The Utilization of Specially Tailored Air Bubbles as Static Pressure Sensors in a Jet

Abstract

It is shown that air bubbles of a certain size may be used to measure the fluctuating pressure in a liquid jet. The conditions under which these bubbles accurately reflect the local static pressures are described in detail; the volume shape of the bubbles was determined by holography for a 3.17 mm jet and the change in volume is interpreted as a result of the fluctuating pressure. The experimental results revealed that at any one instant, a wide spectrum of static pressure fluctuation intensities exist in the jet. It was also found that the probability distribution of these intensities has a slightly skewed bell shape distribution and that the fluctuating static pressure peaked at a higher positive value than a negative one.