Philip Gerald Drazin (25 May 1934 – 10 January 2002) was a British mathematician and a leading international expert in fluid dynamics.
After leaving Cambridge, he spent two years at MIT before moving to the University of Bristol, where he stayed and became a Professor until retiring in 1999.
Drazin worked on hydrodynamic stability and the transition to turbulence.
His 1974 paper On a model of instability of a slowly-varying flow introduced the concept of a global mode solution to a system of partial differential equations such as the Navier-Stokes equations.
In 1998 he was awarded the Symons Gold Medal of the Royal Meteorological Society.