Philipp Forchheimer (7 August 1852 – 2 October 1933) was an Austrian engineer, a pioneer in the field of civil engineering and practical hydraulics, who also contributed to the archaeological study of Byzantine water supply systems. He was professor in Istanbul, Aachen, and Graz.
In 1891, he took up a parallel appointment in Constantinople at the Ottoman School of Engineering, which he successfully re-organised in 1914. His work in Turkey led to a study of the Byzantine cisterns with the archaeologist Josef Strzygowski. In 1897 or 1898, he spent a month researching aqueduct systems at the Austrian excavations in Ephesus.[2][3]
Modification to Darcy's Law
Forchheimer proposed a modification to Darcy's Law, describing fluid flow through packed beds in 1901. This also had a significant influence on the development of the Ergun equation.[4]
where:
is the pressure drop across the bed, is the viscosity of the fluid, permeability (const.), is the (area-averaged) velocity of the fluid, is an empirical constant, is the density of the fluid.
A more general expression of the friction factor follows from Forchheimers modification:[4]