Numerical Simulation of Hydrodynamics on Dongsha Atoll using High-Order Shallow-Water Model

  • 戴 琦

Student thesis: Master's Thesis


A high-order and high-resolution shallow-water model (SWM) is based on the depth-averaged and nonlinear shallow-water equations (SWEs) which is developed and applied for simulating the ocean circulation of Dongsha waters The surface ele-vation (η) and specific discharge per unit width in x and y direction (qx qy) are used as variables in the SWM instead of those used in the previous study The (η qx qy) based on SWM is more accurate as well as reasonable to deal with the inflow boundary con-ditions It takes the advantage to have better conservative properties than that of (η u v) variables High-order 9-node quadrilateral element is employed for the space inter-polation and θ-method is used for time integration The developed model is first ap-plied to a standing wave propagating in a flat bottom channel The results of 9-node quadrilateral element SWM are compared with that of the low-order 3-node triangular element SWM and the better accuracy is found Sensitivity study of the θ-method is also performed It is shown that θ = 0 67 is the optimal value for both 9-node SWM A high-resolution SWM with spatial resolution 120-5000 m is then applied to study the hydrodynamics of the Dongsha waters Computed results show detailed ocean circulation inside the Dongsha Atoll Computed results are in good agreement with that of the field measurements at ebb and flood tides respectively It is interest-ing to note that there is a pair of periodically moving clockwise/counterclockwise vor-tices along the edge of northern and southern entrance channels General feathers of ocean circulation of Dongsha waters by SWM is also consistent with the results com-puted by POM (Princeton Ocean Model)
Date of Award2017 Jul 25
Original languageEnglish
SupervisorShih-Chun Hsiao (Supervisor)

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