John R. Womersley

John Ronald Womersley (20 June 1907 – 7 March 1958) was a British mathematician and computer scientist who made important contributions to computer development, and hemodynamics. Nowadays he is principally remembered for his contribution to blood flow, fluid dynamics and the eponymous Womersley number, a dimensionless parameter characterising unsteady flow.

Biography

Early life and education Womersley was born on 20 June 1907 in Morley, near Leeds in the West Riding of Yorkshire. He was the only child of George William and Ruth Womersely; his father managed a grocery store in Morley. He was educated at Morley Grammar Schoo l from 1917 to 1925. In 1925 he was awarded an Open Scholarship to the University of Cambridge and the Royal Scholarship in Physics at Imperial College of Science and Technology, but he chose to read mathematics at Imperial College. the use of mathematical statistics in industrial production and quality control. This organization was responsible for advice and research into ammunition supply, engineering factories and the investigations of a range of Government Inspectorates. It was particularly important in ensuring quality control and promoting sample inspection methods to British industry during wartime. In 1944 he joined the British Association mathematical tables committee and in the same year he was appointed as the first superintendent of the Mathematics Division of the National Physical Laboratory (NPL). In addition to being responsible for statistical quality control, NPL was tasked with building an electronic computer, for which Womersley coined the name Automatic Computing Engine (ACE), echoing Babbage's Analytical Engine. Womersely was therefore responsible for the set up and operation of the first national computing centre in UK. One of his first actions was to visit the US for a fact-finding tour, where he learned about ENIAC (Electronic Numerical Integrator and Computer), Howard Aitken's Harvard machine, George Stibitz's machines and von Neumann's plans for the binary computer, EDVAC (Electronic Discrete Variable Automatic Computer). On his return, he recruited Alan Turing to work on the ACE section and backed him strongly. Womersley also recruited Donald Davies in 1947. However, progress on the ACE project was delayed and Turing developed a dislike of Womersley and disdain for his abilities and left the project in 1948. Davies then took over from Turing and a small experimental model, pilot ACE was produced in 1950. Whether Womersely led NPL successfully has been questioned, although the consensus seems to be that he did a good job in difficult circumstances. He himself left the project in 1950, before the prototype pilot ACE was completed, to join the British Tabulating Machine Company (BTM), a forerunner of International Computers Limited (ICL). There he recognised that the computers previously developed by academia or governments were too large and expensive to be commercially viable and he recruited Andrew Booth who had developed the All Purpose Electronic Computer at Birbeck University, as a consultant to develop a smaller inexpensive computer. The computer copied from Booth's original design by Ray Bird was named the Hollerith Electronic Computer (HEC1), and was Britain's first mass-produced business computer.

In 1954 Womersley left BTM and joined a research team, led by Donald McDonald at St Bartholomew's Hospital, who were studying blood flow in arteries. This change seems to have been a temporary arrangement to 'fill in time whilst awaiting completion of arrangements to come to WADC' (the Wright Air Development Center, Dayton, Ohio, USA). Whatever the reason, this move led to a new and highly productive period in his research, as he applied mathematical and computational techniques to the analysis of blood flow and hemodynamics. Most notably in 1955 he published an article which described a dimensionless parameter (α) which characterised the nature of unsteady flow; subsequently this has been called the Womersley number.