RU2716650C1 - Pulse resonator ejector - Google Patents

Abstract

FIELD: jet equipment.

SUBSTANCE: invention relates to jet engineering, particularly, to gas ejectors. Ejector comprises an underwater channel, a mixing chamber, a vacuum chamber with a slit connecting it with the gas bleed zone, an outlet diffuser and a cavity and a resonator tube installed between the underwater channel and the mixing chamber, which together form a resonator.

EFFECT: invention increases the ejection ratio by 2–2,5 times.

1 cl, 3 dwg

Description

The invention relates to inkjet technology, and in particular to gas ejectors and can be used in the industrial industry for pumping gases, dusty air mixtures in dustproof devices, in heating, ventilation and air conditioning systems, as well as in aviation in aircraft flow control systems (LA) at subsonic and transonic flight speeds.

To control the flow around the wing of an aircraft with a view to its reconstruction in a favorable direction, devices (actuators) of various types are used. As a rule, these devices in one way or another form a gas stream, which can be directed into sensitive flow zones and cause its rearrangement in a favorable direction.

A known actuator operating on high-pressure gas, using a special pneumatic device, generates pulsating blowing in one flow region and constant suction of the boundary layer in another: Arwatz, G., Fono, I., and Seifert, A. "Suction and oscillatory blowing actuator modeling and validation, "AIAA journal, Vol. 46, No. 5, 2008, pp. 1107-1117. The main disadvantage of such actuators is the need to select high pressure gas from the engine or from a special compressor.

The closest analogue adopted for the prototype is an ejector-type pulsed plasma thermal actuator (RF patent No. 2637235), consisting of an underwater channel, a check valve, an ejector nozzle, a mixing chamber, a vacuum cavity, an output diffuser and a discharge chamber with built-in needle electrodes, this rarefaction cavity is made with a slit connecting it to the surface of the wing.

A disadvantage of the known actuator is the need for a high-voltage switching power supply of significant power in the control system.

The objective and technical result of the present invention is to increase the coefficient of gas ejection, simplify the circuit of the device, significantly reduce energy costs, increase the efficiency in the consumption of high-pressure gas.

The solution of the problem and the technical result is achieved by the fact that the pulsed resonator ejector containing an underwater channel, a mixing chamber, a rarefaction cavity with a slit connecting it to the gas extraction area and an output diffuser further comprises a cavity and a resonator tube installed between the underwater channel and the mixing chamber, forming jointly resonator.

The figure 1 shows a diagram of a resonant pulse ejector.

The figure 2 shows the results of experimental bench studies of the dependence of the volumes of ejected gas during operation of the ejector in stationary and pulsed modes, depending on the flow rate of high-pressure gas.

The figure 3 shows a graph of the values of the coefficient of ejection for different modes of operation of the ejector.

The pulsed resonator ejector (Fig. 1) consists of a path for supplying high-pressure pulses 1, a resonator consisting of a cavity 2 and a resonator tube 3, a vacuum cavity 4, into which the external medium is sucked through slit 5, and a mixing chamber 6, which passes into the output diffuser 7.

The principle of operation of a pulsed resonator ejector is as follows: overpressure pulses with a certain duty cycle are applied to the input of a pulsed resonator ejector along path 1. The shape of the pressure pulses and the duty cycle are of no fundamental importance (the laboratory sample was tested with pressure pulses similar in shape to positive sinusoidal, and duty cycle equal to three). During a positive pressure pulse, high-pressure gas flows. As a result, intrinsic pressure fluctuations (both positive and negative) of a certain amplitude arise in the cavity of the resonator 2 and the resonator tube 3, depending on the quality factor of the resonator. In this case, a reciprocating gas flow occurs in the resonator tube 3. Progressive (blowing) during the passage of a positive pressure impulse and return during between pulses. The resonator tube 3 is simultaneously a high-pressure nozzle of the ejector. During the outflow of gas from the nozzle, the ejector creates a vacuum in the chamber 4 and the gas is sucked out from the gas extraction area through the slot 5. During the gas backflow into the tube 3, gas is also sucked from the chamber 4 and from the gas extraction area through the gap 5. Thus, gas suction through slit 5 occurs continuously both during a positive pressure pulse during which the high-pressure gas flows and in the interval between pulses when the high-pressure gas flows equal to zero. This causes a significant decrease in the flow rate of high-pressure gas and an increase in the ejection coefficient.

When using a pulsed resonator ejector as a device for controlling the flow around the wing in cruising modes, the gas sampling area is the outer surface of the wing.

The presence in the design of the resonator pulse ejector resonator, provides increased efficiency design for the flow of high-pressure gas.

The main experimentally determined resonant frequency for the studied ejector design was f≈60 Hz. It can be seen that the pulsed mode of operation at frequencies far from resonance (“Non-resonant pulsed mode of 40 Hz” in Fig. 2) already provides significant savings in the flow of high-pressure gas necessary to achieve a given ejection rate. The resonant operation mode of the ejector (“Resonant pulse mode 60 Hz” in Fig. 2) increases its productivity in the flow rate of the ejected gas by another 20-25%.

The ejection coefficient (Fig. 3), which is equal to the ratio of the mass flow rates of the ejected and high-pressure gases, also increases significantly with pulsed modes of the ejector, even at frequencies far from resonance.

In resonance mode, the ejection coefficient is 2-2.5 times higher than in stationary mode. The most effective resonant modes of the ejector at small and medium flow rates of high-pressure gas.

Claims (1)

A pulsed resonator ejector containing an underwater channel, a mixing chamber, a rarefaction cavity with a slit connecting it to the gas extraction region, and an output diffuser, characterized in that it further comprises a cavity and a resonator tube installed between the underwater channel and the mixing chamber, forming a joint cavity.

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