CN108019292B

CN108019292B - Vibration reduction method for jet nozzle flow guide fin

Info

Publication number: CN108019292B
Application number: CN201610961275.0A
Authority: CN
Inventors: 闻洁; 徐国强; 张铎
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2016-11-04
Filing date: 2016-11-04
Publication date: 2020-04-28
Anticipated expiration: 2036-11-04
Also published as: CN108019292A

Abstract

The patent discloses a vibration reduction method for a guide fin of an injection nozzle, and belongs to the technical field of aviation propulsion. This patent adds a series of damping holes on original injection spray tube water conservancy diversion fin to the air pressure of balanced water conservancy diversion fin both sides can effectively reduce the vibration of injection spray tube in the use. The jet nozzle is simple to operate, can effectively reduce the vibration of the jet nozzle in the use process and ensure the normal operation of the jet nozzle only by punching the guide ribs according to a certain rule without adding an additional structure, reducing the strength of the guide ribs and influencing the normal operation of the jet nozzle, and has better practical value and wide application prospect in the technical field of aviation propulsion.

Description

Vibration reduction method for jet nozzle flow guide fin

Technical Field

The invention relates to a vibration reduction method for a jet nozzle flow guide fin, and belongs to the technical field of aviation propulsion.

Background

The jet nozzle flow guiding fin is usually arranged in an annular flow channel between a main jet pipe and an outer sleeve of the jet nozzle, so that backflow can only flow according to a certain specific flow path, the backflow flow is reduced, and the influence on the flow rate of the jet nozzle is small; therefore, the engine can be prevented from sucking the backflow tail gas, and the normal work of the engine in the starting process is ensured. In the presence of reflux: the structure reduces the flow area of the backflow, and an expansion channel is formed to reduce the flow rate of the backflow, so that the backflow is stagnant near the inlet of the injection spray pipe, and the normal work of an engine and an accessory system is guaranteed. Under the normal condition of drawing and leading to penetrate: the structure enables the injection airflow to be mixed with the main flow gas at an inclined angle, so that the injection airflow and the main flow gas are fully mixed, and the exhaust temperature of the injection spray pipe is reduced. However, because the flow velocity of the air flow at the position of the jet nozzle is high, the high-speed air flow flows along the specific flow path, so that the flow guide fins vibrate and influence the main nozzle and the outer sleeve of the jet nozzle, the normal operation of the jet nozzle is influenced, and the service life of the jet nozzle is shortened.

Disclosure of Invention

1. The purpose is as follows: in view of the above problems, the present invention aims to provide a vibration reduction method for the guide fin of the ejector nozzle, which can effectively reduce the vibration of the ejector nozzle during the use process and ensure the normal start of the engine and the normal operation of the accessory system without adding an additional structure, ensuring a certain strength of the guide fin, and affecting the normal operation of the ejector nozzle.

2. The technical scheme is as follows: the technical scheme adopted by the invention is as follows: a series of vibration reduction holes are added on the original jet nozzle flow guide rib, so that the vibration of the jet nozzle in the using process can be effectively reduced.

3. The advantages and the effects are as follows: the invention has the beneficial effects that: the operation is simple, only holes are punched on the guide ribs according to a certain rule without adding an additional structure, certain strength of the guide ribs is ensured, normal work of the injection spray pipe is not influenced, vibration of the injection spray pipe in the use process can be effectively reduced, and normal work of the injection spray pipe is ensured.

Drawings

FIG. 1 is a typical ejector nozzle configuration with guide fins.

FIG. 2 shows the main nozzle and the guide ribs after the holes are punched.

Fig. 3 is a top view of fig. 2.

In the figure, 1 is an outer sleeve, 2 is a main nozzle, 3 is a diversion rib (first row), 4 is a diversion rib (second row), 5 is a perforated diversion rib (first row), and 6 is a perforated diversion rib (second row).

Detailed Description

The invention is further described with reference to the following drawings and detailed description.

As shown in fig. 1, a typical jet nozzle configuration. The invention does not change the basic structure and the size of the injection nozzle, but improves on the basis.

As shown in fig. 2 and 3, the improved jet nozzle structure (the outer sleeve is omitted to better show the position of the hole on the guide fin). On the basis of the figure 1, the guide rib is provided with a series of damping holes, so that the pressure of airflow on two sides of the rib can be balanced on the premise of ensuring the strength of the rib, the rib vibration generated by airflow excitation is reduced, and the normal work of the injection spray pipe is ensured.

The front part of the first row of fins is parallel to the airflow direction, and the fins are larger, so that more holes can be formed in the front part, the aperture can also be larger, the pressure of the airflow on the two sides of the fins can be better balanced, and a certain weight reduction effect can be achieved. The middle part of the first row of fins is almost vertical to the airflow direction and is not mutually shielded with the second row of fins, more holes are punched at the position to increase the backflow flow rate and influence the normal work of the flow guide fins, and therefore holes are not punched or a small number of holes with smaller apertures are punched at the position to balance the airflow pressure at the two sides of the fins. The rear part of the first row of fins and the second row of fins are in a mutually shielding state along the axial direction, so the punching positions of the two positions are mutually coordinated, the hole rows on the two fins are in a staggered arrangement form when viewed along the axial direction so as to reduce the backflow flow, the hole diameter of the punching is smaller, and the punching number can be properly adjusted under the condition of ensuring the strength of the fins so as to better balance the airflow pressure on the two sides of the fins.

The holes on the fins can be processed after the fins are manufactured, the number of the holes can be adjusted according to the vibration condition of the injection spray pipe, and certain fin strength needs to be guaranteed.

Claims

1. A vibration reduction method for a guide fin of an injection nozzle is characterized in that a series of vibration reduction holes are added on the guide fin of the original injection nozzle to reduce the vibration of the injection nozzle in the use process: a series of vibration reduction holes are added on the guide fin of the original injection spray pipe according to a certain rule so as to balance the airflow pressure at two sides of the guide fin and reduce the vibration of the injection spray pipe in the use process; the guide fins comprise a first row of punched guide fins and a second row of punched guide fins, the front parts of the first row of punched guide fins are parallel to the airflow direction, holes are formed in the positions, the middle parts of the first row of punched guide fins and the second row of punched guide fins do not form mutual shielding and do not punch, the rear parts of the first row of punched guide fins and the second row of punched guide fins are in a mutual shielding state along the axial direction, and the holes in the rear parts of the first row of punched guide fins and the holes in the second row of punched guide fins are in a staggered arrangement form when viewed along the axial direction; the aperture of the upper hole at the front part of the first row of punched guide fins is larger than that of the upper hole at the rear part of the first row of punched guide fins.