Shape Factor

Definition

The Shape Factor ($H$) is the ratio of displacement thickness to momentum thickness. It is used to characterize the nature of the boundary layer flow (laminar vs. turbulent) and predict separation.

Formula

$H = \frac{\delta^*}{\theta}$ For laminar Blasius flow, $H e approx 2.59$.

Relationships

• Related: Displacement Thickness, Momentum Thickness