海洋科学
海洋科學
해양과학
MARINE SCIENCES
2014年
12期
120-127
,共8页
底边界层%涡黏性%Coriolis参数
底邊界層%渦黏性%Coriolis參數
저변계층%와점성%Coriolis삼수
bottom boundary layer%eddy viscosity%coriolis parameter
本文通过假定底边界层湍黏性的三次多项式参数化形式,基于简化的Navier–Stokes方程,并利用超几何方程的性质,推导出了湍流粗糙底边界层的速度解析解。同时,得到了底边界层内其他的动力参数,如底剪应力、Ekman 传输、Ekman 抽吸及近底部速度分布场,从理论上讨论了均匀混合底边界层特征量分布特征。通过数值结果分析,进一步得出底边界层的总速度、亏损速度及其剪应力受平均流的角频率和地球自转影响比较大;而底边界层的动力结构对于底边界层顶部粗糙度不敏感。该涡黏性模式从理论上丰富了底边界层涡黏性的形式,为底边界层的动力系统研究提供了借鉴和理论参考。
本文通過假定底邊界層湍黏性的三次多項式參數化形式,基于簡化的Navier–Stokes方程,併利用超幾何方程的性質,推導齣瞭湍流粗糙底邊界層的速度解析解。同時,得到瞭底邊界層內其他的動力參數,如底剪應力、Ekman 傳輸、Ekman 抽吸及近底部速度分佈場,從理論上討論瞭均勻混閤底邊界層特徵量分佈特徵。通過數值結果分析,進一步得齣底邊界層的總速度、虧損速度及其剪應力受平均流的角頻率和地毬自轉影響比較大;而底邊界層的動力結構對于底邊界層頂部粗糙度不敏感。該渦黏性模式從理論上豐富瞭底邊界層渦黏性的形式,為底邊界層的動力繫統研究提供瞭藉鑒和理論參攷。
본문통과가정저변계층단점성적삼차다항식삼수화형식,기우간화적Navier–Stokes방정,병이용초궤하방정적성질,추도출료단류조조저변계층적속도해석해。동시,득도료저변계층내기타적동력삼수,여저전응력、Ekman 전수、Ekman 추흡급근저부속도분포장,종이론상토론료균균혼합저변계층특정량분포특정。통과수치결과분석,진일보득출저변계층적총속도、우손속도급기전응력수평균류적각빈솔화지구자전영향비교대;이저변계층적동력결구대우저변계층정부조조도불민감。해와점성모식종이론상봉부료저변계층와점성적형식,위저변계층적동력계통연구제공료차감화이론삼고。
The analytical solutions for the velocity distribution within the turbulent bottom boundary layer BBL are deduced by supposing an eddy viscosity of cubic polynomial form. Based on the simplified Navior-Stokes equations, the property of the hypergeometric function is used to this model. Moreover, other dynamic parameters of BBL are also obtained, such as the bottom shear stress, the Ekman transport, Ekman pumping and the velocity fields near the bottom. Thus the dynamic characteristics of well-mixed turbulent bottom boundary are discussed theoretically. Furthermore, numerical results show that the total velocity profile, Ekman velocity and shear stress are sensitive to the ratio of the tidal frequency and the Coriolis parameter, but are less influenced by the strength of capping in BBL. The mode will provide valuable information for how to select the eddy viscosity forms in the BBL theoretically and provide theoretical references for the dynamics in the BBL.