Whistling of corrugated pipes

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Wave induced growth and evaporation of droplets in a vapor-gas mixture

Heterogeneous condensation and evaporation induced by an unsteady rarefaction wave and by the passage of a shock wave in a water-nitrogen mixture is studied. Time resolved measurements of modal droplet radius, droplets radius, droplet number density, pressure, and gas density are presented. Condensation on Cr2O3-particles of about 10 nm starts at a saturation ratio of 3.4. Typical droplet radii and droplet number densities are 1.5 µm and 1011 m-3. A shock wave with Mach number 1.36 causes full evaporation in 4 ms

Dynamic measurements on an airfoil using acoustic forcing

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Dynamic measurements on an airfoil using acoustic forcing

Abstract only

An accurate experimental investigation of the shock-tube end-wall boundary layer in argon

A laser schlieren method is applied to measure the density-gradient profile of the shock-tube end-wall boundary layer in argon. From measurements at different positions the expected self-similar structure of the boundary layer is well established. Corrections are made for the effects of higher-order spatial derivatives of the density on the schlieren signal. The experimental boundary-layer structure is found to agree within an error bound of 2% with the theoretical calculation based on recent accurate thermal-conductivity data, if the variation of the pressure is taken into account

Flow-induced pulsations in double closed branch systems

Flow-induced pulsations are frequently observed in pipe networks, when the main ow passes along a number of closed branches. Although there have been detailed studies on the pulsations generated by the separating ow along a closed side branch, the configurations with the ow entering or leaving the side branch have not been extensively analyzed. In this study, strong ow-induced pulsations have been measured in configurations with a mean ow diverging into a side branch and entering the main pipe from a side branch. Pulsations amplitudes almost as strong as observed in con??gurations with closed side branches have been measured