For the pure 3d advective problem , solution can be found by the characteristics method 在验证计算的同时，分析了不同re流动特性的变化。
3.
Research has demonstrated that advective flow , which originates near the surface of the ocean where suspended particulate matter accumulates , transports some of that matter and water to the vents 研究显示大洋表面附近形成的对流潮将聚集的浮游颗粒物质和水输送到喷口处。
4.
In the numerical solution algorithm , the method of characteristics , analytic method and galerkin finite element method ( galerkin - fem ) can be chosen to solve the advective equation , diffusion equations , reaction ( source / sink ) equations , propagation equations and pressure poisson equation , respectively . the developed new algorithm has been verified using analytical solution of circular conduit flow in a reynolds number range of 100 < re < 1 000 and experimental data of the laminar flow over a backward - step facing step . the flow properties are well characterized by this three - dimensional numerical model 本论文在评述三维粘性流动数学模型已有研究成果的基础上，着重在数值计算方法的选择和定解条件的给定对数学模型计算结果的影响进行了研究，并首次提出了求解三维纯对流方程的高精度的拟协调单元法，建立了三维低雷诺数re流动的数学模型，并在圆管流动、台阶突扩矩形管道流动中得到验证和应用。
5.
The solution algorithm involves tracing the characteristic lines backwards in time from a upwind element of an interior point . two advanced mehtods , quasi - consistence and consistence hexahedral element method , for three - dimensional advective problem are developed . and comparison of these two methods with linear interpolating function method is implemented 当re 400时，流动明显地具有二维性； re 800时，流动具有一定程度的三维性，而且出现了次回流区； re 1000时，流动则具有明显的三维性。
6.
( 5 ) several group experimental result of solute transport in fractured medium was analysed in different direction . an experience formula of nacl solution was summarized , which changed in different position . the coefficient of advective - dispersive was deduced by means of back analysis based on the experimental results , which suited to solute transport in a single fracture of rock ( 5 )通过裂隙中溶质运移的多组实验结果进行横、纵向的比较分析，总结出了nacl溶液浓度沿程变化的经验公式；结合实验结果针对所推导出的数学模型拟合出适合单裂隙岩体的溶质运移弥散系数。
7.
Important missing aspects are : turbulent flow , numerical discretization techniques specially the relevant and difficult topic of numerical treatment of advection and related numerical methods of solution , variable property fluids , boundary layers , stability , etc . rather , it focuses on more primitive and fundamental issues of numerical treatment of advective equation and proper formulation of initial boundary value ( ib vp ) . numerical problems associated with advective dominated transport include spurious oscillation , numerical dispersion , peak clipping , and grid oriention . however , the key of numerical solution of three - dimensional advective problem is searching for a high - precision interpolating function , which can keep the computational stability and low damping 3 、针对三维纯对流方程提出了实用的拟协调单元模式，并与线性插值模式和协调单元模式比较后表明，在物理量大梯度变化的情况下，线性插值模式会产生较大的数值阻尼，导致解的失真；协调单元模式具有极高的计算精度和良好的计算稳定性，还可较好地克服数值阻尼，但由于计及物理量的二阶导数项，计算工作量大，边界条件给定尚存在一定的困难；而拟协调单元模式不仅具有协调单元模式计算精度高的优点，还避免了物理量的二阶导数项，可大大地减少计算工作量。
8.
( 4 ) according to the 2 - d advective - dispersive equation of pore medium and combining the result of experiment , the difference between experiment and calculation was located by macroscopical analysis . a new mathematical model suiting to fractured medium was deduced from revised pore medium model . the correction and practicability were verified by the result of experiment ( 4 )依照孔隙介质二维溶质对流弥散方程，结合实验所取得的成果，进行宏观比较分析，找出实验与计算的差距，然后对孔隙介质模型作进一步的修正，推导出了适合单裂隙岩体二维溶质运移的数学方程，并通过具体的实验结果验证了模型的正确性和实用性。
