Spray pipe for ejector, ejection unit and air ejector

Abstract

The invention discloses a spray pipe for an ejector, an ejection unit and an air ejector. The spray pipe is horn-shaped and comprises a large-diameter end and a small-diameter end; an annular airflowstanding chamber is arranged in the pipe wall of the spray pipe in the circumferential direction of the spray pipe, an opening is formed in the side, facing the small-diameter end, of the annular airflow standing chamber, and the opening extends to the end face of the small-diameter end. A plurality of air inlets are formed in the large-diameter end of the spray pipe in the circumferential direction of the spray pipe, and each air inlet is connected to the annular airflow plenum chamber through an air inlet channel formed in the pipe wall of the spray pipe. According to the invention, the contact area of the injected airflow and the injected airflow can be increased, the pressure loss is reduced, and the mixing efficiency and the pressurization ratio are improved.

Description

technical field [0001] The invention belongs to the technical field of wind tunnels, and more specifically relates to a nozzle pipe for an ejector, an ejection unit and an air ejector. Background technique [0002] In the existing wind tunnel technology, there are mainly three types of ejector structures: central ejector, annular ejector and multi-nozzle ejector. [0003] Figure 1A It is the cross-sectional view of the mixing chamber inlet of the central ejector, and an ejecting nozzle 8 is installed in the pipeline center of the ejecting pipe 7, and the ejecting air flow is sprayed into the mixing chamber along the axial direction of the ejecting pipe 7 by the ejecting nozzle 8, The ejected airflow flows into the mixing chamber from around the ejector nozzle 8; this arrangement makes the ejected airflow near the wall of the ejector pipe 7 a low-speed ejected airflow, and the friction loss is small, but the airflow is unevenly mixed, and it is desired to achieve full mixing...

AI Technical Summary

Problems solved by technology

Due to its unique advantages, the multi-nozzle ejector has been more and more widely used. Most of the modern designed wind tunnels adopt the multi-nozzle ejector method, but this type of ejector, the ejector nozzle and the The structure of the ejected airflow channel is complex, and the design and processing are difficult, and multiple ejector nozzles are placed in the ejected airflow channel, which will cause a large energy loss to the ejected airflow

In addition, studies have shown that if the multi-nozzle ejector is improperly designed, the supersonic ejection airflow at the outlet of the multi-nozzle will collide with each other, which will aggravate the pressure loss

[0006] In addition to the above three ejectors, there is also a differential ejector in the prior art, which is a theoretical infinite multi-stage ejector. The application model of this ejector adopts the peripheral layout nozzle method to obtain a higher pressurization ratio, but the data show that with this ejector structure, only under a small diameter, the jet airflow in the ejector pipe can achieve effective mixing with the ejector airflow, and, in order to achieve For nozzle jets with different Ma numbers, dozens of nozzles need to be installed along the axial direction of the ejector pipe. The structure is complex and the processing is difficult. It is difficult for differential ejectors to be widely used in large-diameter wind tunnels.

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