Static pressure measurement along the centerline of an induced flow ejector

Conclusion The static pressure measuring system described in this paper is simple and does not disturb the flow perceptibly. Compared to wall pressure taps, the present measuring system has the advantage of being able to measure the static pressure at any section of the nozzle and to provide a continuous distribution, if necessary. An arrangement using a large number of wall pressure taps can be avoided.In addition, this system allows the internal static pressure of the flow to be measured, which is particularly interesting in the case of two coflowing streams inside an induced flow ejector. The primary jet can be investigated downstream of the primary nozzle exit plane. The static pressure at this exit plane, which is of great importance in numerical simulation of flows in ejectors, can be directly measured by means of this pressure probe (Lu 1986). This system also permits the detection of shock waves in the supersonic stream and gives accurate information about their location, their strength and the lengths of the disturbed areas. Hence, this system is useful for shock structure investigation, especially when flow visualization techniques are impossible to apply (non-transparent walls).However, the use of this measuring system is restricted to relatively short ejectors in order to limit the length of the capillary tube (less than 1.50 m in these experiments) and to minimize its oscillations in the flow.