在“基本”选项卡中可以定义一般的流参数。
流动参数
This area controls the simulation type. You can choose between two types of the simulation.
在章节 稳态流和 瞬态流(非稳态流)中,介绍了每种模拟类型的具体设置和相应的选项卡。
The "Density" of the air is dependent on the altitude, temperature, atmospheric pressure and humidity. It has an effect on the dynamic behaviour of the fluid.
The value of the "Kinematic viscosity" describes the resistance of the air to deformation. It is defined as the ratio of the viscosity to the density of the air.
选项
For calculation with RWIND 3, the effects of turbulence are essential. If you want to "Consider turbulence," activate the check box. The effects of turbulent flow are characterized by chaotic changes of pressure and flow velocity, contrasting laminar flow. 进一步的说明参见。
The slip boundary condition applied to the bottom surface of the wind tunnel can be set by activating the "Slip boundary condition on bottom boundary" check box. 有关边界条件的信息,请参见章节 风洞。
如果激活“考虑表面粗糙度”复选框,则模型的每一个面的粗糙度都会被考虑(参见章节 高级)。 您可以在表面粗糙度选项卡中定义粗糙度参数。
The "User-defined dimensions of wind tunnel" check box enables you to define the tunnel size manually. 有关风洞参数的更多详细信息,请参见章节 风洞。 You can then define the tunnel dimensions on the "Wind Tunnel" tab of the "Load Cases & Combinations" dialog box.
如果勾选“保存求解器数据以继续计算”,则可以在项目关闭并重新打开后继续计算(见章节 Steady Flow )。
Member Load Distribution
The setting has an effect on the load application of the generated member loads on the model.
- 集中: The loads result in concentrated loads at relative distances along every member. The intervals of the load application points are usually very small, depending on the density of the mesh.
- 均匀: For every member, constant loads are created along the member length. Only one uniform member load is applied for each global direction.
- Trapezoidal: Similar to uniform loads, the concentrated loads are levelled along the member. They are converted into a trapezoidal distribution, however, to approximate the actual gradients.
计算参数
The "Numerical solver type" is the current CFD Solver used by RWIND 3. It is the external CFD code OpenFOAM®. 更多信息请参见章节 CFD 求解器。
The finite volume density of mesh to be applied around the model is controlled by percentage reference. This specific refinement is utilized for the model simplification and the flow calculation. The default density (20%) normally results in a relatively low number of finite volumes and a relatively fast calculation. The minimum percentage is 10%. It entails a rather coarse mesh with the smallest number of volumes. The higher the density of the mesh, the smaller the size of the finite volume cells will be. 因此,结果更加精确,但由于体积较大,计算需要更多时间。 Setting the maximum mesh density (100%) leads to very fine meshes with millions of volumes. The calculation of 3D flow on such meshes is on the edge of the capabilities of current PCs, with a calculation time of several hours to several days.
详细信息参见章节 计算网格和模型简化。
“网格细化类型”可以对模型表面的曲率或全局对距模型面的距离进行定义,请参见章节 概述, 有限体积网格。
The "Boundary layers" option controls whether the finite volume mesh next to the surfaces of the model is refined in a special way. 这种细化在模型边界附近给出了更好的结果(见图
Finite Volume Mesh with Five Boundary Layers
)。 We highly recommend activating the boundary layers and defining the number of layers NL when the surface roughness is to be taken into
account.