JPH06294351A - Supersonic precooler for aircraft engine - Google Patents

Abstract

PURPOSE:To widen an operation area of an aircraft engine in using the engine in a supersonic field by improving cooling performance of intake air, increasing a compression ratio, downsizing equipment and reducing pressure loss accompanied with the cooling. CONSTITUTION:An intake main body 2 has an inner surface inclined in respect to an axis and a supersonic diffuser 3A thereinside. A precooler 4 is integrally assembled in the supersonic diffuser 3A, which precooler 4 is composed of a plurality of panel bodies 7 each having a coolant flow passage 6 being superposed vertically so as to form air passages 8A, 8B,...8N between adjacent panel bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supersonic precooler for an aircraft engine, which is arranged in front of an air breathing engine of an aircraft flying at supersonic speed to take in air.

[0002]

2. Description of the Related Art In this type of air breathing engine for an aircraft, the intake air can be compressed to a high pressure as much as possible in order to improve the launching capability of the aircraft, and the intake air can be downsized. It is required to lower the air temperature there below the upper temperature limit of the blade material of the axial flow compressor to be compressed.

As an air intake for an air breathing engine which meets such a demand, a structure disclosed in Japanese Patent Laid-Open No. 61-70158 is conventionally known. The air breathing engine disclosed in this publication has an air intake upstream of the axial compressor.
For example, a plate-tube type or fin-tube type air precooler that uses a cold heat source of liquid hydrogen or liquid hydrogen and liquid oxygen is attached, and air cooled to near the liquefaction temperature is axially flown by this air precooler. While introducing into the combustor after boosting the pressure by the compressor, the one configured to supply and burn liquid hydrogen or the like heated by heat exchange in the air precooler to the preburner, and downstream of the air precooler. Further, an air liquefier is provided, and a part of the air liquefied by the air liquefier is supplied to the preburner and burned.

The conventional air breathing
According to the engine, the intake air from the air intake is pre-cooled by the air precooler, or a part of it is liquefied to lower the temperature of the air flowing into the axial compressor, thereby reducing the specific volume of the air. Is reduced, the required power of the compressor can be reduced, and the compression ratio can be increased to increase the thrust.

[0005]

In the above-described conventional air precooler or the air breathing engine equipped with the air precooler and the air liquefier, the intake air flowing into the axial compressor is precooled. , Its specific volume can be reduced, the power required for the axial compressor can be reduced, and the compression ratio can be increased to increase the thrust force per unit air volume. Although it has the effect of suppressing the temperature rise of the machine,
As a pre-cooler of plate-tube type or fin-tube type is used, not only is it still insufficient in terms of heat exchange performance, that is, the cooling performance of intake air, When flying in a supersonic field, a supersonic diffuser that decelerates the supersonic flow below the speed of sound must be installed separately upstream of the diffuser. There was a lot of room for improvement as an air breathing engine.

The present invention has been made in view of the above circumstances, and when used in a supersonic field, the supersonic intake and the precooler are integrated to enable a significant downsizing of the equipment and to improve the cooling performance of the intake air. Air breathing by suppressing the pressure loss due to its cooling
An object of the present invention is to provide a supersonic precooler for an aircraft engine that can expand the operating range of the engine.

[0007]

In order to achieve the above-mentioned object, the present invention provides a supersonic precooler for an aircraft engine according to the present invention, which is an air-conditioner equipped with an axial compressor and a turbine.
A supersonic precooler for an air breathing engine, which is arranged in front of a freezing engine to take in air and guide the taken-in air to the above-mentioned axial flow compressor, and an intake which forms a supersonic diffuser inside. The main body and a precooler integrally incorporated in the supersonic diffuser inside the intake main body are provided, and the precooler is composed of a plurality of panel-shaped bodies in which refrigerant flow passages are closely formed, and vertically adjacent panel-shaped bodies. It is constructed by stacking vertically so that air passages are formed between the bodies.

[0008]

According to the above construction, the air taken into the supersonic diffuser formed by the intake body flows into the air passage between the vertically adjacent panel-like bodies in the precooler and is introduced into the rear axial flow compressor. To be done. Here, the air taken into each air passage is a supersonic flow,
The shock wave generated by this supersonic flow collides with the facing surface.
By repeating reflection and cooling the intake air by the pre-cooler, the boundary layer is stabilized and it becomes difficult for the boundary layer to separate from the surface of the panel-like body, and the heat transfer coefficient is improved by increasing the flow speed to increase the required heat transfer area. Since it can be made smaller, the heat exchanger can be made smaller.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view of an aircraft engine supersonic precooler according to the present invention, and FIG. 2 is a front view of the same.
In the figure, reference numeral 1 is an air breathing engine, and this air breathing engine 1 is a well-known device including an axial flow compressor, a tip turbine, a combustion chamber, and noise. The configuration is omitted.

Reference numeral 2 denotes an intake body which is arranged in front of the air breathing engine 1 to take in air and guide the taken-in air to an axial flow compressor of the air breathing engine 1. 2, as shown in FIG. 2, the four side plates 2A, 2B, 2C, 2
D is arranged in a rectangular shape, and the side plates 2
The inner surfaces of A, 2B, 2C and 2D are inclined with respect to the axis a passing through the center of the air breathing engine 1.
Moreover, the front end opening edge 2E extends from the front end edge of the upper plate 2A to the lower plate 2A.
The supersonic diffuser 3A and the subsonic diffuser 3B are formed inside by inclining toward the front end edge of B so as to be positioned obliquely rearward and downward.

Reference numeral 4 denotes a supersonic precooler integrally incorporated in the supersonic diffuser 3A inside the intake body 2.
5 is a subsonic diffuser 3 inside the intake body 2
It is a subsonic precooler integrated into B. As shown in FIGS. 3 and 4, the supersonic precooler 4 uses LH2 which is a fuel in the air breathing engine 1 as a refrigerant, and the LH2 refrigerant flow path 6 is in a direction orthogonal to the axis a. A plurality of panel-shaped bodies 7 formed in a zigzag pattern closely spaced with each other are provided between the panel-shaped bodies 7, 7 whose front end edges are aligned with the front end opening edges 2E of the intake body 2 and which are vertically adjacent to each other. Air passage 8
.. 8N are formed by stacking vertically. The LH2 refrigerant flow paths 6 of the plurality of panel-shaped bodies 7 constituting the supersonic precooler 4 are sequentially connected to each other through a communication pipe 9 which is bent in a substantially U shape.

The subsonic precooler 5 comprises a plurality of LH2 refrigerant pipes 10 which are arranged in the subsonic diffuser 3B vertically and longitudinally at appropriate intervals and communicate with each other, and these LH2 refrigerant pipes 10 are connected to each other. For example, as shown in FIG. 6, the cross-section has a low aerodynamic pressure loss with respect to the flow direction of the intake air.

Next, the operation of the supersonic precooler for an aircraft engine having the above structure will be described. Along with the supersonic flight of the aircraft, the air taken into the supersonic diffuser 3A inside the intake body 2 flows into the upper and lower air passages 8A, 8B, ... 8N of the supersonic precooler 4, respectively, and these air passages are respectively introduced. 8A, 8B, ... Flows backward in 8N. Here, the shock wave SW generated at the front edge of the panel-shaped body 7 by the supersonic flow of intake air is
When propagating backward in A, 8B, ..., 8N, as shown in FIG. 5, it collides against the facing surfaces of the vertically adjacent panel-shaped bodies 7, 7 and is reflected to be transmitted backward. Therefore, the air passing between the panel-like bodies 7 is absorbed by the LH2 refrigerant and is cooled, and the specific volume is reduced. At the same time, shock wave SW
Is attenuated.

Next, the air whose temperature has been lowered and which has reached the subsonic region is further cooled by the heat exchange with the LH2 refrigerant flowing in the refrigerant pipe 10 of the subsonic precooler 5, and the specific volume is reduced, It will be installed in the axial compressor of the air breathing engine 1.

As described above, the required power of the axial flow compressor can be reduced by reducing the specific volume by cooling the intake air and the pressure loss due to the cooling, and the axial flow can be reduced by lowering the air temperature. The cost of the material can be reduced without imposing excessive demands on the heat resistance of the blade material of the compressor.

In the above embodiment, the intake body 2
The supersonic precooler 4 and the subsonic precooler 5 having different configurations are shown in the figure, but the configuration of the subsonic precooler 5 is the same as that of the supersonic precooler 4.
The panel-shaped body 7 may have a laminated structure. Further, as the panel-shaped body of the present invention, in the above-described embodiment, the LH2 refrigerant flow channel 6 is shown as being formed in the panel-shaped body 7 made of a plate body in a zigzag shape with a close spacing, but only the LH2 refrigerant flow channel 6 is shown. May be formed in close contact with each other to form a zigzag shape.

[0017]

As described above, according to the present invention, the precooler having the laminated structure of the panel-shaped body is integrally incorporated into the supersonic diffuser in the intake body.
The heat transfer area can be increased by increasing the heat exchange area per unit volume and speeding up the flow, which facilitates miniaturization as well as by the shock waves generated between multiple panel-like bodies. Improves the cooling performance of the intake air by increasing the heat transfer coefficient between the intake air and the refrigerant flowing in the refrigerant channel formed in the panel-like body, and increases the reduction rate of the specific volume of the intake air to increase the flow rate. The static pressure can be significantly increased. Further, the pressure can be recovered by cooling. Therefore, the required power of the compressor is reduced, and when a compressor with the same capacity as the conventional one is used, a decrease in the compressor inlet temperature and an increase in the turbine outlet temperature can be achieved at the same time. The air breathing engine operating range can be expanded. Further, since the compressor inlet temperature can be lowered by cooling, the cost of the compressor blade material can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic side view of a supersonic precooler for an aircraft engine according to the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a partially cutaway perspective view of an air intake with a supersonic precooler.

FIG. 4 is a vertical sectional side view of FIG.

FIG. 5 is a diagram for explaining a cooling action of the supersonic precooler.

FIG. 6 is a sectional view of a refrigerant pipe of a subsonic precooler.

[Explanation of symbols] 1 Air breathing engine 2 Intake body 3A Supersonic diffuser 4 Supersonic precooler 6 LH2 Refrigerant flow path 7 Panel-like body 8A, 8B, ... 8N Ventilation path SW Shock wave

Front page continuation (72) Inventor Shogo Hayashi 2-8-1, Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries Ltd. Seishin Factory (72) Inventor Akira Fujimoto 1 Kawasaki-cho, Kakamigahara-shi, Gifu Kawasaki Heavy Industries Ltd. Company Gifu factory (72) Inventor Jun Inai 1-1 Kawasaki-cho, Akashi-shi, Hyogo Prefecture Kawasaki Heavy Industries Ltd. Akashi factory (72) Inventor Kei Kawashima 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries Akashi Co., Ltd. in the factory

Claims (1)

[Claims] 1. A supersonic precooler for an aircraft engine, which is arranged in front of an air breathing engine equipped with an axial compressor and a turbine to take in air and guide the taken air to the axial compressor. And
It has an intake body that forms a supersonic diffuser inside, and a precooler that is integrated into the supersonic diffuser inside the intake body.The precooler is composed of a plurality of panel-shaped bodies in which refrigerant flow passages are closely formed. A supersonic precooler for an aircraft engine, wherein the supersonic precooler is vertically stacked so that air passages are formed between vertically adjacent panel-shaped bodies.