Bernoulli’s Principle explains how the pressure of a moving fluid varies with its speed of motion. Bernoulli, a Swiss mathematician, explained how the pressure of a moving fluid (liquid or gas) varies with its speed of motion. It states that as the velocity of a moving fluid (liquid or gas) increases, the pressure within the fluid decreases
标签: Bernoulli effect
The concept of pressure is central to the study of fluids. A pressure can be identified for every point in a body of fluid, regardless of whether the fluid is in motion or not. Pressure can be measured using an aneroid , Bourdon tube , mercury column, or various other methods.
The concepts of total pressure and dynamic pressure arise from Bernoulli's equation and are significant in the study of all fluid flows. (These two pressures are not pressures in the usual sense - they cannot be measured using an aneroid, Bourdon tube or mercury column.) 
In a CFD analysis, the flow domain is subdivided in a large number of computational cells. All these computational cells together form the so-called mesh or grid. The number of cells in the mesh should be taken sufficiently large, such that an adequate resolution is obtained for the representation of the geometry of the flow domain and the expected flow phenomena in this domain.
标签: GRID
Attributes controlling various aspects of the boundary layer mesh generation process can be applied to any region or face of the geometric model, and include the following information:
the entity to apply the attribute
the type of boundary layer
the thickness of the first layer
the total thickness of the boundary layer
the number of layers 
标签: boundary layer
Hemodynamics can be defined as the physical factors that govern blood flow. These are the same physical factors that govern the flow of any fluid, and are based on a fundamental law of physics, namely Ohm's Law, which states that current (I) equals the voltage difference (ΔV) divided by resistance (R).
标签: hemodynamics
Aortic dissection is a potentially life-threatening condition in which there is bleeding into and along the wall of the aorta, the major artery carrying blood out of the heart.
An aortic dissection is classified as type A or B depending on where it begins and ends.
Type A begins in the first (ascending) part of the aorta.
Type B begins in the descending part of the aorta.
the mean pressure in arteries, is approximately 100mmHg. This pressure was applied to the flow domain as the operating condition. 100mmHg corresponds to 13332.24Pa, which was input into FLUENT.
Left: Subject specific aortic geometry with the three analyzed cross-sections CS1-CS3 marked. Right: Mean inlet velocity in one subject, with time positions t1 - t4 marked. The positions correspond to maximum acceleration, maximum velocity, maximum retardation, and minimum velocity. 
二维空间中曲线之曲率
表示曲线弯曲程度的量.
平面曲线的曲率就是针对曲线上某个点的切线方向角对弧长的转动率，通过微分来定义，表明曲线偏离直线的程度。曲率越大，表示曲线的弯曲程度越大。
三维空间中曲面之高斯曲率
高斯曲率决定曲面的内蕴几何
从球面剪取一片曲面，其高斯曲率为正常数。反过来说，局部而言，任何具正常曲率的曲面都可以等距地映射成球面的一部分。
类似地，从双曲曲面剪取的一片，其高斯曲率恒等于―1，而反过来说曲率等于―1的曲面与双面曲面局部相等。双曲曲面曾在讨论欧氏第五公理时论及。
标签: WSS cuvature tortuosity
思考：血流真的很复杂啊，无论如何，都要根据研究的目的来进行简化，要模拟近似真实的周期性搏动的动脉血流，matlab是最好的选择，其次编写udf，再次定义profile。而要研究主动脉几何形态对WSS分布的影响，可以简化为定常流动，而忽略周期性搏动。走弯路了，不过也有新的发现。
Outflow b.c. - multiple outlets
If you have multiple outflows you need to specify the flow split otherwise Fluent assumes that the flow is split equally
If you don’t know the flow split, or your aim is to predict the split, then you can’t use this b.c
Although you could use outlet b.c.s to get an initial estimate and change them to a Pressure b.c to accelerate convergence
The percentage increase of wall shear stress of the spiral flow over the non-spiral flow at the phase of the cardiac cycle with lowest shear stress is shown in Figure 2. It should also be noted at this point that high wall shear stress will also mean a lower wall normal stress, therefore cyclic loading may be reduced.
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