阅读说明：本技术 一种降低双脉冲固体发动机隔层应变的燃烧室 (Combustion chamber for reducing interlayer strain of double-pulse solid engine ) 是由 李青频 郭运强 张翔宇 利凤祥 甘晓松 黄薇薇 张飞 薛太旭 赵康 于 2019-08-20 设计创作，主要内容包括：本发明公开了一种降低双脉冲固体发动机隔层应变的燃烧室,包括隔层、绝热层、药柱和壳体；药柱设置在壳体内,药柱与壳体之间设置绝热层,隔层将药柱沿轴向分隔成两段；前端药柱与后端药柱相对的端面上设置环形槽,该隔层与前端药柱端面形状匹配。本发明能够降低径向隔层环向应变。(The invention discloses a combustion chamber for reducing interlayer strain of a double-pulse solid engine, which comprises an interlayer, a heat insulation layer, a grain and a shell; the explosive column is arranged in the shell, a heat insulation layer is arranged between the explosive column and the shell, and the interlayer divides the explosive column into two sections along the axial direction; the end face of the front end grain opposite to the rear end grain is provided with an annular groove, and the shape of the interlayer is matched with that of the end face of the front end grain. The invention can reduce the circumferential strain of the radial interlayer.)

1. A combustion chamber for reducing interlayer strain of a double-pulse solid engine is characterized by comprising an interlayer, a heat insulation layer, a grain and a shell;

The explosive column is arranged in the shell, a heat insulation layer is arranged between the explosive column and the shell, and the interlayer divides the explosive column into two sections along the axial direction; the end face of the front end grain opposite to the rear end grain is provided with an annular groove, and the shape of the interlayer is matched with that of the end face of the front end grain.

2. the dual pulse solid engine barrier strain reducing combustor according to claim 1 wherein said annular groove is a body of revolution formed by a plane curve rotating 360 ° about the engine central axis, said plane curve being formed by two parallel line segments of equal length parallel to the central axis and an arc connecting the two parallel line segments.

3. The double pulse solid engine barrier strain reducing combustion chamber of claim 2 wherein said arc is a semi-circle.

4. The dual pulse solid engine barrier strain reducing combustor according to claim 3 wherein said parallel line segment length is L, the semi-circular radius is R, the radial distance between the annular groove and the outer circumferential surface of the front end charge is H, and is determined L, R, H using an optimization algorithm with the goal of minimizing the hoop strain of the radial barrier at the lowest operating temperature of the engine, subject to the constraint that the thrust-time curve of the engine meets the required thrust-time curve envelope, said lowest operating temperature being set by the missile ensemble.

Technical Field

The invention relates to the technical field of double-pulse solid engines, in particular to a combustion chamber for reducing interlayer strain of a double-pulse solid engine.

Background

A new generation of tactical missile weapons, particularly air defense anti-missile missiles, require a solid engine to have more flexible energy management capability. Due to the advantages of energy management of the double-pulse solid engine, the missile has a longer range, a higher final speed and higher maneuverability. By designing I/II pulse working time and pulse interval time, the energy of the whole working process of the engine can be effectively distributed, and the operational efficiency of the missile is improved.

The double-pulse solid engine is divided into two types of compartment type and interlayer type. The compartment type double-pulse solid engine adopts a rigid hard isolation mode, the engine is axially divided into two combustion chambers by the compartment, and the compartment is used as an independent bearing structure of the engine to bear the working pressure of the pulse combustion chamber I. The interlayer type double-pulse solid engine adopts a flexible soft isolation mode, the explosive column in the engine combustion chamber is divided into two parts by the interlayer, the interlayer is not used as an independent bearing structure of the engine, the working pressure of the I pulse combustion chamber is born by the II pulse explosive column 7 and the heat insulation shell, and meanwhile, the heat insulation and sealing effects are also achieved.

Compared with a compartment type double-pulse engine, the compartment type double-pulse engine has the advantages of light passive mass and high mass ratio. However, the stratified double-pulse engine has the disadvantages that the lower limit of the use temperature is generally higher than that of the cabin type double-pulse engine, and the safety coefficient of the stratified is low at low temperature. For a interlayer type double-pulse solid engine, along with the reduction of the using temperature of the engine, the strain of an interlayer is increased, the fracture strain of an interlayer material is reduced, when the strain of the interlayer exceeds the fracture strain of the interlayer material, the interlayer is damaged, so that the interlayer is failed to cause the penetration between I/II pulse grains, the I/II pulse grains are simultaneously combusted, the pressure of a combustion chamber is rapidly increased, and when the pressure of the combustion chamber exceeds the explosion pressure of an engine shell 10, the engine explodes.

For a stratified double pulse engine, hoop strain of the radial barrier 4 exceeding the fracture strain of the radial barrier 4 material is the most common cause of barrier failure. The current interlayer type double-pulse solid engine always ensures that the interlayer normally works at low temperature by a method of improving the fracture strain of an interlayer material at low temperature (-40 ℃). The main functions of the interlayer are ablation resistance and heat insulation, so the interlayer material is usually selected as a heat insulation material, the fracture strain of the heat insulation material at low temperature (-40 ℃) is smaller, and the improvement of the fracture strain of the heat insulation material greatly increases the development cost and the development period.

the structure of a conventional interlayer type double-pulse solid engine is shown in figure 1 and comprises a pulse igniter 1I, a top cover 2, a pulse igniter 3 II, a radial interlayer 4, a heat insulating layer 5, a manual debonding layer 6, a pulse explosive column II 7, an axial interlayer 8, a pulse explosive column I9, a shell 10 and a spray pipe 11. In the 9 course of working of I pulse powder columns of engine, the interlayer need bear high temperature and high pressure environment, and high pressure environment can make radial interlayer 4 produce great hoop strain, and the hoop strain of radial interlayer 4 can be confirmed by formula (1), in the formula: ε is the strain at any point on the radial spacer 4, u is the radial displacement at that point, and r is the radius at that point. Conventional combustors utilize an artificial debond layer 6 to relieve stress.

The radial displacement of the radial spacers 4 is made up of two parts: the first part is that the radial interlayer 4 and the II pulse grain 7 shrink and deform along with the reduction of the service temperature of the engine, and a gap is generated between the radial interlayer 4 and a middle hole of the II pulse grain 7, when the I pulse grain 9 of the engine is just ignited by the I pulse igniter 1, the radial interlayer 4 deforms and clings to the II pulse grain 7 under the action of very small pressure (usually 0.1-0.2 MPa), the radial displacement of the radial interlayer 4 is U, and the U increases along with the reduction of the working temperature of the engine; the second part is that the interlayer and the explosive column continue to deform along with the increase of the pressure intensity until reaching a balance state (the pulse working pressure intensity of the engine I reaches the maximum value, usually 10-20 MPa), and the radial displacement generated when the radial interlayer 4 reaches the balance state from the pulse explosive column 7 close to the radial interlayer II is U ', and the U' is reduced along with the reduction of the working temperature of the engine. The total radial displacement of the radial spacer 4 is U + U ', since the increase of U is much greater than the decrease of U ', U + U ' increases with the decrease of the engine operating temperature, and when the maximum hoop strain of the radial spacer 4 exceeds the fracture strain of the material of the radial spacer 4 at that temperature, the radial spacer 4 will break.

Disclosure of Invention

in view of the above, the invention provides a combustion chamber for reducing interlayer strain of a double-pulse solid engine, which can reduce circumferential strain of a radial interlayer.

the specific embodiment of the invention is as follows:

A combustion chamber for reducing interlayer strain of a double-pulse solid engine comprises an interlayer, a heat insulation layer, a grain and a shell;

The explosive column is arranged in the shell, a heat insulation layer is arranged between the explosive column and the shell, and the interlayer divides the explosive column into two sections along the axial direction; the end face of the front end grain opposite to the rear end grain is provided with an annular groove, and the shape of the interlayer is matched with that of the end face of the front end grain.

Furthermore, the annular groove is a rotating body formed by rotating a plane curve by 360 degrees around the central axis of the engine, and the plane curve is formed by two parallel line segments with equal length parallel to the central axis and an arc line connecting the two parallel line segments.

Further, the arc line is a semicircle.

Further, the length of the parallel line segment is L, the semi-circle radius is R, the radial distance between the annular groove and the outer circle surface of the front end grain is H, L, R, H is determined by utilizing an optimization algorithm, the optimization target is to enable the circumferential strain of the radial interlayer to be minimum at the lowest working temperature of the engine, the constraint condition is that the thrust-time curve of the engine meets the required thrust-time curve enveloping range, and the lowest working temperature is set by the missile overall.

Has the advantages that:

1. According to the invention, the combustion chamber is free from a manual debonding layer, the annular groove is added to the II pulse grain, the stress is released by the annular groove, the strain borne by the radial interlayer is transferred to the axial interlayer, and the increase of the displacement U of the first part of the radial interlayer along with the temperature reduction can be effectively reduced, so that the circumferential strain of the radial interlayer is reduced, the lower limit of the service temperature of the engine is widened, and the low-temperature working safety coefficient of the engine is improved.

2. the shape of the annular groove can avoid stress concentration, and because the change to the surface is as small as possible, the combination of the semicircle and the parallel line segment is adopted in the invention to ensure that the circumference of the annular groove is the minimum.

Drawings

FIG. 1 is a schematic diagram of a conventional stratified double-pulse solid engine;

FIG. 2 is a schematic diagram of a double pulse solid engine according to the present invention;

FIG. 3 is a partial schematic view of an annular groove of the present invention;

FIG. 4 is a partial schematic view of an axial plenum annular body of the present invention;

Wherein, 1-I pulse igniter, 2-top cover, 3-II pulse igniter, 4-radial interlayer, 5-heat insulating layer, 6-artificial debonding layer, 7-II pulse grain, 8-axial interlayer, 9-I pulse grain, 10-shell and 11-spray pipe.

Detailed Description

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

The present embodiment provides a combustion chamber for reducing barrier strain in a double pulse solid engine, as shown in fig. 2, comprising a radial barrier 4, a thermal insulation layer 5, a charge, an axial barrier 8 and a housing 10, wherein the manual release layer 6 is eliminated compared to a conventional barrier double pulse solid engine combustion chamber structure.

the explosive column is arranged in a shell 10, a heat insulation layer 5 is arranged between the explosive column and the shell 10, and the radial interlayer 4 and the axial interlayer 8 divide the explosive column into two sections along the axial direction, namely an I pulse explosive column 9 and an II pulse explosive column 7. 10 one end of casing is sealed by top cap 2, and casing 10 other end fixed connection spray tube 11, radial interlayer 4 and top cap 2 integrated into one piece, and I pulse igniter 1, II pulse igniter 3 all fix on top cap 2, are used for igniting I pulse powder column 9, II pulse powder column 7 respectively, constitute the engine from this. The II pulse grain 7 is positioned at the front end and is far away from the spray pipe 11, and the I pulse grain 9 is positioned at the rear end. The radial interlayer 4 is wrapped on the inner circumferential surface of the II pulse grain 7, the axial interlayer 8 is wrapped on the end surface of the II pulse grain 7 opposite to the I pulse grain 9, meanwhile, the radial interlayer 4 is lapped on the inner side of the axial interlayer 8, and the lapping position is positioned at the corner of the inner circumferential surface of the II pulse grain 7 and the end surface, and the axis of the solid engine is positioned inside; the end face of the pulse grain II 7 opposite to the pulse grain I9 is provided with an annular groove, the shape of the axial interlayer 8 is matched with that of the end face of the pulse grain II 7, and an annular body matched with the annular groove is added. The annular groove and the annular body are rotating bodies formed by rotating a plane curve for 360 degrees around the central axis of the engine, the plane curve is composed of two equal-length parallel line segments parallel to the central axis and a semicircle connecting the two parallel line segments, as shown in fig. 3, the line segment is L, the semicircle radius is R, the radial distance between the annular groove and the outer circular surface of the II pulse grain 7 is H, and the radial distance between the annular body and the outer circular surface of the axial interlayer 8 is H, as shown in fig. 4.

The specific design implementation process is as follows:

Step one, I/II pulse drug type design is completed according to the requirement of the overall thrust-time curve of the missile, and the II pulse drug column 7 does not contain an artificial debonding layer 6 and an annular groove.

And step two, calculating the internal flow field of the engine when the I pulse grain 9 works by using commercial finite element software, and determining the materials and the thicknesses of the radial interlayer 4 and the axial interlayer 8.

And step three, determining design parameters L, R and H by using an optimization algorithm. The optimization target is to minimize the annular strain of the radial interlayer 4 at the lowest working temperature of the engine, the lowest working temperature is set by the total missile and is generally-40 ℃, and the thrust-time curve of the engine is influenced because the II pulse pressure-time curve is influenced after the II pulse explosive column 7 opens the annular groove, so that the constraint condition is that the thrust-time curve meets the thrust-time curve enveloping range of the total missile requirement.

And step four, calculating the circumferential strain of the radial interlayer 4 of the engine combustion chamber structure determined in the step three at the lowest working temperature of the engine by using commercial software, and comparing the circumferential strain with the fracture strain of the radial interlayer 4 material determined in the step two at the lowest working temperature of the engine to obtain the low-temperature safety coefficient of the radial interlayer 4, thereby proving that the low-temperature working reliability of the engine is improved.

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.