Using Boundary Conditions to define Summary Objects

In many simulations, critical results values occur where boundary conditions are applied. Results at these locations often influence and even drive design decisions.

An example is the inlet of a flow control device (valve). A flow rate boundary condition is applied to the inlet, and a static gage pressure is applied to the outlet. An essential result quantity is the pressure drop, which is assessed by creating a results plane at the inlet, and designating it as a summary plane. The pressure drop value is then monitored in the Decision Center where it is compared with values from other scenarios in the design study.

To simplify results extraction and design comparison, you can use boundary conditions to pre-define Summary Planes and Summary Parts. You can use a surface boundary condition (velocity, for example) to create a Summary Plane that is co-planar with the surface. Likewise, you can use a volumetric boundary condition (total heat generation) to create a Summary Part. This reduces the number of steps required to obtain critical design information.

The Decision Center lists all Summary items. They are a powerful tool for comparing results across multiple scenarios.

For more about Summary Entities...

Workflow

To Create a Summary Plane

1. Expand the Boundary Conditions branch of the Design Study bar, and expand the specific condition branch (example - "Velocity Normal").
2. Right click on the surface ID branch, and select Create summary item.

A small overlay icon appears on the surface branch:

This indicates that a Summary Plane coplanar to the surface will be created the next time the scenario is run.

To Create a Summary Part

1. Expand the Boundary Conditions branch of the Design Study bar, and expand the specific condition branch (example - "Total Heat Generation").
2. Right click on the volume ID branch, and select Create summary item.

A small overlay icon appears on the surface branch:

This indicates that the part will be designated as a Summary Part the next time the scenario is run.

To Disable Summary Item Creation

1. Expand the Boundary Conditions branch of the Design Study bar, and expand the specific condition branch.
2. Right click on the entity ID branch, and deselect Create summary item.

Notes

If a boundary condition is deleted

• If the simulation had not been run, a summary plane will not be created.
• If the simulation had been run, the Summary object remains.

If Summary Item Creation is disabled

• Disabling this option for a boundary condition does not delete an existing Summary object.
• Use the Decision Center to remove Summary objects.

If a boundary condition is modified

• The part or surface remains pre-defined as a summary item.

When a simulation is continued

• A new summary plane is not created if a summary plane already exists at a given location.
• If Create summary item is checked prior to continuing a simulation, a new summary plane (or part) is created.

When a design is cloned

• A new Summary Plane is created if the pre-defining surface is in a different location in the cloned model.

• Consider this example:

  • A pipe outlet, at X = 5, is pre-defined as a Summary Plane.
  • The design is cloned, and the outlet is moved to X = 10 in the new design.
  • At the conclusion of the two simulations, there will be a Summary Plane at X = 5 and X = 10 for both scenarios.
  • For the first design, there will be no data at the X = 10 Summary Plane.
  • For the second design, there will be data on both Summary Planes.
  • To compare outlet results for the two scenarios, use the Summary Planes at X = 5 and X =10 for the first and second scenarios, respectively.

If a boundary condition is "lost"

• If a Design is updated with modified geometry, a boundary condition may be Lost if the part or surface was removed.
• If a Summary object was pre-defined from a condition that is lost, the Summary object is not deleted.
• When the lost condition is re-assigned to a geometric entity, right click and select Create summary item to create a Summary object at the new location.

For an example of creating a summary object with a boundary condition...