Chun Hsiao National Cheng Kung University
Philip Li-Fan Liu National Cheng Kung University
Yen-Lung Chen National Cheng Kung University
Experiment on the Drag Coefficient of Waves on Vegetation
Submission Type
Technical Presentation Only