The Flow Module is the heart of the CFD-ACE+ solver and is used for most simulations. It allows the user to model almost any gas or liquid system. The code solves the Navier-Stokes differential equations discretized over a finite volume. Both internal and external flows at any speed can easily be simulated yielding a numerical solution of the pressure and velocity fields. Salient features of the Flow Module include

• Pressure based finite volume method (FVM) formulation Navier-Stokes equation flow solver
• All flow speeds
• Newtonian and non-Newtonian fluid viscosity options
• Rarified gas flows with slip walls
• Several body forces
• Swirl model for 2D axisymmetric geometries
• Porous media and membranes
• Thin walls
• Implicit, strong conservation formulation for all PDEs
• Upwind, Central, 2nd Order upwind, 2nd Order Limiter, 3rd
  Order and Smart spatial differencing schemes
• Euler and Crank-Nicolson temporal differencing methods
• Supports multi-block structured; general unstructured (arbitrary type elements); arbitrary mesh interfaces; overset mesh filaments and particle clusters; and moving, deforming and rotating grids with sliding mesh interfaces

These features are available for use in conjunction with one or more of the other CFD-ACE+ modules to provide multiphysics solutions to complex real world engineering problem. The CFD-ACE+ Fluid Dynamics Module has been extensively validated for a wide range of applications as documented in the validation test cases that are delivered with the software.