New Functionality in Version 4.2a


  • A new Slip Flow interface for modeling thermal and isothermal flows within the slip flow regime. The Slip Flow interface makes it possible to model the flow of the gas, including a thin layer of gas adjacent to the walls (Knudsen layer), where the gas is significantly rarefied. The Slip Flow interface is available in 2D and 3D.
  • A new Transitional Flow interface, which you can use to model isothermal flows across the full range of Knudsen numbers from the laminar flow limit to the molecular flow limit. The Transitional Flow interface is available in 2D.

New Models

  • Knudsen’s Minium: This model, using the Transitional Flow interface, shows that the flow rate of a rarefied gas between parallel plates exhibits a minimum (Knudsen’s minimum) at a Knudsen number of about 1.
  • Slip Flow Benchmark: A benchmark model of the flow between to sealed chambers connected by a microchannel with conducting walls. This model uses the Slip Flow interface.