[Result Control] Calculation methods on specific entities and their differences


SimScale offers several calculation methods on different available entities such as Edge calculation, Area calculation (on faces), Volume calculations and Point data (on specific point defined under Geometry Primitives). These calculation methods can be used for creating a plot for specific solution field e.g. vonMises stress, reaction forces etc. But in defining these calculation methods, one have to be sure that which Type should be used in order to get the appropriate data he/she is looking for.

There are three available types:

  1. average: gives the average value over all nodes i.e. (1+2)/2
  2. minimum and maximum: gives minimum and maximum value of the nodes i.e. min (1,2) and max(1,2).
  3. sum: gives the sum over all nodes i.e. 1+2

To make use of a proper type, please see an example below.

Let’s suppose that we want to have the reaction force values on one of the fixed face of our geometry. Then selecting a minimum and maximum will give the minimum and maximum value of the reaction force on certain nodes of that face for a specific timestep. Generally in case of reaction force this is not what one is looking for. Since the minimum and maximum depends solely on how the mesh is discretized. Therefore, this most of the time has no physical meaning. In order to get more appropriate results in case of forces (nodal or reaction), one can use sum to get the reaction force sum over all nodes which gives results near to physical aspect.

On the other hand, asking for sum of stresses (vonMises or cauchy) on a face or whole volume has no physical meaning. Since in structural mechanics, one is interested in getting the highest and lowest stress value in an entity, which is possible to get only using minimum and maximum type.

Stirred reactor simulation - unsatisfying results
View deformed geometry in a simulation