Osborne Reynolds FRS (/ˈrɛnəldz/; 23 August 1842 – 21 February 1912) was a prominent innovator in the understanding of fluid dynamics. Separately, his studies of heat transfer between solids and fluids brought improvements in boiler and condenser design. He spent his entire career at what is now called University of Manchester.
Osborne Reynolds was born in Belfast and moved with his parents soon afterward to Dedham, Essex. His father worked as a school headmaster and clergyman, but was also a very able mathematician with a keen interest in mechanics. The father took out a number of patents for improvements to agricultural equipment, and the son credits him with being his chief teacher as a boy. Osborne Reynolds attended Queens' College, Cambridge and graduated in 1867 as the seventh wrangler in mathematics. In 1868 he was appointed professor of engineering at Owens College in Manchester (now the University of Manchester), becoming in that year one of the first professors in UK university history to hold the title of "Professor of Engineering". This professorship had been newly created and financed by a group of manufacturing industrialists in the Manchester area, and they also had a leading role in selecting the 25‑year‑old Reynolds to fill the position.