Page 86 - ansys

4.2.11 Unit Systems

ANSYS FLUENT allows you to work in any unit system, including inconsistent units. Thus, for example,
you may work in British units with heat input in Watts or you may work in SI units with length defined
in inches. This is accomplished by providing ANSYS FLUENT with a correct set of conversion factors
between the units you want to use and the standard SI unit system that is used internally by the solver.
ANSYS FLUENT uses these conversion factors for input and output, internally storing all parameters
and performing all calculations in SI units. Both solvers always prompt you for the units required for
all dimensional inputs.
Units can be altered part-way through a problem setup and/or after you have completed your
calculation. If you have input some parameters in SI units and then you switch to British, all of your
previous inputs (and the default prompts) are converted to the new unit system. If you have completed
a simulation in SI units but you would like to report the results in any other units, you can alter the unit
system and ANSYS FLUENT will convert all of the problem data to the new unit system when results
are displayed. As noted above, all problem inputs and results are stored in SI units internally. This
means that the parameters stored in the case and data files are in SI units. ANSYS FLUENT simply
converts these values to your unit system at the interface level.

79