SPECIAL GAS EJECTOR GEOMETRIES – EFFECTS AND APPLICATIONS

• Main Authors: Bogdan Diaconu, George Șerban, Viorel Crăciunescu
• Format: Article
• Language: English
• Published: Editura Academica Brâncuşi 2019-11-01
• Series: Analele Universităţii "Constantin Brâncuşi" din Târgu Jiu: Seria Inginerie
• Subjects: ejector; spindle; oscilatory flow; noise; vibration
• Online Access: http://www.utgjiu.ro/rev_ing/pdf/2019-3/07_BOGDAN%20DIACONU,%20GEORGE%20%C8%98ERBAN,%20VIOREL%20CR%C4%82CIUNESCU%20-SPECIAL%20GAS%20EJECTOR%20GEOMETRIES%20%E2%80%93%20EFFECTS%20AND%20APPLICATIONS.pdf

Gas/vapor ejectors are widely used in various applications due to significant advantages over other devices used to raise the momentum of a gas. The main application of ejectors is pumping (increasing pressure) of a low pressure fluid by taking advantage of the depression caused by expansion of a high pressure fluid – motive fluid. Low energy efficiency of the process is the main disadvantage of the ejector technology. The geometry of the device, fluid thermo-physical properties and parameters influence the efficiency of the entrainment process. The ejector consists of three main parts, primary nozzle, mixing chamber and diffuser. Although a simple device, the flow in an ejector system is complex and difficult to model in some respects. Supersonic flow in ejectors resulting from expansion of the motive fluid in the nozzle creates the chocking condition that limits the maximum value of the entrained flow. The paper explores by means of CFD a non-conventional ejector geometry which can be used to reduce the oscillations that occur in the mixing chamber after the outlet of the primary nozzle. The new element proposed in this paper is a conic spindle placed axi-symmetrically in the diffuser region.