In a Nut Shell: By
the Buckingham Pi Theorem the number of Pi terms (dimensionless products)
equals the number of variables minus the
number of dimensions describing the problem.
To
start identify all the pertinent variables describing the problem. This is a critical first step. The
idea
is to select the fewest number of relevant variables and to then form the
dimensionless products.
If
important variable are excluded, then incorrect results will be
obtained. If extraneous variables
are included, then too many Pi terms appear in the final solution and are
difficult to eliminate. Application
of
dimensional analysis applies to any field of engineering, not just fluid
mechanics.
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