摘要
運(yùn)動物面粘流場數(shù)值求解技術(shù)已成為現(xiàn)代計算流體力學(xué)研究的熱點(diǎn)之一，而其中的關(guān)鍵技術(shù)就是動網(wǎng)格的生成方法以及基于動網(wǎng)格技術(shù)的數(shù)值求解方法。
本文針對非結(jié)構(gòu)運(yùn)動網(wǎng)格生成技術(shù)研究，并將動網(wǎng)格技術(shù)與非結(jié)構(gòu)同位網(wǎng)格有限體積法結(jié)合對Navier-Stokes方程進(jìn)行數(shù)值求解，建立了基于非結(jié)構(gòu)動網(wǎng)格的非定常數(shù)值離散計算模型及數(shù)值計算方法，編制了數(shù)值求解程序，并完成了算例驗證。
本文發(fā)展了兩種非結(jié)構(gòu)動網(wǎng)格生成技術(shù)，一種是在標(biāo)準(zhǔn)彈簧法基礎(chǔ)上進(jìn)行了改進(jìn)，提出了一種改進(jìn)的彈簧近似法，該方法除考慮標(biāo)準(zhǔn)彈簧法中的防止網(wǎng)格節(jié)點(diǎn)相互碰撞，還考慮了網(wǎng)格變形的扭轉(zhuǎn)效應(yīng)，空間及邊界效應(yīng),使得網(wǎng)格的變形能力大幅提高。第二種動網(wǎng)格技術(shù)為局部重構(gòu)法，該方法能夠有效的解決彈簧法不能解決的物體大幅值運(yùn)動問題。本文將Delaunay三角化方法應(yīng)用到運(yùn)動網(wǎng)格的重構(gòu)中，充分利用Delaunay三角化方法的快速生成效率及接近正三角形的性質(zhì)，引入的加密邊界作為“窗口”的方式提高了Delaunay三角化方法的布點(diǎn)能力，并編制了基于改進(jìn)彈簧法的非結(jié)構(gòu)動網(wǎng)格程序和改進(jìn)局部重構(gòu)法的動網(wǎng)格生成程序。
本文在ALE法的基礎(chǔ)上建立了動網(wǎng)格技術(shù)與SIMPLE算法相結(jié)合的數(shù)值計算模型，給出了適合動網(wǎng)格技術(shù)的，滿足幾何守恒定律的數(shù)值離散方法及邊界條件。動網(wǎng)格技術(shù)中網(wǎng)格信息傳遞方式的精度決定計算精度，本文采用雙線性插值結(jié)合ENO方法計算待插點(diǎn)的流場信息參數(shù),這種插值方法的計算精度達(dá)到二階精度。利用FORTRAN語言編寫了基于非結(jié)構(gòu)動網(wǎng)格技術(shù)的數(shù)值計算程序，并研究了圓柱橫向周期性振蕩問題，經(jīng)過與FLUENT軟件的計算結(jié)果對比，結(jié)果表明本文編制的基于非結(jié)構(gòu)運(yùn)動網(wǎng)格技術(shù)的數(shù)值計算程序是可靠的，可用于開展相關(guān)運(yùn)動物體流場的數(shù)值計算模擬。
本文利用所編制的程序開展了圓柱柔性變形及圓柱后緣柔性板變形的流場特性研究，研究發(fā)現(xiàn)物體的柔性變形能夠改變原流場的結(jié)構(gòu)，使得渦的脫落位置后移，圓柱后緣柔性板的應(yīng)用還可以使渦的脫落變得不再規(guī)律。柔性變形物體的這一特性對于抑制渦激振動有著現(xiàn)實(shí)的意義。

關(guān)鍵詞：非結(jié)構(gòu)動網(wǎng)格；局部重構(gòu)；運(yùn)動邊界；ALE方法；粘流場數(shù)值計算方法 ；FORTRAN語言


Abstract
The article studied the unstructured dynamic mesh technology and combines unstructured dynamic meshes technology with the finite volume method to solve Nervier-Stokes equations. And establishes calculation model based on the unsteady numerical discrete of the unstructured dynamic meshes.
This paper developed two kinds of dynamic mesh generation technologies. One is the improved spring analogy; the method is improved on basis of the standard spring analogy method. Improved method besides considering affective of preventing the collision between grid nodes in standard spring method and considering reverse 、 space and boundary effects. Those effects make the deformation of grids enhance greater than standard spring analogy method. The second dynamic mesh method is partial reconstruction. The method can effectively solve objects’ large motion which is that the spring analogy can not solve. This paper proposes an improved method, which will improve the stationing ability of Delaunay triangle methods, avoid the tedious steps in extracting window boundary, and boost computational speed and assure the quality of the grid. At last we compile two Programs. The first is unstructured dynamic mesh program bases on improved spring analogy. The second is unstructured dynamic mesh program bases on partial reconstruction.
This paper establishes numerical model which combined dynamic mesh technology with SIMPLE algorithm and gives discrete method of numerical simulation and boundary conditions and GCL’s discrete form which are appropriate for dynamic mesh technology. The accuracy of grid information transmission determines accuracy of simulation in dynamic mesh numerical simulation. This paper combines bilinear interpolation with ENO interpolation to calculate the interpolated parameters. This interpolation method has second order accuracy. The paper compiles numerical calculation program which bases on the unstructured dynamic mesh technology with help of FORTRAN language. And than uses the program study the Periodic oscillation of the horizontal cylinder. We find that the program is reliable after compare calculation results with FLUENT software’s and can be used to solve the Numerical Analysis of the moving body.
Objects’ flexible deformation is expected to suppress adverse effects of vortex-induced vibration in the marine engineering. By preliminary study of ours two cases, we find that objects’ flexible deformation can change the structure of original flow, and make the vortex shedding location shift to the rear. Flexible plates’ application, which is edge of cylinder, can make the vortex shedding is no longer rules, and effectively inhibits objects’ vortex-induced vibration.

Key words: Unstructured dynamic mesh; Local reconstruction; Move boundary; ALE method; numerical computation method of viscous flow; FORTRAN language






















目 錄
摘要 I
Abstract III
目 錄 V
Contents VII
第1章 緒 論 1
1.1 研究背景 1
1.2國內(nèi)外研究現(xiàn)狀 2
1.2.1 網(wǎng)格技術(shù)發(fā)展概述 2
1.2.2 非結(jié)構(gòu)動網(wǎng)格技術(shù)發(fā)展概述 3
1.2.3圓柱受迫振動研究進(jìn)展 5
1.3論文主要..