Result control allows users to define extra simulation result outputs. This can be a specific solution field like vorticity, calculation of forces and moments on the facade of a monument in a wind comfort simulation, or areas of high stress in a structural analysis.
In an iterative solution where the initial estimations of variables are updated per iteration one should expect to see those variables come to a level and don’t change anymore. Result control items can be a great way to assess convergence of these variables by studying the pattern in which they stabilize as the simulation progresses. This is particularly helpful in saving time and core hours by stopping the simulation when it is not going in the desired direction.
The user can find the result control item inside the simulation tree. A general explanation of the result control settings for each type of analysis in SimScale can be seen below:
Result control items are a part of simulation setup and need to be set in advance before the simulation is run.
Forces and moments: Calculates the forces and moments on a specific surface. This is used, for example, when one wants to find the drag and lift coefficient of a car surface in the aerodynamic analysis.
Surface data: Calculates average or an integral of the simulation results on a specified surface area.
Scalar transport: This result control enables you to insert a passive scalar into your model to act as a tracer. Moreover, you will need to define the diffusion coefficient and the source of the scalar quantity with a geometry primitive.
Probe points: One can place points for the measurement of the flow variables inside the model. They can be thought of as virtual hot wires, pitot tubes, or pressure taps. Users can define the probe points by creating point geometry primitives and setting the coordinates of those points.
Field calculations: The user can enable additional calculations in the flow domain to explore flow characteristics. The calculations that can be done are pressure fields, turbulence, vorticity, mean age of fluid, and wall shear stress. Here it is also possible to define result controls for the pressure coefficient.
Learn with an example!
Learn about the result control items and how they are applied on a Simple Rotating Pump with an interactive video following a comprehensive analysis.
Solution fields: Here quantities like displacements, strain and stress types, reaction forces, can be set for calculation.
Edge calculation: Calculates statistical data of a chosen parameter on an edge. For example, the average displacement on an edge in the x-direction.
Area calculation: This gathers statistical data of a surface in the model. For example, the minimum and maximum values of velocity in the y-direction.
Volume calculation: Statistical data for a volume. For example, the sum of forces and strains in the z-direction or all directions.
Point data: This is similar to probe points in CFD analysis where the user can define points that will be measurement points for the simulation.
To know more about the result control settings for structural simulations interested readers are requested to visit this document.
LBM and PWC
Professional users can find the Result control settings for the LBM and PWC analysis in the list below:
Forces and moments: Calculates the forces and moments of a specific surface. For example, you can enable this when you want to observe the wind load on a building surface facing the predominant wind direction.
Probe points: One can place points to use as measurement points in the model. Moreover, the user can enable this if there are particular areas of interest that need attention.
Field calculations: Additional calculations that are done in the domain of the simulation. You can add additional calculations for vorticity, friction velocity, or surface normals.
Transient output: One can export the transient output of the whole or a fraction of the simulation by controlling the write frequency. Both flow-domain and surface fields can be exported.
Statistical averaging: The user can change the settings of how the statistical averaged results are exported and the settings are similar to that in the transient output. However, instead of a transient set of results, they will be averaged into one result.
Snapshot: Simulation results from the last time step of the simulation are shown as a snap. It is also important to remember that this is only available for PWC simulations. The domain of the snapshot can be the same domain as the region of interest or can be defined by a geometry primitive.
Detailed information on the results of LBM simulations can be found here: