GB720466A - Improvements in or relating to wind tunnels - Google Patents

Abstract

720,466. Wind tunnels. ROLLS-ROYCE, Ltd. March 21, 1952, [Dec. 22, 1950], No. 31307/50. Class 4. The flow of working fluid through a wind tunnel is caused by the exhaust of one or more gas turbines 10 set upstream of the working section 23 of the tunnel, and consists wholly or substantially wholly of the exhaust flow from said turbines. The exhaust duct of the engine is jointed at 14 to a divergent section 15, itself jointed at 19 to section 20 having a throat 21 and leading to a working section 23 of constant or slightly divergent exhaust section 24, or, for supersonic work, a second throat. Joint 14 is shown in section in Fig. 3; glands 13a on section 13 bolted to the engine exhaust duct sliding to allow longitudinal expansion, and member 16 sliding inside members 18 and 17, the latter being secured to section 15, allowing for misalignment of the engine. Joint 19 is similar, but without provision for expansion. The throat and working sections 21 and 23 are surrounded by heat retaining panels 32 of asbestos sandwiched between aluminium plates, the inner facing plate being polished. Heaters, preferably electric, are situated between these panels and the wind tunnel itself, and are employed to raise gradually the temperature of the enclosed sections prior to starting the turbine, thus eliminating thermal distortion due to the hot exhaust. A portion of the working section and the exhaust section may be slidable on wheels, to allow easy access to the test model.