Boundary Conditions

Boundary conditions define how a system (for example, a structure or a fluid) interacts with its environment. Fixations, loads, pressures, flow rates or velocities are all examples of boundary conditions.

A boundary condition consists of three pieces of information:

  1. Boundary condition types

    SimScale offers a large set of boundary condition types for simulations. This section links to descriptions of the available boundary condition types.

  2. Boundary condition values

    This is where we define the value of the condition (speed, temperature, force etc.)

  3. Boundary condition assignments

    A boundary condition is usually only assigned to the domain’s boundary. Each boundary condition must be linked to at least one Surface or Edge where something enters or exits the analysis.

Boundary condition types

SimScale offers many boundary condition types for different types of applications. Boundary conditions are only displayed when they can be applied to the type of analysis being worked on. The following list shows the available boundary condition types, what each type means and where they can be used. For advanced users, the pages also show how the boundary condition types translate to the solver input files.

Fluid Dynamics

Solid Mechanics


Boundary condition values

For simple cases, boundary conditions are defined by a single value of a given variable (velocity, temperature, pressure…). For advanced cases where a fixed value is not enough, alternative techniques are available:

Data Privacy