發(fā)布時(shí)間：2018-05-04 22:06

  本文選題：固體懸浮液 + 變換場(chǎng)方法　； 參考：《中國(guó)科學(xué)院研究生院（海洋研究所）》2014年博士論文

【摘要】：湍流底邊界層的物理性質(zhì)和動(dòng)力過程十分復(fù)雜，其水動(dòng)力特征對(duì)于海洋工程、海洋生物等學(xué)科具有重要的研究意義和應(yīng)用價(jià)值。但是由于其特殊的地理位置和復(fù)雜的動(dòng)力系統(tǒng)，觀測(cè)數(shù)據(jù)和理論模型非常難獲得，一直是物理海洋學(xué)、海洋環(huán)境工程及生物學(xué)研究的熱點(diǎn)之一。本論文主要的工作：一方面從理論上研究了海底懸浮液的有效粘性的消減機(jī)制；另一方面通過建立兩種新的渦粘性參數(shù)化形式，建立湍流底邊界層動(dòng)力系統(tǒng)的理論模式并得到其解析解。研究?jī)?nèi)容可分為三個(gè)方面： 1.在高濃度懸浮液的條件下，利用變換場(chǎng)理論，根據(jù)Stokes方程，研究了懸浮液的有效粘性隨顆粒尺度的變化特征。統(tǒng)計(jì)結(jié)果表明：一定的顆粒濃度下（中或高），在一個(gè)元胞內(nèi)增加顆粒的尺度或者減少單位體積內(nèi)的顆粒數(shù)量，可大幅度地減小固體懸浮液的有效粘性。本工作揭示了固體顆粒尺度的變化可控制懸浮液的有效粘性的機(jī)制。 2.給出新的參數(shù)化垂直渦粘性的三次多項(xiàng)式形式az2(1z/d)，基于簡(jiǎn)化的Navier Stokes方程，利用超幾何函數(shù)的方法，，得到了湍流粗糙底邊界層的動(dòng)力系統(tǒng)的解析解。另外，推導(dǎo)出湍流底邊界層的其他的動(dòng)力參數(shù)，如底剪應(yīng)力，Ekman傳輸，Ekman抽吸及近底部速度分布場(chǎng)，從理論上研究了湍流底邊界層特征量的分布特征。進(jìn)一步，通過數(shù)值結(jié)果的分析，得出底邊界層的總速度，虧損速度及其剪應(yīng)力受平均流的角頻率和地球自轉(zhuǎn)影響比較大；而底邊界層的動(dòng)力結(jié)構(gòu)對(duì)于底邊界層頂部粗糙度不敏感。 3.推導(dǎo)出在另一個(gè)新的渦粘性形式az (1z/d)2下的湍流底邊界層的動(dòng)力系統(tǒng)的解析解。并且通過數(shù)值分析得到：湍流底邊界層的速度剖面同樣對(duì)于平均流的角頻率和地球自轉(zhuǎn)影響之比依賴性較大；但是對(duì)于底邊界層頂部粗糙度不敏感。通過和潮流的實(shí)際觀測(cè)數(shù)據(jù)對(duì)比，在速度的振幅上擬合基本一致。 本論文的工作從理論上研究了湍流邊界層渦粘性的影響機(jī)制和參數(shù)化形式，是研究底邊界層的動(dòng)力影響因素重要的手段和方法。
[Abstract]:The physical properties and dynamic processes of turbulent bottom boundary layer are very complex. The hydrodynamic characteristics of turbulent bottom boundary layer are of great significance and application value for marine engineering and marine biology. However, because of its special geographical location and complex dynamic system, observation data and theoretical models are very difficult to obtain, which has been one of the hot spots in physical oceanography, marine environmental engineering and biology. The main work of this thesis is as follows: on the one hand, the effective viscosity reduction mechanism of submarine suspensions is theoretically studied; on the other hand, two new parameterized forms of vortex viscosity are established. The theoretical model of turbulent bottom boundary layer dynamic system is established and its analytical solution is obtained. The research contents can be divided into three aspects: 1. Under the condition of high concentration of suspensions, the change characteristics of effective viscosity of suspensions with particle size are studied by using the transform field theory and Stokes equation. The statistical results show that the effective viscosity of solid suspensions can be greatly reduced by increasing the size of particles or reducing the number of particles per unit volume in a cell at a certain particle concentration (medium or high). This work reveals the mechanism that the change of solid particle size can control the effective viscosity of suspensions. 2. In this paper, a new parameterized cubic polynomial form of vertical vorticity is given. Based on the simplified Navier Stokes equation, the analytical solution of the turbulent dynamic system of rough bottom boundary layer is obtained by using the method of hypergeometric function. In addition, other dynamic parameters of the turbulent bottom boundary layer, such as the bottom shear stress Ekman transport Ekman pumping and the velocity distribution near the bottom, are derived, and the distribution characteristics of the turbulent bottom boundary layer characteristic quantities are theoretically studied. Further, through the analysis of the numerical results, it is concluded that the total velocity, the depleted velocity and the shear stress of the bottom boundary layer are greatly affected by the angular frequency of the average flow and the rotation of the earth. The dynamic structure of the bottom boundary layer is insensitive to the top roughness of the bottom boundary layer. 3. An analytical solution for the dynamic system of the turbulent bottom boundary layer is derived under another new form of vortex-viscosity, Az / D ~ (2). The numerical results show that the velocity profile of the turbulent bottom boundary layer is also dependent on the ratio of the angular frequency of the mean flow to the rotation of the earth, but it is not sensitive to the top roughness of the bottom boundary layer. By comparing with the observed data of the tidal current, the fitting of the velocity amplitude is basically consistent. In this paper, the influence mechanism and parameterized form of vortex viscosity in turbulent boundary layer are studied theoretically, which is an important means and method to study the dynamic influence factors of bottom boundary layer.
【學(xué)位授予單位】：中國(guó)科學(xué)院研究生院（海洋研究所）
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類號(hào)】：P731.26

【參考文獻(xiàn)】

相關(guān)期刊論文 前7條

1 魏皓;趙亮;劉廣山;江文勝;;淺海底邊界動(dòng)力過程與物質(zhì)交換研究[J];地球科學(xué)進(jìn)展;2006年11期

2 汪亞平,高抒,賈建軍;海底邊界層水流結(jié)構(gòu)及底移質(zhì)搬運(yùn)研究進(jìn)展[J];海洋地質(zhì)與第四紀(jì)地質(zhì);2000年03期

3 費(fèi)祥俊;高濃度渾水的賓漢極限剪應(yīng)力[J];泥沙研究;1981年03期

4 費(fèi)祥俊,朱程清;高含沙水流運(yùn)動(dòng)中的賓漢切應(yīng)力[J];泥沙研究;1991年04期

5 厚宇德;超幾何函數(shù)在量子力學(xué)上的應(yīng)用[J];哈爾濱商業(yè)大學(xué)學(xué)報(bào)(自然科學(xué)版);2002年03期

6 朱嘉麟;超幾何方程的解在函數(shù)展開中的應(yīng)用[J];計(jì)算物理;1988年04期

7 曹祖德,王桂芬;波浪掀沙、潮流輸沙的數(shù)值模擬[J];海洋學(xué)報(bào)(中文版);1993年01期

本文編號(hào)：1844869