{"id":17047,"date":"2018-11-05T08:23:33","date_gmt":"2018-11-05T08:23:33","guid":{"rendered":"https:\/\/www.simscale.com\/?page_id=17047"},"modified":"2026-02-12T12:39:20","modified_gmt":"2026-02-12T12:39:20","slug":"boundary-conditions","status":"publish","type":"page","link":"https:\/\/www.simscale.com\/docs\/simulation-setup\/boundary-conditions\/","title":{"rendered":"Boundary Conditions"},"content":{"rendered":"\n

Boundary conditions define how a system, ( for example, a structure or a fluid ), interacts with the environment. Fixations, loads, pressures, flow rates, or velocities are all examples of boundary conditions.<\/p>\n\n\n\n

A boundary condition consists of three pieces of information:<\/p>\n\n\n\n

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  1. Boundary condition types<\/strong>: SimScale offers a large set of boundary condition types for simulations. This section links to descriptions of the available boundary condition types.<\/li>\n\n\n\n
  2. Boundary condition assignments<\/strong>: A boundary condition is usually only assigned to the domain\u2019s boundary. Each boundary condition must be linked to at least one surface or where something enters or exits the domain.<\/li>\n\n\n\n
  3. Boundary condition values<\/strong>: This is where we define the value of the condition (speed, temperature, force, etc.);<\/li>\n<\/ol>\n\n\n\n

    Boundary Condition Types<\/h2>\n\n\n\n

    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 page also shows how the boundary condition types translate to the solver input files.<\/p>\n\n\n\n

    Fluid Dynamics<\/h3>\n\n\n\n