加载中…压力的空间离散方式的选择
(2013-08-15 09:53:31) 以下是本人对压力的空间离散方式的学习内容的理解和整理：
FLUENT的计算设定时，压力的空间离散方式设定界面如下图所示：
可供选择的方式有Standard, PRESTO!, Linear, Second Order和Body Force
Weighted.
对大多数case来说，Standard方式就足够好了，但是一些类型的case需要考虑用其他模式。
1.Body-force-weighted方式：适用于有显著的body force的计算（如重力、离心力、磁力）
2.PRESTO!
方式：适用于有高旋流强度流、高雷利数自然对流、高速旋转流、含有多孔介质的流动以及流域形状有强烈弯曲的流动。
3.second-order方式：适用于可压缩流，另外当其他模式精度不够理想时也可用二阶模式提高计算精度。（需要注意的是，对于网格质量不够好的case来说，直接选用second-order方式很可能引起不收敛。）
有以下几点需要注意：
1.second-order模式不能用于多孔介质
2.VOF多相流模型只可以选择PRESTO!模式和Body-force-weighted模式
3.欧拉多相流模型不需要定义压力插值模式
liner方式：帮助文件中仅仅提到它是采用相邻单元压力平均值作为控制单元表面压力的。
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帮助文件原文：
As discussed in Pressure Interpolation Schemes in the Theory
Guide, a number of pressure interpolation schemes are available
when the pressure-based solver is used in ANSYS FLUENT. For most
cases the “standard” scheme is acceptable, but some types of models
may benefit from one of the other schemes:
For problems involving large body forces, the
body-force-weighted scheme is recommended.
For flows with high swirl numbers, high-Rayleigh-number
natural convection, high-speed rotating flows, flows involving
porous media, and flows in strongly curved domains, use the PRESTO!
scheme.
For compressible flows, the second-order scheme is
recommended.
Use the second-order scheme for improved accuracy when one of
the other schemes is not applicable.
Important:
The second-order scheme cannot be used with porous media or
porous jump.
Important:
Only PRESTO! and body-force-weighted schemes are available for
the VOF model.
Note that you will not specify the pressure interpolation
scheme if you are using the Eulerian multiphase model. ANSYS FLUENT
will use the solution method described in Solution Method in ANSYS
FLUENT in the Theory Guide for Eulerian multiphase
calculations.
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