Harry Ricardo

Sir Harry Ricardo (1885-1974) was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine. He patented the two-stroke engine design, personally developed the engines that would be used in the first tanks, oversaw the research into the physics of internal combusion that led to the use of octane ratings, was instrumental in development of the sleeve valve engine design, and invented the Diesel pre-combustion chamber that made high-speed diesel engines possible.

Harry Ricardo was born in London in 1885, and was one of the first people in England to see an automobile when his grandfather purchased one in 1898. He was from a wealthy family and educated at Rugby School. In 1903 he joined Trinity College, Cambridge as a civil engineering student.

In 1904, at the end of his first year, he decided to enter the University Automobile Club's event, which was a competition to design a machine that could travel the furthest on a quart (1 L) of petrol. His engine was the heaviest entered, but his motorcycle design nevertheless won the competition. He was then convinced to join the Professor of Mechanism and Applied Mechanics, Bertram Hopkinson, graduating with a degree in 1906.

Upon graduation Ricardo set up his own company, the Two Stroke Engine Company, in order to sell a small engine and car he called the Dolphin. Although they had some sales, notably for fishing boats, the company nevertheless failed in 1911.

He set up a new company in 1915, Engine Patents Ltd., which developed the engine that would eventually be used in the first successful tank design, the British Mark V. A total of over 8000 of his tank engines were put into military service, making it the first British-designed engine to be produced in large numbers.

In 1917 Bertram Hopkinson invited him to join the new engine research facility at the Department of Military Aeronautics, later to become the RAE. In 1918 Hopkinson was killed while flying a Bristol Fighter and Ricardo took over his position. From that point on the department produced a string of experimental engines and research reports that constantly drove the British, and world, engine industry.

One of his first major research projects was on the problems of pre-ignition, known as knocking or pinging. To study the problem he built a unique variable-compression test engine. This led to the development of the octane rating system, and considerable investment into octane improving additives and refining systems. The dramatic reduction in fuel use as a result of higher octane fuel was directly responsible for allowing Alcock and Brown to fly the Atlantic in their Vickers Vimy bombers adapted with his modifications.

Ricardo's work exerted influence all around the world. While his work guaranteed England a supply of fuels of ever-increasing power during the 1930s, it also enabled Germany to produce synthetic high-octane aviation fuel, for example for the Focke-Wulf Fw 190 inflicted heavy losses among the RAF's Supermarine Spitfires in 1942. Likewise, Ricardo's research on the detonation-inhibiting qualities of alcohol-water injection was exploited by German engineers to provide their aeroengines with a particularly powerful special emergency power rating.

Another late 20s-early 30s development was a new type of combustion chamber for diesel engines that allowed them to be run at high speed. The resulting design, known as the Comet, would go on to be used in a number of boats, trains, trucks as well as many World War II tank designs, including one of the same name.

Another major development effort was research into rotating-sleeve valve engines, which were widely used in the British airplane engine industry during the war. By the end of the war the Napier Sabre, based on his work, was the most powerful piston engine in the world at over 3,500 hp (2,600 kW). He was also instrumental in Napier's decision to build a diesel-compound engine with extremely good fuel economy, the Napier Nomad, although it was not a commercial success. Bristol Engines and Rolls-Royce also developed powerful sleeve valve engines, the later's Rolls-Royce Crecy remained the most powerful engine of its size for many years after the war, at over 200 bhp/litre (150 kW/L).

After the war he started Ricardo Consulting Engineers, which has become one of the foremost automotive consulting firms worldwide.

During the 1960s a second round of development of the Comet system was started, now armed with considerably more powerful test apperatus. The refined design was immediately used in several cars, and the pre-combustion system remains in use in most diesel engines today. Ricardo Consulting remains committed to the diesel, considering it to be nowhere near its development potential even in the most advanced of today's engines.

In 1978 the US Department of Energy hired Ricardo Consulting to research the Stirling engine as a car engine. A series of engines, eventually forty-five in total, were built to test this system and showed very low emissions, but the efficiency was compromised by the need to operate under transient conditions -- the design was best running at a single speed, making it less than useful as a car engine. The Stirling may make an excellent engine for hybrid cars and has recently generated some interest in this role.

In 1986, the Rutan Voyager was the first aircraft to fly around the world non-stop and without refuelling. Ricardo Consulting redesigned the otherwise "stock" Teledyne Continental engine to incorporate a highly efficient combustion system and water cooling, thereby dramtically reducing drag and improving fuel economy.

Ricardo had long worked on direct injection gasoline engines as well as diesel, work that finally started to come o fruition in the 1990s. Today several stratified charge engines are in use in the automobile market, designs that would not have existed without his constant work on them.

Ricardo was elected Fellow of the Royal Society in 1929, and in 1948 was knighted. He died in 1974 at the age of 89.

External links

Sir Ricardo?s Description of Combustion in Diesel Engines (http://www.me.berkeley.edu/ME140/lab/Sir_Ricardo.pdf)