Flow Simulations, Inc.
Computational Fluid Dynamics (CFD) Models
Provided on a Consulting Basis for Industry
Contours of liquid volume
fraction inside of a crude
vacuum distillation tower
Eulerian multi-phase model

CFD Modeling of Fans



Flow Simulations has experience with cfd modeling of fans and mixing tanks both in steady state and transient modes.

When modeling steady state phenomena, the shape of the fan curve may have a large effect upon the simulation results. Thus the standards or default flat velocity profile may not be adequate for some intstances. While Fluent will permit the user to input a polynomial for 2-D velocity input conditions, no such fuctionality is provided for 3-D. Thus to capture the 3-D inlet velocity conditions correctly a C-subroutine must be written to specify the velocities.

Centrifugal Fan Characteristics and Velocity Profiles





Here is the shape of a typical centrifugal fan and the velocity profiles in both directions


Velocity Vectors near the inlet from a Centrifugal Fan subroutine



Here are the results from the C-subroutine showing velocity vectors a little bit in from the velocity inlet.


Thus is the wrong profile is used in modeling airflow into a duct, and insufficient duct length is available for the profile to reach 'equilibrium', then the results will not be correct if the flat inlet profile is assumed.