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THE HEAT BARRIER
Few people know it, but CONCORDE, employ lot of ingenuity in order to overcome the difficulties of a supersonic flight.
Indeed, CONCORDE is large (62,19 meters - 202.61 feet), rapid (Mach 2.02) transports approximately a hundred and twenty people, this involves the deformations of structure and the rises in consequent temperatures.

127° =260°F | 91° =196°C
To 11 miles(NOTE : 1,5 english = 1.5 US | For example 1,5*2=3) of altitude and 1 364 miles/hours,
Concorde grows of 9.44 inch .


It is with an aerodynamic preoccupation of profit and a profit of weight that one decided ' to drown ' the fuselage in the wing, and thus to build the two sets of only one holding. The sections of fuselage will include departures of aerofoil thus, a single construction at the time for a plane of this size. The structural problems to solve were indeed considerable for such a thin plane, therefore deformable, undergoing moreover a notable heating.
For a plane of 202 feet length and 84 feet scale, with an aera of 3856 sq ft, the surface of the mitres being deducted, the estimate of weight, 185 tons, can surprise. Approximately 50% of the mass will be devoted to the fuel. It is seen that the remainder will have to be very light. On this point, the engineers count on material chosen for the structure and the coating: a refractory aluminium alloy named AU2GN. It has only one defect : that to age a little quickly. But it fights much better the ' heat barrier '. A Mach 2.2, friction will heat the point of the nose with 356° F, the leading edge with 311°F, the fuselage and the trailing edge of the aircraft between 284°F and 302°F. Taking into account the ambient cold at high altitude (-122°F/ -131°F), the temperature of surface will be about 257°F/ 266°F, high for traditional alloys. In the absence of AU2GN, it would be necessary to employ titanium, but this metal is heavier and also more difficult to work.
The AU2GN is not a ' prototype ' alloy. It is used already for the paddles of engines at considerable motor mechanics. It will be adopted without much discussion by the partners of Concorde.

Original article: Science & Vie N°9 - June 1992.