CN103742296B - A kind of gaseous film control jet pipe - Google Patents

Abstract

The present invention relates to a kind of gaseous film control jet pipe, including jet pipe leading portion and jet pipe extension, jet pipe leading portion is fixedly connected with jet pipe extension by ring flange, also include aerofluxuss collector and inlet bend, one end of aerofluxuss collector is fixed on the outer wall of jet pipe leading portion, the other end of aerofluxuss collector is fixed on ring flange, the outer wall of aerofluxuss collector, ring flange and jet pipe leading portion constitutes cryogenic gas chamber, one end of inlet bend is fixed on aerofluxuss collector and is connected with cryogenic gas chamber, and the other end of inlet bend is connected with cryogenic gas source；Multiple exhaust nozzles are evenly distributed on ring flange, with the center of ring flange as the center of circle, the radius of a circle residing for exhaust nozzle is less than the radius of a circle residing for junction of jet pipe extension and ring flange, and cryogenic gas chamber is connected by exhaust nozzle with jet pipe extension.The present invention solves the relatively costly technical problem of the mode that jet pipe extension is cooled down, and design structure of the present invention is simple, low cost, and cooling effect is notable.

Description

A kind of gaseous film control jet pipe

Technical field

The present invention relates to cryogenic gas is introduced thrust chamber spray by a kind of motor power room chiller, particularly one kind Then gaseous film control is introduced the device of jet pipe extension by pipe, is also a kind of method improving engine/motor specific impulse.

Background technology

One feature of upper stage rocket engine is exactly that specific impulse has high demands, and the raising of motor power room specific impulse is mainly passed through to carry High thrust chamber efficiency of combustion and the method increasing exit area ratio, but after the raising to a certain extent of thrust chamber efficiency of combustion more very Difficult raising, then passing through increase exit area ratio becomes an effective way improving engine/motor specific impulse.Upper stage rocket engine by In ambient pressure environment very little, almost vacuum, exit area ratio can be almost suitable in the case of allowing between engine air Unlimited increase, but the increase with exit area ratio, because propellant flow rate is limited, for high chamber pressure thrust chamber, adopt It is impossible that re-generatively cooled mode cools down whole jet pipe；Using extendible nozzle, technical difficulty, lead time and cost are to think And know；Increase the radiation type of cooling of coating using single wall thin slice, development cost also will increase a lot.Therefore, adopt one Planting the inexpensive method that jet pipe extension effectively can be cooled down just becomes one during upper stage rocket engine thrust chamber is developed Important research topic.

Content of the invention

The technical problem relatively costly in order to solve the existing mode that jet pipe extension is cooled down, the present invention provides A kind of gaseous film control jet pipe, design structure is simple, low cost, and cooling effect is notable；Also engine/motor specific impulse can be improved as a kind of Method.

The technical solution of the present invention is：

A kind of gaseous film control jet pipe, including jet pipe leading portion 2 and jet pipe extension 6, described jet pipe leading portion 2 passes through flange Disk 5 is fixedly connected with jet pipe extension 6, also includes aerofluxuss collector 1 and inlet bend 3, one end of described aerofluxuss collector 1 It is fixed on the outer wall of jet pipe leading portion 2, the other end of described aerofluxuss collector 1 is fixed on ring flange 5, described aerofluxuss set The outer wall of device 1, ring flange 5 and jet pipe leading portion 2 constitutes cryogenic gas chamber,

One end of described inlet bend 3 is fixed on aerofluxuss collector 1 and is connected with cryogenic gas chamber, described inlet bend 3 other end is connected with cryogenic gas source；

It has been evenly distributed multiple exhaust nozzles on described ring flange 5, with the center of ring flange as the center of circle, described aerofluxuss spray Radius of a circle residing for mouth is less than the radius of a circle residing for junction of jet pipe extension 6 and ring flange 5, and described exhaust nozzle will Cryogenic gas chamber is connected with jet pipe extension.

Also include cone cylinder 4, described cone cylinder 4 is fixed on ring flange 5, described cone cylinder 4 is located in jet pipe extension, described cone Radius of a circle residing for cylinder 4 is less than the radius of a circle residing for exhaust nozzle.

The inner mold face of above-mentioned cone cylinder 4 arrival end is consistent with the inner mold face of the jet pipe leading portion port of export.

The other end of above-mentioned inlet bend 3 is connected with turbine exhaust pipe.

Above-mentioned aerofluxuss collector 1 is variable cross-section airflow design.

Above-mentioned exhaust nozzle is velocity of sound exhaust nozzle.

The diameter of above-mentioned jet pipe extension 6 is gradually increased along the flow direction of cryogenic gas.

The section of above-mentioned exhaust nozzle is cylindrical or Long Circle.

Advantage for present invention：

1st, the variable cross-section airflow design of the aerofluxuss collector of the present invention is it is ensured that press at each exhaust nozzle inlet/outlet Power, speed circumference are all even stable.

2nd, exhaust nozzle is designed to velocity of sound exhaust nozzle by the present invention, it is to avoid outlet pressure disturbance produces to turbine back-pressure Disturbance.

3rd, the jet pipe extension of the present invention adopts the design of not isometrical distance of increment, by existing vertically in jet pipe extension Radially increase the space of different distance it is ensured that the main combustion gas of thrust chamber is equal at same section with turbine exhaust.

4th, the present invention arranges cone cylinder at exhaust nozzle downstream, makes turbine exhaust form uniformly annular air film patch jet pipe and extends Section wall flowing, solves the disturbance to main combustion gas for the turbine exhaust.

Brief description

Fig. 1 is the structural representation of gaseous film control jet pipe of the present invention；

Fig. 2 is the partial sectional view of Fig. 1；

The jet pipe extension wall temperature curve chart that Fig. 3 records in heat run for the present invention；

Fig. 4 is present configuration and the wall temperature comparison diagram not taking present configuration jet pipe extension；

Fig. 5 is exhaust nozzle structure diagram of the present invention, and wherein Fig. 5-1 is cylindrical schematic diagram；Fig. 5-2 illustrates for Long Circle Figure；

Fig. 6 is aerofluxuss collector structural representation of the present invention；

Fig. 7 is that the jet pipe after cryogenic gas of the present invention introduces extends segment type face schematic diagram；

Fig. 8 is cone cylinder structural representation of the present invention；

Wherein reference is：1- aerofluxuss collector, 2- jet pipe leading portion, 3- inlet bend, 4- cone cylinder, 5- ring flange, 6- jet pipe extension, 7- exhaust nozzle.

Specific embodiment

As shown in Figure 1 and Figure 2, the structure of the present invention is by jet pipe leading portion 2, jet pipe extension 6, inlet bend 3, aerofluxuss collection Clutch 1, ring flange 5, exhaust nozzle 7, cone cylinder 4 etc. zero parts form.It is designed to sonic nozzle along exhaust nozzle 7, it is to avoid its Pressure disturbance afterwards produces impact to upstream back pressure.The effect of cone cylinder 4 is to force turbine exhaust to form uniformly annular air film patch spray The wall flowing of pipe extension, and make cryogenic gas form circumferential weld outlet pressure and cone cylinder port of export turbine in cone cylinder with ring flange Aerofluxuss are equal with pressure at the fusion of main combustion gas；The inner mold face of cone cylinder arrival end is consistent with jet pipe leading portion port of export inner mold face, Cone cylinder port of export internal diameter is equal to the diameter at turbine exhaust and the fusion of main combustion gas, for simplifying structure, is designed to cone cylinder.Main combustion gas Enter jet pipe extension 6 along jet pipe leading portion 2, merge in jet pipe extension 6 with turbine exhaust.

Ring flange is the connector between jet pipe leading portion and jet pipe extension, welding jet pipe leading portion on ring flange Inside and outside wall, the parts such as the spiral case of processing exhaust nozzle and welding aerofluxuss collector 1 and cone cylinder on ring flange simultaneously.Aerofluxuss collection The effect of clutch is so that each exhaust nozzle pressure at inlet, speed is kept the uniform, outer wall by jet pipe leading portion and be welded in thereon The spiral case of aerofluxuss collector 1 formed.Aerofluxuss are introduced aerofluxuss collector with suitable stream by inlet bend, inlet bend with Cryogenic gas pipe can be using welding and flange connection.Turbine exhaust pipe selected by general cryogenic gas pipe.

The operation principle of the present invention is that by inlet bend, turbine exhaust in turbine exhaust pipe is introduced aerofluxuss collector, then Spray into along the flowing of jet pipe extension wall through exhaust nozzle, form the air film being close to jet pipe wall, make turbine exhaust pressure and push away The main gaseous-pressure in power room is equal at same section, to main combustion gas undisturbed；The main fuel gas temperature in turbine exhaust relative force room is very Low, jet pipe extension is played with cooling protection effect；Simultaneously with main combustion gas aftercombustion, expansion, last discharge at a high speed, obtain one Gain in partial properties.

The invention has the beneficial effects as follows：Notable to thrust chamber jet pipe extension cooling effect, also have one to engine/motor specific impulse Fixed raising, design structure is simple, and Financial cost is low.Electromotor thrust chamber jet pipe extension in altitude simulation test run is uniformly warm Degree measuring point Twc1, Twc2.Wherein Twg is the jet pipe extension gas wall temperature curve being not introduced into turbine exhaust, and T ＇ wg is to introduce turbine Jet pipe extension gas wall temperature curve after aerofluxuss.

Can be seen that from Fig. 3 and Fig. 4：

（1）763 DEG C of the maximum temperature that test run measures（Away from entrance 200mm about）, jet pipe extension with Theoretical Calculation About 783 DEG C of peak temperature compares difference less, basically identical.

（2）Introduce turbine exhaust gaseous film control jet pipe extension effect substantially, jet pipe extension gas wall temperature is little from holding greatly End is decreased obviously 100-500 DEG C.

The present invention, in order to realize not producing disturbance to upstream back pressure after turbine exhaust introducing jet pipe, turbine exhaust is entered spray The nozzle of pipe is designed to velocity of sound exhaust nozzle, it is to avoid turbine exhaust outlet pressure pulsations produce disturbance to upstream back pressure.

The design of exhaust nozzle：

By formula（1）Calculate import bend pipe area A_if1：

By formula（2）Calculate exhaust entrance Mach number Ma₁：

By formula（3）Calculate exhaust entrance stagnation temperature T_te*：

By formula（4）Calculate exhaust entrance stagnation pressure p_te*.

By formula（5）Calculate exhaust nozzle pressure ratio r_ph.

ξ_pTo be selected according to the planform of inlet bend and aerofluxuss collector and size or to pass through model blowing test To measure, typically to choose 0.7～0.85.

By formula（6）Calculate exhaust nozzle critical pressure ratio r_phcr.

If r_ph≤r_phcrExhaust nozzle just may be designed to the velocity of sound or supersonic nozzle.

By formula（7）Calculate the throat gross area A of the velocity of sound or supersonic nozzle_th.

Typically take Cdh=0.9～1.0

By formula（8）Calculate divergence ratio ε of exhaust nozzle_h.

By formula（9）Calculate exhaust nozzle outlet gross area A_eh.

A_eh=ε_hA_th（9）

By formula（10）Calculate the throat internal diameter d of exhaust nozzle_th.

Typically take s₁=（3～5）x10^-3m

By formula（11）Calculate quantity n of exhaust nozzle_h.

By formula（12）Calculate minimum range s between throat's wall of cylindrical air exhaust nozzle₁.

By formula（13）Calculate exhaust nozzle distance s₂.

If exhaust nozzle designs long circle hole, its length is equal to the twice of width, and its nozzle quantity is than cylindrical The few half of nozzle quantity, the distance between throat's wall of adjacent nozzle can double, and cylindrical and oblong nozzle sketch is shown in Fig. 5.

The present invention introduces jet pipe tailing edge jet pipe circumferential pressure, all even steady flow of speed to realize turbine exhaust, leads to Cross bend pipe and cryogenic gas is introduced variable cross-section fairshaped aerofluxuss collector so that turbine exhaust introduces jet pipe leading-edge thrust room week Uniformly equal to pressure distribution.

The design of aerofluxuss collector：

It is made up of with the aerofluxuss collector housing being welded in thereon the outside wall surface of thrust chamber jet pipe leading portion.

Aerofluxuss collector shape of cross section is substantially semi-circular design, and its cross-sectional area is change, the entering of aerofluxuss At mouthful（As 0 ° of position）Cross-sectional area is maximum, and its radius is maximum, equal to the inside radius of inlet bend, that is,：r_max=d_if1/2.

The cross section just locating to differ at 180 ° with exhaust entrance is the minimum cross-section of aerofluxuss collector, and its radius is minimum, I.e. r_min=b₂.

From 0 ° to 180 °, its cross-sectional area is equably reduced to minimum area from maximum area to aerofluxuss collector.Arbitrarily The cross sectional radius r of angular position_βBy formula（14）Calculate.

The two halves of aerofluxuss collector（0 °～180 ° and 0 °～-180 °）It is full symmetric.

For ease of the assemble welding of aerofluxuss collector housing, aerofluxuss collector shape of cross section, locally vary slightly, not complete It is semicircular entirely.

In order to ensure the intensity at inlet bend position, inlet bend adopts solid forging structure, and aerofluxuss collector housing is tied Fig. 6 is shown in by structure sketch.

The present invention is equal everywhere in same sectional pressure with turbine exhaust in order to realize main combustion gas, because turbine exhaust is in spray Burn away in pipe, expand, the jet pipe after turbine exhaust leading-in end is axially outwards increased radially increasing Unequal distance along jet pipe Certain distance is it is ensured that main combustion gas is isobaric everywhere in same section with thrust chamber after cryogenic gas introducing jet pipe.

Aerofluxuss introduce area jet nozzle inside radius increment △ rs and press formula（15）Calculate：

Other area jet nozzle inside radius increment △ rx press formula（16）Calculate：

Jet pipe after cryogenic gas introduces extends segment type face schematic diagram, sees Fig. 7.

The present invention does not produce disturbance in order to realize turbine exhaust to main combustion gas, enters setting cone at jet pipe in turbine exhaust Cylinder, makes turbine exhaust form uniformly annular air film patch jet pipe extension wall flowing.Cone cylinder structure diagram is shown in Fig. 8.

Claims (7)

1. a kind of gaseous film control jet pipe, including jet pipe leading portion (2) and jet pipe extension (6), described jet pipe leading portion (2) is passed through Ring flange (5) be fixedly connected with jet pipe extension (6) it is characterised in that：Also include aerofluxuss collector (1) and inlet bend (3), one end of described aerofluxuss collector (1) is fixed on the outer wall of jet pipe leading portion (2), described aerofluxuss collector (1) another One end is fixed on ring flange (5), and the outer wall of described aerofluxuss collector (1), ring flange (5) and jet pipe leading portion (2) is constituted Cryogenic gas chamber,

One end of described inlet bend (3) is fixed on aerofluxuss collector (1) above and is connected with cryogenic gas chamber, described inlet bend (3) the other end is connected with cryogenic gas source；

It has been evenly distributed multiple exhaust nozzles on described ring flange (5), with the center of ring flange as the center of circle, described exhaust nozzle Residing radius of a circle is less than the radius of a circle residing for junction of jet pipe extension (6) and ring flange (5), described exhaust nozzle Cryogenic gas chamber is connected with jet pipe extension, described aerofluxuss collector (1) is variable cross-section airflow design；

The design of exhaust nozzle：

Calculate import bend pipe area A by formula (1)_if1：

$A_{if1}=\frac{\mathrm{\π}}{4}{d}_{if1}^2---\left(1\right)$

Calculate exhaust entrance Mach number Ma by formula (2)₁：

${\mathrm{Ma}}_1=\frac{q_{mte}}{A_{if1}{p}_{te}}\sqrt{\frac{{\mathrm{RT}}_{te}}{k}}---\left(2\right)$

Calculate exhaust entrance stagnation temperature T by formula (3)_te*：

$T_{te}^{*}=(1+\frac{1+k}{2}{\mathrm{Ma}}_1^2)T_{te}---\left(3\right)$

Calculate exhaust entrance stagnation pressure p by formula (4)_te*：

$p_{te}^{*}=p_{te}{(1+\frac{k-1}{2}{\mathrm{Ma}}_1^2)}^{\frac{k}{k-1}}---\left(4\right)$

Calculate exhaust nozzle pressure ratio r by formula (5)_ph：

$r_{ph}=\frac{p_e}{{\mathrm{\ξ}}_p{p}_{te}^{*}}---\left(5\right)$

ξ_pTo be selected according to the planform of inlet bend and aerofluxuss collector and size or to be surveyed by model blowing test Fixed, choose 0.7～0.85；

Calculate exhaust nozzle critical pressure ratio r by formula (6)_phc：

$r_{phcr}={\left(\frac{2}{k+1}\right)}^{\frac{k}{k-1}}---\left(6\right)$

If r_ph≤r_phcrExhaust nozzle is designed to the velocity of sound or supersonic nozzle；

Calculate the throat gross area A of the velocity of sound or supersonic nozzle by formula (7)_th：

$A_{th}=\frac{q_{mte}\sqrt{{\mathrm{RT}}_{te}^{*}}}{{\mathrm{\ξ}}_p{C}_{dh}{p}_{te}^{*}\sqrt{k{\left(\frac{k}{k+1}\right)}^{\frac{k+1}{k-1}}}}---\left(7\right)$

Take C_dh=0.9～1.0

Calculate divergence ratio ε of exhaust nozzle by formula (8)_h：

${\mathrm{\ϵ}}_h=\frac{{\left(\frac{k-1}{2}\right)}^{\frac{1}{2}}{\left(\frac{2}{k+1}\right)}^{\frac{k+1}{2(k-1)}}}{{(1-{r_{ph}}^{\frac{k-1}{k}})}^{\frac{1}{2}}{r_{ph}}^{\frac{1}{k}}}---\left(8\right)$

Calculate exhaust nozzle outlet gross area A by formula (9)_eh：

A_eh=ε_hA_th(9)

Calculate the throat internal diameter d of exhaust nozzle by formula (10)_th：

$d_{th}=\frac{2A_{th}+2\sqrt{A_{th}^2+{\mathrm{\π}}^2{s}_1{d}_s{A}_{th}}}{{\mathrm{\π}}^2{d}_s}---\left(10\right)$

Take s₁=(3～5) x10^-3m

Calculate quantity n of exhaust nozzle by formula (11)_h：

$n_h=\frac{4A_{th}}{{\mathrm{\πd}}_{th}^2}---\left(11\right)$

Calculate minimum range s between throat's wall of cylindrical air exhaust nozzle by formula (12)₁：

$s_1=\frac{{\mathrm{\πd}}_s}{n_h}-d_{th}---\left(12\right)$

Calculate exhaust nozzle distance s by formula (13)₂：

$s_2=\frac{{\mathrm{\πd}}_s}{n_h}=s_1+d_{th}---\left(13\right);$

From 0 ° to 180 °, its cross-sectional area is equably reduced to minimum area from maximum area to aerofluxuss collector, arbitrarily angled Cross sectional radius r at position_βCalculate by formula (14)；

The two halves of aerofluxuss collector are full symmetric；

Aerofluxuss introduce area jet nozzle inside radius increment △ rs and press formula (15) calculating：

${\mathrm{\Δr}}_s=\sqrt{\frac{A_{th}{\mathrm{\ϵ}}_h+A_t{\mathrm{\ϵ}}_s}{\mathrm{\π}}}-\sqrt{\frac{A_t{\mathrm{\ϵ}}_s}{\mathrm{\π}}}---\left(15\right)$

Other area jet nozzle inside radius increment △ rx press formula (16) and calculate：

${\mathrm{\Δr}}_x=\sqrt{\frac{A_{th}{\mathrm{\ϵ}}_h+A_t{\mathrm{\ϵ}}_x}{\mathrm{\π}}}-\sqrt{\frac{A_t{\mathrm{\ϵ}}_x}{\mathrm{\π}}}---\left(16\right);$

Wherein each alphabetical implication is as follows：

A_if1Import bend pipe area, m²；

A_thThe exhaust nozzle throat gross area, m²；

A_ehExhaust nozzle exports the gross area, m²；

d_thThroat's internal diameter of exhaust nozzle, m²；

d_sAerofluxuss enter the thrust chamber jet pipe internal diameter at section, m²；

C_dhExhaust nozzle discharge coefficient；

dif₁Import bend pipe diameter, m；

Entropy index is determined in k aerofluxuss；

Ma₁Exhaust entrance Mach number；

p_eThe main gaseous-pressure of thrust chamber nozzle exit, Pa；

p_teExhaust entrance pressure, Pa；

n_hThe quantity of exhaust nozzle；

p_te ^*Exhaust entrance stagnation pressure, Pa；

q_mteExhaust mass flow, kg/s；

R exhaust gas constant, J/kg s；

s₁Minimum range between throat's wall of exhaust nozzle；

s₂Distance between exhaust nozzle；

r_phExhaust nozzle pressure ratio；

T_teExhaust inlet temperature, K；

T_te ^*Exhaust entrance stagnation temperature, K；

ξ_pImport is to the aerofluxuss total pressure loss coefficient of exhaust nozzle entrance；

r_phExhaust nozzle faces pressure ratio；

r_phcrExhaust nozzle faces critical pressure ratio；

r_βCross sectional radius at any angular position；

△r_sAerofluxuss introduce area jet nozzle inside radius increment；

△r_xArbitrary section jet pipe inside radius increment；

ε_hThe divergence ratio of exhaust nozzle；

ε_sJet pipe extension entrance divergence ratio；

ε_xArbitrary section jet pipe extension entrance divergence ratio；

b₂The minimum cross-section radius of aerofluxuss collector, m.

2. gaseous film control jet pipe according to claim 1 it is characterised in that：Also include cone cylinder (4), described cone cylinder (4) is solid It is scheduled on ring flange (5), described cone cylinder (4) is located in jet pipe extension, the radius of a circle residing for described cone cylinder (4) is less than aerofluxuss Radius of a circle residing for nozzle.

3. gaseous film control jet pipe according to claim 2 it is characterised in that：The inner mold face of described cone cylinder (4) arrival end with The inner mold face of the jet pipe leading portion port of export is consistent.

4. gaseous film control jet pipe according to claim 1 it is characterised in that：The other end of described inlet bend (3) and whirlpool Wheel exhaustor connects.

5. gaseous film control jet pipe according to claim 4 it is characterised in that：Described exhaust nozzle is velocity of sound exhaust nozzle.

6. gaseous film control jet pipe according to claim 5 it is characterised in that：The diameter of described jet pipe extension (6) is along low The flow direction of wet body is gradually increased.

7. gaseous film control jet pipe according to claim 6 it is characterised in that：The section of described exhaust nozzle is circular or long Circular.