CN110905686A

CN110905686A - Multi-flow-path combined engine starting protection structure

Info

Publication number: CN110905686A
Application number: CN201911046093.0A
Authority: CN
Inventors: 何学刚; 杜鹏程; 陈操斌; 侯泽兵; 马同玲
Original assignee: Beijing Power Machinery Institute
Current assignee: Beijing Power Machinery Institute
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2020-03-24

Abstract

The invention discloses a multi-flow-path combined engine starting protection structure, and belongs to the technical field of combined engines. The protection structure is a baffle arranged on the end surface of the outlet of the tail jet pipe of the bypass ramjet engine, the baffle is connected with the tail jet pipe of the bypass ramjet engine through a connecting mechanism and completely seals the outlet of the tail jet pipe, and after the turbine engine is started, the baffle blocks reverse backflow gas to prevent the gas from flowing back to the turbine engine through the bypass ramjet engine; after the bypass ramjet is normally started, the air flow in the channel of the bypass ramjet forms positive flow, and the connecting mechanism of the baffle falls off in an active or passive mode. The invention can avoid injecting and sucking high-temperature tail gas in the starting process of the engine, thereby meeting the structural safety in the zero-speed starting process of the multi-runner combined engine.

Description

Multi-flow-path combined engine starting protection structure

Technical Field

The invention belongs to the technical field of combined engines, and particularly relates to a protection structure for preventing gas backflow when a multi-runner combined engine is started at zero speed.

Background

The reusable aerospace transportation system provides high requirements for a power system such as horizontal take-off and landing, extremely wide speed domain and extremely wide airspace working, high specific impulse, high thrust, compact structure, light weight, reusability and the like, and the conventional turbine, ram and rocket engines and other single powers cannot meet the requirements at present, and the air-breathing combined engine is a necessary trend.

The air-breathing combined engine is formed by organically combining two or more types of turbine engines, stamping engines and rocket engines through structure, thermodynamic cycle and working process, can exert the advantages of engines of different types, has the characteristics of wide working package and good economy, and is ideal power for a hypersonic aircraft and an aerospace aircraft in a near space of horizontal take-off and landing.

The combined power reusable space transport system has the typical characteristics of convenient horizontal take-off and landing, free space entering and exiting, ground returning according to requirements and high-frequency reuse, can greatly reduce the launching cost and support large-scale space development.

A typical combined engine configuration is shown in fig. 1, where a plurality of bypass ramjets are arranged circumferentially around the turbine engine, the passages of the bypass ramjets themselves and the passages of the turbine engine itself forming a multi-flow passage combined engine. The zero-speed starting of the multi-runner combined engine is initiated by the work of the turbine engine, at the moment, the bypass ramjet is in an ignition closing state, and the bypass ramjet works in an ignition mode under the high Mach number.

The air flow direction of the combined engine at zero-speed starting is shown in figure 2, firstly, the turbine engine is started at zero-speed ignition, the air compressor rotates to suck air to perform combustion work and flow through a channel of the turbine engine, and at the moment, the channel of the bypass ramjet engine is in a free flow state. Due to the pumping action of the turbine compressor, combustion tail gas of the turbine engine flows back to the compressor inlet of the turbine engine through the bypass ramjet engine; high-temperature gas is sucked from the bypass ramjet, which can damage parts such as the bypass ramjet, the turbine compressor and the like or bring adverse effect to the work of the turbine engine.

Disclosure of Invention

In view of this, the invention provides a multi-flow-path combined engine starting protection structure, which can prevent high-temperature tail gas from being injected and sucked in the engine starting process, so that structural safety in the zero-speed starting process of the multi-flow-path combined engine is met.

A multi-flow path combined engine starting protection structure is a baffle plate arranged on the end face of an outlet of a tail jet pipe of a bypass ramjet engine, the baffle plate is connected with the tail jet pipe of the bypass ramjet engine through a connecting mechanism and completely seals the outlet of the tail jet pipe, and after a turbine engine is started, the baffle plate blocks reverse backflow gas to prevent the gas from flowing back to the turbine engine through the bypass ramjet engine; after the bypass ramjet is normally started, the air flow in the channel of the bypass ramjet forms forward flow, and the connecting mechanism of the baffle falls off in an active or passive mode.

Furthermore, the connecting mechanism is a bolt or an explosive bolt, when the baffle is connected with the tail nozzle of the bypass ramjet by the bolt, the baffle falls off in a passive mode, a weak groove is machined in the connecting part of the baffle, and the rest parts of the baffle are attached to the end face of the tail nozzle of the bypass ramjet and are not connected; when the baffle plate is connected with the tail nozzle of the bypass ramjet through the explosion bolt, the baffle plate falls off in an active mode, the explosion bolt detonates under the control of an external instruction, and the baffle plate is separated from the tail nozzle of the bypass ramjet.

Furthermore, the weak groove on the baffle is positioned on the end face opposite to the incoming flow, and the weak groove is V-shaped.

Has the advantages that:

1. according to the invention, the baffle is arranged on the end surface of the outlet of the tail nozzle of the bypass ramjet engine, so that high-temperature gas is prevented from being injected and sucked by the turbine engine, and the safety of the engine starting process is protected when the engine is started at zero speed; when the speed is increased, the bypass engine is conducted to normally work after the airflow of the bypass is smooth, so that the bypass engine normally works.

2. The invention adopts two modes of bolts or explosive bolts to respectively realize the passive falling or the active falling of the baffle plate, the separation structure is simple and reliable, and the selection can be carried out according to the actual working requirement.

3. The grooving position of the weak groove is arranged on the end face of the baffle plate opposite to the incoming flow, so that the pressure generated by reverse backflow gas can be uniformly distributed on the end face of the baffle plate, the structural integrity of the baffle plate is ensured, when the gas flow in the bypass ramjet engine channel forms forward flow and the channel needs to be opened, the baffle plate is very easy to break from the weak groove under the condition of lower pressure, the channel is completely opened, and the reliability of the separation action is ensured.

Drawings

FIG. 1 is a schematic view of a combination engine;

FIG. 2 is a schematic view of the airflow direction during a zero speed start of the combined engine;

FIG. 3 is a schematic view of a multi-flow path combination engine start protection configuration of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 at I;

FIG. 5 is an enlarged view of a portion of FIG. 3 at II;

FIG. 6 is a schematic view of the connection at I of FIG. 3 using an explosive bolt;

FIG. 7 is a schematic layout of a combination engine outlet.

The system comprises a turbine engine 1, a turbine engine 2, a bypass ramjet engine 3, a bypass ramjet engine 4, a tail pipe 5, a baffle plate 6, a weak groove 7 and an explosion bolt 8.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

As shown in fig. 3, the invention provides a multi-flow path combined engine start protection structure, the protection structure is a baffle plate arranged on the end surface of the outlet of a tail nozzle 5 of a bypass ramjet engine 3, the baffle plate 6 is connected with the tail nozzle 5 of the bypass ramjet engine 3 through a connecting mechanism and completely seals the outlet of the tail nozzle, after a turbine engine is started, the baffle plate 6 blocks reverse backflow gas, and the gas is prevented from flowing back into the turbine engine 1 through a bypass ramjet engine channel 4; after the bypass ramjet 3 is normally started, the air flow in the bypass ramjet channel 4 is formed into a forward flow.

The connecting mechanism can be a bolt or an explosion bolt 8, the baffle 6 falls off in a passive mode in a bolt connecting mode, as shown in the attached drawing 4, the bolt is not shown in a partial enlarged view, the baffle 6 and the tail nozzle 5 can be connected together through a connecting point in a bonding mode and other modes except the bolt, a weak groove 7 is machined in the connecting part of the baffle 6, the weak groove 7 in the baffle is positioned on the end face opposite to incoming flow, and the shape of the weak groove 7 is V-shaped; the rest parts of the baffle 6 are jointed with the end surface of the tail nozzle of the bypass ramjet engine without connection, as shown in figure 5.

The working principle that the baffle 6 falls off in a passive mode is as follows: when the engine is started, due to the pumping action of the turbine compressor, the force direction of the tail nozzle of the bypass ramjet engine 3 is from the outlet of the tail nozzle to the inlet of the engine, and at the moment, the outer edge of the baffle 6 is lapped on the outlet structure of the tail nozzle 5, and the tail nozzle 5 blocks the gas of the turbine engine from flowing backwards; when the incoming flow speed of the engine rises, the airflow in the ramjet engine is positive (from the inlet of the engine to the outlet of the engine), the force of the baffle plate points to the outlet direction of the tail jet pipe, the baffle plate 6 and the weak groove 7 of the tail jet pipe 5 are broken by force, the baffle plate 6 is separated from the tail jet pipe 5, and the ramjet engine establishes normal flow.

As shown in fig. 6, the baffle is connected with the exhaust nozzle of the bypass ramjet by using an explosion bolt 8, the explosion bolt is in an active falling mode, when a certain condition is met, an engine control system sends an instruction, the explosion bolt 8 is detonated, the baffle 6 is separated from the exhaust nozzle 5 of the bypass ramjet, and the combined ramjet establishes normal flow.

Fig. 7 shows the layout of the combined engine outlet, the central position is the turbine engine channel 2 of the turbine engine 1, the turbine engine 1 is taken as the center, the bypass ramjets 3 are sequentially distributed in the circumferential direction of the turbine engine 1, no baffle is arranged on the three bypass ramjets 3 on the left side, the bypass ramjet channel 4 is kept unobstructed, and baffles 6 are arranged on the four bypass ramjets 3 on the right side.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-flow path combined engine starting protection structure is characterized in that the protection structure is a baffle arranged on the end face of the outlet of a tail jet pipe of a bypass ramjet engine, the baffle is connected with the tail jet pipe of the bypass ramjet engine through a connecting mechanism and completely seals the outlet of the tail jet pipe, and after a turbine engine is started, the baffle blocks reverse backflow gas to prevent the gas from flowing back to the turbine engine through the bypass ramjet engine; after the bypass ramjet is normally started, the air flow in the channel of the bypass ramjet forms forward flow, and the connecting mechanism of the baffle falls off in an active or passive mode.

2. The multi-flow path combined engine start-up protection structure as claimed in claim 1, wherein the connection mechanism is a bolt or an explosive bolt, the connection mechanism falls off passively when the baffle is connected with the exhaust nozzle of the bypass ramjet by the bolt, a weak groove is processed on the connection portion of the baffle, and the rest of the baffle is attached to the end face of the exhaust nozzle of the bypass ramjet and is not connected; when the baffle plate is connected with the tail nozzle of the bypass ramjet through the explosion bolt, the baffle plate falls off in an active mode, the explosion bolt detonates under the control of an external instruction, and the baffle plate is separated from the tail nozzle of the bypass ramjet.

3. The multiple flow path combined engine start protection architecture of claim 2, wherein the weak point groove on the baffle is located on the end face opposite to the incoming flow, and the weak point groove is V-shaped.