Icing Tests in a Small Blow-Down Wind Tunnel
G. P. Russo; A. Esposito, B. Esposito; R. Renis
F. De Rosa and F. Parente

Source FDMP: Fluid Dynamics & Materials Processing, Vol. 6, No. 3, pp. 319-336, 2010
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Keywords Icing wind-tunnel
Abstract A low-cost facility, able to simulate icing conditions occurring in flight, has been built via modification of a small blow-down supersonic wind tunnel. As the storage tank (30bar) is emptied through the wind tunnel, expansion of the contained air makes temperature to decrease down to -20 C and a control valve holds such temperature for about 200s. In order to increase the liquid water content (LWC) of the flow allowing ice formation on model surfaces within the test chamber, water is sprayed in the stream within the stagnation chamber by means of a controlled spray gun. This unsteady technique allows to work only at a peculiar Mach number at which the heating from the tank walls compensates the cooling due to expansion. Both an Icing Rotating Cylinder and an Icing Blade Technique have been used to measure the LWC in the stream. The Median Volumetric Diameter (MVD) of the supercooled water drops has been measured by both a Phase Doppler Particle Analyzer (PDPA) and an Oil Slide Technique. The measured values of the LWC ranged from 0,7 to 1,5 g/m3and those of the MVD ranged from 20 to 50mm in accordance with typical values encountered in flight within dangerous clouds.
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