AERODYNAMICS ADD-ON, THE MIGHTY HISPANO-SUIZA BLOWER!

This article is an add-on to ‘GO WITH THE AIR-FLOW, THE AERODYNAMICS OF A ZEPPELIN…’

Some time ago I found photo’s of the Hispano-Suiza windtunnel – the so-called ’Soufflerie’ – at Bois-Colombes, a suburb of Paris. This week is a good moment to publish an article about this subject as an add-on to the aerodynamics article of last weekend!

The mighty Hispano-Suiza blower building in Bois-Colombes was built in 1936-1937 to test aircraft engines. This French “Heritage of the twentieth century” is a unique witness to the time when the aviation industry was booming in western Paris. Since 2000 the building is classified as a historic monument and now houses the public school Ecole la Cigogne.

Hispano-Suiza had started out at the beginning of the 20th century as a car manufacturer at Barcelona, Spain, producing automobile chassis (they did not produce their own coachwork), designed by their talented Swiss engineer Marc Birkigt.

In 1911 the company opened its first French factory in Levallois-Perret. This part of Paris had been hometown to many other car-brands at that time, like Dion-Bouton, Renault, ect. To cope with the development of its expanding activities, Hispano-Suiza moved to Bois-Colombes in 1914.

Fuelled by the huge demand for aero engines during the Great War (WWI), Birkigt developed a revolutionary V8 aero engine which was to become a key in the victory of the Allies. This engine was so successful that many licenses were given to other manufacturers around the world. Total production of the V8 engine during WW1 was 49,893 units, a world record that would stay for many years. It was the flying stork emblem of the successful squadron of the flying ace Captain Georges Guynemer, which later became the symbol and emblem for the Hispano-Suiza company and its automobiles.

From the middle of the 1930s, new war efforts caused the company to focus entirely on aeronautical and military activities and to permanently abandon automobile production.

After a period punctuated by success both in the aviation and automotive, Hispano-Suiza came under state control in 1936 and its production is shifted entirely to military aviation and armament, totally abandoning automobile production. The “Soufflerie’ was built the following year to test aero engines, fuselages and airplane propellers, all life size. The building measures 55 meters long and 16 meters wide. The principle is simple: through 16 fan blades of 8 meters in diameter, driven by a powerful electric motor, a collector funnel captures the outside air and brings it into the testing chamber at a rate which can reach 325 km/h. At that speed the windtunnel would suck up a huge 100,000 m3 of air per minute!

Via a diffuser the windtunnel would then evacuate the air through an anti-vortex filter at the rear of the building. During the German occupation of Paris the blower is hardly used, except during the Allied bombing of 1943, when the Germans sometimes turn it on to show the Allies that the plant is still working.

The ’Soufflerie’ is still used in the early 1950s for testing new jet engines, but is permanently stopped in 1953, notably under pressure from local residents who complained about the terrifying noise, especially during testing at night. A portion of the interior is then destroyed and converted into offices. Since then, the tunnel has remained the symbol of the epic Hispano-Suiza company.

Snecma, which had taken control of Hispano-Suiza in 1968, decided to completely close the Bois-Colombes site in 1995. Four years later, the last employees left the factories, most machines having already been transported to Gennevilliers by then. The registration of the blower as a historical monument will ensure that the unique character of its facades is preserved.