Three-dimensional High-resolution Numerical Study of the Tide and Tidal Current in the Jiaozhou Bay and Olympic Sailing Site By Jinrui Chen Ocean University of China cooperator: Shiliang Shan, Huaming Yu, Xueen Chen E-mail:chenjinrui0@163.com Tel:+86 159 5488 2435 Oct. 2008
Overview Introduction and background Model configuration Results and discussion Conclusions Future work
Jiaozhou Bay (35 55 ~36 18 N, 120 04 ~120 23 E) Yellow sea the locality of the Jiaozhou Bay
The depth of Jiaozhou Bay
Research Significance The coastline and topography of Jiaozhou Bay has changed much in recent years. Sea grass The 29th Olympic sailing game
Since the 1980s, many articles focused on Jiaozhou Bay via numerical simulation study, obtained lots of results. Generally speaking, the resolution is not fine enough. In order to represent the complex coastline and irregular topography, I adapted FVCOM to simulate the tide and tidal current of the Jiaozhou Bay.
The advantage of FVCOM 3-D Unstructured Grid Finite Volume FVCOM combines the best attributes of finite-difference methods for simple discrete coding and computational efficiency and finite-element methods for geometric flexibility.
Model Configuration 29251 nodes 54927 triangle cells Computed area and unstructured triangular grid layout
The unstructured grid of Jiaozhou Bay Unstructured grid in the Olympic sailing center
Parameter Setting Finer resolution: 20m Coarser resolution: 3km Sigma layers number: 5 wet/dry methods M2,S2,N2,K1,O1,P1 (I used six main tidal constituents to predict the water elevation to drive the model) External Model time step: 0.2 s Tempreture and salinity: 20,32psu
Results and Discussion Tidal Analysis Tidal Currents Analysis Dye Release High-resolution Simulation at Olympic Sailing Sites
Tidal Analysis Comparison Between the Observed and Computed Tidal Constituents Station latn ( ) lon E( ) M2 S2 K1 O1 H(cm) g( ) H(cm) g( ) H(cm) g( ) H(cm) g( ) Dagang 36.083 120.30 131.78 133.14 40.09 176.79 26.60 355.45 20.41 295.85 Model 36.086 120.30 125.06 124.89 34.82 171.9 23.41 1.42 20.88 292.58 Xiaom aidao 36.050 120.417 118.92 127.60 37.55 168.98 25.18 352.07 19.61 293.43 Model 36.050 120.417 114.53 122.38 32.04 167.55 23.15 359.84 20.53 290.95
36.3 Co-amplitude and Co-phase charts 36.3 36.2 36.2 36.1 36.1 36 36 120.2 120.4 120.2 120.3 120.4 Model Results Real lines : co-amplitude lines (cm) Dashed lines: co-phase lines ( ) M2 O1
tidal current ellipse tidal type Dagang : 0.4 0.36 Xiaomaidao: 0.43 0.38 The tidal type ofjiaozhou Bay Is less than 0.5. Jiaozhou Bay and its offshore water is a regular semidiurnal tidal areas. Distribution of tidal current ellipse of M2
Parameter of M2 tidal ellipse SEMA ECC INC PHA B3 0.2493-0.2613 70.3715 20.6336 D16 0.3192 0.0206 166.2194 59.5200 8805 0.2967 0.4799 131.3327 354.873 SEMA :semi-major axis (m) ECC :eccentricity (positive value: counterclockwise) INC : inclination(degrees) PHA : phase (degrees) Distribution of tidal currents in Jiaozhou Bay (Chinese Gulf Report)
Euler residual current Euler residual current in the Jiaozhou Bay
Tidal Energy Flux U = vh P = ρg < Uζ > P ρ :tidal energy flux ρ:density g :gravitational acceleration U ρ :volume transport vector v ρ :velocity of tidal current H :depth ζ :sea level < > :time average Garrett,C.1975
Tidal Energy Flux Horizontal distribution of tidal energy flux at Jiaozhou Bay
Dye Release Spatial distribution of dye in Jiaozhou Bay from 1 to 958 hours
Olympic sailing site --Euler residual current before constructed the sailing center after constructed the sailing center
Olympic sailing site --tidal current At flood movement At ebb movement
Olympic sailing site --Tidal Energy Flux Horizontal distribution of tidal energy flux in the field of play for the 2008 Olympic sailing competition
Conclusion The tides are semi-diurnal in Jiaozhou Bay. Tidal waves propagate from northeast to southwest, it is an anticlockwise system. The tidal currents are rectilinear currents. Euler residual currents show multi-vortex structures near the mouth of Jiaozhou Bay Tidal energy propagates from northeast to southwest. Because of the special topography, the tidal energy is higher than any other areas at the mouth of the bay. Dye release tests showed that it is a relatively active zone of water exchanging near the mouth of Jiaozhou Bay. Construction of Qingdao Olympic Sailing Center only has obvious effect on the area near the sailing center.
Future work Collecting more observed data Considering Baroclinic, Wind Field and Heat Flux et al. Cases study in different coastaline in different period