Form factor
Form factor turns up in 2 fields: tides, mechanical. Here is what it means to the people in each one.
Form factor in tides
A ratio of diurnal to semidiurnal constituent amplitudes used to classify a tide as semidiurnal, mixed or diurnal.
The ratio of the sum of the K1 and O1 amplitudes to the sum of the M2 and S2 amplitudes. Below about 0.25 the tide is semidiurnal; from 0.25 to 1.5 it is mixed, mainly semidiurnal; from 1.5 to 3 it is mixed, mainly diurnal; above 3 it is diurnal. Planners use it to decide which prediction methods and datums behave sensibly and how much the daily highs and lows will differ.
"Form factor comes out at 1.8, so treat this as mixed, mainly diurnal, and don't trust twelfths."
Form factor in mechanical
A dimensionless ratio used to describe the shape of an object or its stress distribution.
A coefficient that accounts for the geometric shape of a component when calculating physical properties like stress, heat transfer, or drag. In structural mechanics, it relates the maximum stress in a cross-section to the average stress. Engineers use it to adjust theoretical calculations to match the actual physical behavior of irregular shapes.
"The raw calculation looks fine, but once you apply the form factor for that I-beam profile, the safety margin drops below spec."