Professor Flay studied Mechanical Engineering at the University of Canterbury, graduating BE (Mech) with 1st Class Honours in 1975. He then registered for his PhD at the same university and graduated in 1979 with a PhD in Wind Engineering. This was followed by a period of two years as a National Research Council Visiting Fellow at the Atmospheric Environment Service, Environment Canada, Toronto, where he worked with Dr Hans Teunissen, carrying out research in wind engineering using a Boundary Layer Wind Tunnel. He then moved to a consulting company in Toronto for a period of four years, where he was employed as an Aerodynamic Design engineer, and carried out design work on many different kinds of wind tunnels, both subsonic and supersonic.
Since returning to New Zealand, Professor Flay joined the Mechanical Engineering Department in 1984 as a senior lecturer. He has been Professor of Mechanical Engineering since 2000. He was appointed to Guest Professor at Tokyo Polytechnic University in 2008, and Guest Professor at Central South University in 2018. He was also the Chair of the 9th Asia Pacific Conference on Wind Engineering in 2017.
Professor Flay is Director of the Yacht Research Unit, which has a superb international reputation, and has carried out a large proportion of the world’s wind tunnel testing of yacht sails. A highlight was his design of the world’s first wind tunnel capable of producing twisted flow for testing yacht sails. This wind tunnel was used by Team New Zealand, and helped them win the America’s Cup in 1995 and 2017. A new closed circuit wind tunnel at the University's Newmarket Campus suitable for a wide range of aerodynamic investigations, with a test section 3.6 m wide and 2.5 m high has been designed and built, and was completed in June 2015. His research group is currently collaborating with a UK-based company and providing wind engineering advice on very tall buildings in the Middle East and elsewhere. This work has led their research in time-history approaches to determining the response of buildings with non-linear structural systems. He is currently undertaking exciting research on design wind speeds for New Zealand, wind excitation of buildings, roofs, and other structures, the wind environment around buildings for human comfort information and the aerodynamics of cyclists and skiers.