Paul Richard Heinrich Blasius (9 August 1883 – 24 April 1970) was a German fluid dynamics physicist.
Blasius provided a mathematical basis for boundary-layer drag but also showed as early as 1911 that the resistance to flow through smooth pipes could be expressed in terms of the Reynolds number for both laminar and turbulent flow.
On 1 April 1962 Heinrich Blasius celebrated his 50th anniversary in teaching.
One of his most notable contributions involves a description of the steady two-dimensional boundary-layer that forms on a semi-infinite plate that is held parallel to a constant unidirectional flow
First law of Blasius for turbulent Fanning friction factor: Second law of Blasius for turbulent Fanning friction factor: Law of Blasius for friction coefficient in turbulent pipe flow: