CN101539480A - One-dimensional evaluation method of combustion efficiency for scramjet engine - Google Patents

Abstract

A one-dimensional evaluation method of combustion efficiency for scramjet engine relate to an evaluation method of combustion efficiency for engine. The method realizes quick evaluation for economic performance in combustion condition; and the application range of the existing one-dimensional evaluation method is enlarged so as to have universality. The method has the following steps: the entry condition and pressure distribution are ensured; the initial value eta0 of combustion efficiency is given; each component mass fraction g at the section of combustion chamber is ensured; the combustion mixture temperature Tkc is ensured; the combustion mixture enthalpy value Hkc and average molecular weight mukc are calculated; the local sound velocity a and mach number M at the section of combustion chamber are calculated; the friction coefficient cf at the wall surface of combustion chamber and the dissipative force X0 along flow direction are ensured; the combustion mixture flow speed velocity w, the heat current qw at the wall surface of combustion chamber and the calculated value eta of combustion efficiency are calculated; and whether the combustion efficiency is the same as the initial value is judged. The application of the method can quickly analyze ultrasonic speed combustion efficiency and related thermal and pneumatic parameters, and finally obtains one-dimensional distribution rule of combustion efficiency and related parameters along axial direction of combustion chamber.

Description

The one-dimensional evaluation method of the burning efficiency of scramjet engine

Technical field

The present invention relates to a kind of evaluation method of burning efficiency of engine, be specifically related to a kind of one-dimensional evaluation method of scramjet engine combustion chambers burn efficient.

Background technology

Three kinds of research and development means of scramjet engine are respectively ground experiment, flight test and numerical simulation at present.Ground experiment is basic means, must possess the ability of incoming flow component, stagnation pressure, stagnation temperature and speed under the simulation practical flight condition, and experimental facilities, analogy method, measuring technique, data processing etc. are had relatively high expectations; The flight test cost is huge, needs perfect ground safeguard system, as last checking means; Numerical simulation provides the detailed flow characteristics in whole flow field, but the machine duration, the calculating convergence depends on design conditions, and numerical simulation is difficult to realize completely.One-dimensional evaluation method overcomes above difficulty, can realize the quick analysis to test findings.

Burning efficiency has developed many cover evaluation methods as the important indicator of engine evaluated performance through research for many years.Each method is not all having unified standard aspect range of application, applicable elements and the accuracy at present, exists big uncertain in the practical application.Owing to there is the limitation of self, need several evaluation methods to replenish mutually in the practical application, development is constantly perfect mutually.In the engineering, ONE-DIMENSIONAL METHOD has often been ignored some original factors that exist, and has limited the universality of method to a certain extent.Summary is got up, and has following limitative proposition in the previous methods: burning mixes gas as desirable homogeneous gas processing, and specific heat and specific heat ratio are taken as constant; Ignore wall friction and heat-absorbing action; Do not consider that fuel injects working medium flow, momentum and effect of energy change.Real working condition is complicated and changeable in the firing chamber, does not strictly observe certain or several hypothesis, therefore according to actual conditions, in conjunction with the experimental measurement data, breaks through and abovely limits the judge that realizes burning efficiency and have the practical application meaning.The purpose of research is the scope of application that enlarges one-dimensional evaluation method, and manages to make it to have universality.

Burning efficiency can not directly be measured, and need obtain by treated conversion after measuring some parameters.Reliable measurement data is wall pressure, balance data and heat flow data (although the heat flow measurement precision is poor slightly) in the experiment.Find the solution one dimension when flowing system of equations, if the firing chamber profile determines, wall static pressure, heat flux distribution are known, and the factor that then influences burning efficiency will comprise mean molecular weight, specific heat at constant pressure and the wall friction power of gas along journey of mixing.One-dimensional evaluation method is applied to strong combustion conditions, has suitable confidence level in the uniform relatively flow field part (rear portion, firing chamber) of air-flow.

Summary of the invention

The one-dimensional evaluation method that the purpose of this invention is to provide a kind of burning efficiency of scramjet engine, burning efficiency and the associated hot of utilizing this method can obtain fast in the combustion process are moved and pneumatic parameter distributions rule, thereby realize the rapid evaluation to the combustion conditions economic performance; And enlarge the scope of application of existing one-dimensional evaluation method and make it to have universality.

Technical scheme of the present invention is: the one-dimensional evaluation method of the burning efficiency of scramjet engine of the present invention is realized according to following steps:

Step 1, determine entry of combustion chamber condition and pressure distribution: obtain the ultra-combustion ramjet combustion-chamber wall surface pressure distribution situation by test or numerical simulation, set up the molecular weight and the enthalpy database of each component in the firing chamber according to Physical Property Analysis software (for example ASPEN), set up the funtcional relationship μ (p that molecular weight and enthalpy and pressure, temperature and potpourri are formed, T, α) and H (p, T, α); Known combustion chamber inlet total mass flow rate and the shared mark of each composition are determined G _τ, G _o, L _{O τ}, α, H _BX ^*And I _BXUtilize the mutual conversion between burning efficiency and each constituent mass mark, the fundamental equation group coupling that the simultaneous equation of momentum (S12), energy equation (S04), flow equation (S08) and the equation of gas state (S09) constitute is found the solution, and above-mentioned four fundamental equations are shown in (1) to (4) formula:

$I_{\mathrm{BX}}+\underset{F_{\mathrm{\σok}}}{\∫}{p}_{\mathrm{kc}}d\stackrel{\‾}{F}-X_o=I_{\mathrm{kc}}=G_{\mathrm{\Σ}}{w}_{\mathrm{kc}}+p_{\mathrm{kc}}{F}_{\mathrm{kc}}---\left(1\right)$

$H_{\mathrm{BX}}^{*}-\frac{Q}{G_{\mathrm{\&Sigma;}}}=g_{\mathrm{\&tau;kc}}{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)+g_{\mathrm{okc}}{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)+g_{\mathrm{nckc}}{H}_{\mathrm{nc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)+\frac{{\mathrm{<figure-callout\; id="2"\; label="w\; kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">w</figure-callout>}}_{\mathrm{kc}}^{}}{2}---\left(2\right)$

${\mathrm{\&rho;}}_{\mathrm{BX}}{w}_{\mathrm{BX}}=\frac{\mathrm{\&alpha;}{L}_{\mathrm{o\&tau;}}}{1+\mathrm{\&alpha;}{L}_{\mathrm{o\&tau;}}}{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}{\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}---\left(3\right)$

$p_{\mathrm{kc}}={\mathrm{\&rho;}}_{\mathrm{kc}}\frac{R}{{\mathrm{\&mu;}}_{\mathrm{kc}}}{T}_{\mathrm{kc}}---\left(4\right)$

Wherein, I is a momentum; X _oBe firing chamber streamwise dissipative force; G _∑Be total working medium mass rate; F is an area, F _KcFor relative cross-section amasss, F _Kc=F _Kc/ F _BX(p, T are than enthalpy function α) to H, special H _BX ^*Be the total specific enthalpy of entry of combustion chamber; Q is the combustion chamber wall surface hot-fluid; G is a massfraction; (p, T α) are the molecular weight function to μ; L _{O τ}Be the chemical equivalent coefficient of oxygenant to fuel; α is that oxygenant is crossed oxygen quotient $\mathrm{\&alpha;}=\frac{G_o}{G_{\mathrm{\&tau;}}{L}_{\mathrm{o\&tau;}}},$ G _τAnd G _oBe respectively actual given fuel and oxygenant mass rate; W is a refrigerant flow rate in the firing chamber; R is a universal gas constant; ρ is a working medium density; T represents static temperature (firing chamber potpourri static temperature);

Wherein, the leftover bits and pieces target is explained: a certain section in " kc " expression firing chamber, " BX " expression entrance section place, " σ ok " expression combustion chamber side wall, " τ " represents fuel bed, " o " expression oxygenant layer, " nc " expression products of combustion layer; The a certain section fuel bed in footnote " τ kc " expression firing chamber, variable " μ _Kc" expression ignition mixture mean molecular weight, F _KcBe a certain section cross-sectional area in firing chamber;

Step 2, provide burning efficiency initial value η ₀:

$\mathrm{\&eta;}=\frac{{\mathrm{\&eta;}}_{\mathrm{npak}}}{{\mathrm{\&eta;}}_{\mathrm{meop}}}=\frac{G_{\mathrm{\&tau;cz}}}{{\stackrel{\&OverBar;}{G}}_{\mathrm{\&tau;}}}=\frac{G_{\mathrm{ocz}}}{{\stackrel{\&OverBar;}{G}}_o}---\left(5\right)$

Step 3, determine each composition quality mark g of section of combustion chamber:

$g_{\mathrm{\&tau;kc}}=\frac{G_{\mathrm{\&tau;}}-G_{\mathrm{\&tau;cz}}}{G_{\mathrm{\&Sigma;}}}=g_{\mathrm{\&tau;}}(1-{\mathrm{\&eta;}}_0{\mathrm{\&alpha;}}^v)---\left(6\right)$

$g_{\mathrm{okc}}=\frac{G_o-G_{\mathrm{ocz}}}{G_{\mathrm{\&Sigma;}}}=g_o(1-{\mathrm{\&eta;}}_0{\mathrm{\&alpha;}}^{v-1})---\left(7\right)$

$g_{\mathrm{nckc}}=\frac{G_{\mathrm{\&tau;cz}}+G_{\mathrm{ocz}}}{G_{\mathrm{\&Sigma;}}}={\mathrm{\&eta;}}_0(g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v+g_o{\mathrm{\&alpha;}}^{v-1})---\left(8\right)$

$\frac{1}{{\mathrm{\&mu;}}_{\mathrm{kc}}}=\frac{g_{\mathrm{\&tau;kc}}}{{\mathrm{\&mu;}}_{\mathrm{\&tau;kc}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)}+\frac{g_{\mathrm{okc}}}{{\mathrm{\&mu;}}_{\mathrm{okc}}(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)}+\frac{g_{\mathrm{nckc}}}{{\mathrm{\&mu;}}_{\mathrm{nckc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)}---\left(9\right)$

Wherein, η _NpakBe real reaction efficient; η _MeopBe theoretical reaction efficiency; η is the calculating burning efficiency of combustion effec tiveness definition; G _τAnd G _oWhen being respectively fuel perfect combustion, fuel that should react and oxygenant mass rate in theory; G _{τ cz}And G _OczBe respectively real reaction intact fuel and oxygenant mass rate; V is a design factor, regulation α≤1, v=1; α 〉=1, v=0;

Step 4, determine the ignition mixture temperature: determine the ignition mixture temperature T in conjunction with the equation of gas state (4) formula and (9) formula;

Step 5, obtain ignition mixture enthalpy and mean molecular weight μ _Kc:

Draw ignition mixture enthalpy and inlet ignition mixture mean molecular weight in conjunction with rerum natura analysis software ASPEN;

Step 6, obtain section of combustion chamber local velocity of sound a and Mach number M:

Obtain section of combustion chamber local velocity of sound and Mach number in conjunction with the equation of momentum (1) formula, flow equation (3) formula;

Step 7, determine combustion chamber wall surface friction factor c _fAnd streamwise dissipative force X _o:

Draw combustion chamber wall surface friction factor and streamwise dissipative force in conjunction with the equation of momentum (1) formula, flow equation (3) formula;

Step 8, obtain ignition mixture flow velocity w:

Step 9, obtain combustion chamber wall surface hot-fluid q _w:

Step 10, obtain burning efficiency calculated value η:

In conjunction with energy equation (2) formula and (6) to (8) formula, obtain burning efficiency calculating formula (24) formula:

$\mathrm{\&eta;}=\frac{H_{\mathrm{BX}}^{*}-\frac{Q}{G_{\mathrm{\&Sigma;}}}-g_o{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)-g_{\mathrm{\&tau;}}{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)-\frac{{\mathrm{<figure-callout\; id="2"\; label="w\; kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">w</figure-callout>}}_{\mathrm{kc}}^{}}{2}}{(g_o{\mathrm{\&alpha;}}^{v-1}+g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v)H_{\mathrm{nc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)-g_o{\mathrm{\&alpha;}}^{v-1}{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)-g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)}---\left(24\right)$

Wherein the combustion chamber wall surface hot-fluid calculates and adopts the Reynolds method of approximation:

$Q=\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}{q}_{w}d{F}_{\mathrm{\&sigma;ok}}---\left(25\right)$

$q_w=\frac{{\mathrm{<figure-callout\; id="2"\; label="c\; f"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">c</figure-callout>}}_f}{2}{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}S\left(I\right)(H_r-H_w)---\left(26\right)$

$S\left(I\right)=\frac{{2q}_w}{c_f{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}(H_r-H_w)}---\left(27\right)$

$H_r=H_{\mathrm{kc}}+r\frac{w_{\mathrm{<figure-callout\; id="2"\; label="kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">kc</figure-callout>}}^2}{2}---\left(28\right)$

Wherein, S (I) is the reynolds analogue parameter; H _rFor recovering enthalpy; H _wBe wall gas enthalpy; q _wBe combustion chamber wall surface unit's hot-fluid;

Step 11, judge whether burning efficiency is identical with initial value;

Compare η and given initial value η ₀Whether identical, if then execution in step 12; Otherwise get back to step 2, loop iteration is until the burning efficiency numerical value η that is met accuracy requirement;

Step 12, end.

The invention has the beneficial effects as follows: application this method can to burning efficiency and associated hot be moving and aerodynamic parameter carries out express-analysis, and finally obtains the burning efficiency and the correlation parameter one dimension regularity of distribution axial along the firing chamber.This method is introduced the true component of the mixed gas of burning and is calculated, and considers wall friction according to the actual conditions of combustion process, wall hot-fluid, the influence that fuel mass adds; Compare with existing ONE-DIMENSIONAL METHOD, on the basis of Actual combustion operating mode, widened the scope of application of method, thereby realize rapid evaluation the combustion process economic performance.This method at first obtains scramjet engine burning test data or emulated data, with the known parameters of chamber wall surface pressure as computation model; Consider that the actual combustion gas component in firing chamber is divided into fuel bed, oxygenant layer and products of combustion layer with computation model; Using the mobile system of equations combination model layering calculating of one dimension then finds the solution; Obtain finally that burning efficiency in the supersonic speed combustion process and heat are moving, the situation of change of aerodynamic parameter.

Description of drawings

Fig. 1 is this method scramjet engine burning efficiency calculation process block diagram, and Fig. 2 is each calculation of parameter thinking block diagram of scramjet engine burning efficiency one-dimensional evaluation method, and Fig. 3 is that (long measure of firing chamber is foot to the test combustion chamber structural representation; 1 is fuel injector, and 2 is cooling jacket, and 3 is ACTUATOR), (horizontal ordinate is the length of firing chamber to the pressure measuring value figure that Fig. 4 tests for hydrogen in the firing chamber-air burning, and unit is a rice; Ordinate is a force value, and unit is Mpa), Fig. 5 a be Mach number along the chamber long scatter chart and average fit value figure (horizontal ordinate is the length of firing chamber, and unit is a rice, and ordinate be a Mach numerical value; The solid line that has square is a curve map, and the solid line that does not have square is match value figure), Fig. 5 b be static temperature along the chamber long scatter chart and average fit value figure (horizontal ordinate is the length of firing chamber, and unit is a rice, and ordinate is the static temperature value, and unit is Kelvin; The solid line that has square is a curve map, and the solid line that does not have square is match value figure), Fig. 5 c be the ignition mixture mean molecular weight along the chamber long scatter chart and average fit value figure (horizontal ordinate is the length of firing chamber, and unit is a rice; Ordinate is the ignition mixture mean molecular weight; Here result of calculation is relative molecular weight, and unit is 1); The solid line that has square is a curve map, and the solid line that does not have square is match value figure), Fig. 5 d be burning efficiency along the chamber long scatter chart and average fit value figure (horizontal ordinate is the length of firing chamber, and unit is a rice; Ordinate is a burning efficiency; The solid line that has square is a curve map, and the solid line that does not have square is match value figure).

Embodiment

Embodiment one: as shown in Figure 1, the one-dimensional evaluation method of the burning efficiency of the described scramjet engine of present embodiment is realized according to following steps:

Step 1, determine entry of combustion chamber condition and pressure distribution: obtain the ultra-combustion ramjet combustion-chamber wall surface pressure distribution situation by test or numerical simulation, set up the molecular weight and the enthalpy database of each component in the firing chamber according to Physical Property Analysis software (for example ASPEN), set up the funtcional relationship μ (p that molecular weight and enthalpy and pressure, temperature and potpourri are formed, T, α) and H (p, T, α); Known combustion chamber inlet total mass flow rate and the shared mark of each composition are determined G _τ, G _o, L _{O τ}, α, H _BX ^*And I _BXUtilize the mutual conversion between burning efficiency and each constituent mass mark, the fundamental equation group coupling that the simultaneous equation of momentum (S12), energy equation (S04), flow equation (S08) and the equation of gas state (S09) constitute is found the solution, and above-mentioned four fundamental equations are shown in (1) to (4) formula:

$I_{\mathrm{BX}}+\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}{p}_{\mathrm{kc}}d\stackrel{\&OverBar;}{F}-X_o=I_{\mathrm{kc}}=G_{\mathrm{\&Sigma;}}{w}_{\mathrm{kc}}+p_{\mathrm{kc}}{F}_{\mathrm{kc}}---\left(1\right)$

$H_{\mathrm{BX}}^{*}-\frac{Q}{G_{\mathrm{\&Sigma;}}}=g_{\mathrm{\&tau;kc}}{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)+g_{\mathrm{okc}}{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)+g_{\mathrm{nckc}}{H}_{\mathrm{nc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)+\frac{{\mathrm{<figure-callout\; id="2"\; label="w\; kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">w</figure-callout>}}_{\mathrm{kc}}^{}}{2}---\left(2\right)$

${\mathrm{\&rho;}}_{\mathrm{BX}}{w}_{\mathrm{BX}}=\frac{\mathrm{\&alpha;}{L}_{\mathrm{o\&tau;}}}{1+\mathrm{\&alpha;}{L}_{\mathrm{o\&tau;}}}{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}{\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}---\left(3\right)$

$p_{\mathrm{kc}}={\mathrm{\&rho;}}_{\mathrm{kc}}\frac{R}{{\mathrm{\&mu;}}_{\mathrm{kc}}}{T}_{\mathrm{kc}}---\left(4\right)$

Wherein, I is a momentum; X _oBe firing chamber streamwise dissipative force; G _∑Be total working medium mass rate; F is an area, F _KcFor relative cross-section amasss, F _Kc=F _Kc/ F _BX(p, T are than enthalpy function α) to H, special H _BX ^*Be the total specific enthalpy of entry of combustion chamber; Q is the combustion chamber wall surface hot-fluid; G is a massfraction; (p, T α) are the molecular weight function to μ; L _{O τ}Be the chemical equivalent coefficient of oxygenant to fuel; α is that oxygenant is crossed oxygen quotient $\mathrm{\&alpha;}=\frac{G_o}{G_{\mathrm{\&tau;}}{L}_{\mathrm{o\&tau;}}},$ G _τAnd G _oBe respectively actual given fuel and oxygenant mass rate; W is a refrigerant flow rate in the firing chamber; R is a universal gas constant; ρ is a working medium density; T represents static temperature (firing chamber potpourri static temperature);

Wherein, the leftover bits and pieces target is explained: a certain section in " kc " expression firing chamber, " BX " expression entrance section place, " σ ok " expression combustion chamber side wall, " τ " represents fuel bed, " o " expression oxygenant layer, " nc " expression products of combustion layer; The a certain section fuel bed in footnote " τ kc " expression firing chamber, variable " μ _Kc" expression ignition mixture mean molecular weight, F _KcBe a certain section cross-sectional area in firing chamber;

Step 2, provide burning efficiency initial value η ₀:

$\mathrm{\&eta;}=\frac{{\mathrm{\&eta;}}_{\mathrm{npak}}}{{\mathrm{\&eta;}}_{\mathrm{meop}}}=\frac{G_{\mathrm{\&tau;cz}}}{{\stackrel{\&OverBar;}{G}}_{\mathrm{\&tau;}}}=\frac{G_{\mathrm{ocz}}}{{\stackrel{\&OverBar;}{G}}_o}---\left(5\right)$

Step 3, determine each composition quality mark g of section of combustion chamber:

$g_{\mathrm{\&tau;kc}}=\frac{G_{\mathrm{\&tau;}}-G_{\mathrm{\&tau;cz}}}{G_{\mathrm{\&Sigma;}}}=g_{\mathrm{\&tau;}}(1-{\mathrm{\&eta;}}_0{\mathrm{\&alpha;}}^v)---\left(6\right)$

$g_{\mathrm{okc}}=\frac{G_o-G_{\mathrm{ocz}}}{G_{\mathrm{\&Sigma;}}}=g_o(1-{\mathrm{\&eta;}}_0{\mathrm{\&alpha;}}^{v-1})---\left(7\right)$

$g_{\mathrm{nckc}}=\frac{G_{\mathrm{\&tau;cz}}+G_{\mathrm{ocz}}}{G_{\mathrm{\&Sigma;}}}={\mathrm{\&eta;}}_0(g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v+g_o{\mathrm{\&alpha;}}^{v-1})---\left(8\right)$

$\frac{1}{{\mathrm{\&mu;}}_{\mathrm{kc}}}=\frac{g_{\mathrm{\&tau;kc}}}{{\mathrm{\&mu;}}_{\mathrm{\&tau;kc}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)}+\frac{g_{\mathrm{okc}}}{{\mathrm{\&mu;}}_{\mathrm{okc}}(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)}+\frac{g_{\mathrm{nckc}}}{{\mathrm{\&mu;}}_{\mathrm{nckc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)}---\left(9\right)$

Wherein, η _NpakBe real reaction efficient; η _MeopBe theoretical reaction efficiency; η is the calculating burning efficiency of combustion effec tiveness definition; G _τAnd G _oWhen being respectively fuel perfect combustion, fuel that should react and oxygenant mass rate in theory; G _{τ cz}And G _OczBe respectively real reaction intact fuel and oxygenant mass rate; V is a design factor, regulation α≤1, v=1; α 〉=1, v=0;

Step 4, determine the ignition mixture temperature: determine the ignition mixture temperature T in conjunction with the equation of gas state (4) formula and (9) formula;

Step 5, obtain ignition mixture enthalpy and mean molecular weight μ _Kc:

Draw ignition mixture enthalpy and inlet ignition mixture mean molecular weight in conjunction with rerum natura analysis software ASPEN;

Step 6, obtain section of combustion chamber local velocity of sound a and Mach number M:

Obtain section of combustion chamber local velocity of sound and Mach number in conjunction with the equation of momentum (1) formula, flow equation (3) formula;

Step 7, determine combustion chamber wall surface friction factor c _fAnd streamwise dissipative force X _o:

Draw combustion chamber wall surface friction factor and streamwise dissipative force in conjunction with the equation of momentum (1) formula, flow equation (3) formula;

Step 8, obtain ignition mixture flow velocity w:

Step 9, obtain combustion chamber wall surface hot-fluid q _w:

Step 10, obtain burning efficiency calculated value η:

In conjunction with energy equation (2) formula and (6) to (8) formula, obtain burning efficiency calculating formula (24) formula:

$\mathrm{\&eta;}=\frac{H_{\mathrm{BX}}^{*}-\frac{Q}{G_{\mathrm{\&Sigma;}}}-g_o{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)-g_{\mathrm{\&tau;}}{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)-\frac{{\mathrm{<figure-callout\; id="2"\; label="w\; kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">w</figure-callout>}}_{\mathrm{kc}}^{}}{2}}{(g_o{\mathrm{\&alpha;}}^{v-1}+g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v)H_{\mathrm{nc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)-g_o{\mathrm{\&alpha;}}^{v-1}{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)-g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)}---\left(24\right)$

Wherein the combustion chamber wall surface hot-fluid calculates and adopts the Reynolds method of approximation:

$Q=\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}{q}_{w}d{F}_{\mathrm{\&sigma;ok}}---\left(25\right)$

$q_w=\frac{{\mathrm{<figure-callout\; id="2"\; label="c\; f"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">c</figure-callout>}}_f}{2}{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}S\left(I\right)(H_r-H_w)---\left(26\right)$

$S\left(I\right)=\frac{{2q}_w}{c_f{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}(H_r-H_w)}---\left(27\right)$

$H_r=H_{\mathrm{kc}}+\mathrm{<figure-callout\; id="2"\; label="r\; w\; kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">r</figure-callout>}\frac{w_{\mathrm{kc}}^{}}{}\frac{{}_2^{}}{2}---\left(28\right)$

Wherein, S (I) is the reynolds analogue parameter; H _rFor recovering enthalpy; H _wBe wall gas enthalpy; q _wBe combustion chamber wall surface unit's hot-fluid;

Step 11, judge whether burning efficiency is identical with initial value:

Compare η and given initial value η ₀Whether identical, if then execution in step 12; Otherwise get back to step 2, loop iteration is until the burning efficiency numerical value η that is met accuracy requirement;

Step 12, end.

Embodiment two: in step 6, section of combustion chamber local velocity of sound and Mach number calculate the balance dissociating gas method that adopts in the present embodiment:

H _kc＝g _τkcH _τ(p _τkc，T _kc，α＝0)+g _okcH _o(p _okc，T _kc，α＝∞)+g _nckcH _nc(p _nckc，T _kc，α＝1) (10)

$c_p={\left(\frac{{\&PartialD;H}_{\mathrm{kc}}}{{\&PartialD;T}_{\mathrm{kc}}}\right)}_{p_{\mathrm{kc}}}---\left(11\right)$

$c_v=c_p-\frac{R{[1-{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln T_{\mathrm{kc}}}\right)}_{p_{\mathrm{kc}}}]}^2}{{\mathrm{\&mu;}}_{\mathrm{kc}}[1+{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln p_{\mathrm{kc}}}\right)}_{T_{\mathrm{kc}}}]}---\left(12\right)$

$k=\frac{c_p}{c_v}---\left(13\right)$

$a_{\mathrm{kc}}=\sqrt{\frac{{\mathrm{kRT}}_{\mathrm{kc}}}{{\mathrm{\&mu;}}_{\mathrm{kc}}[1+{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln p_{\mathrm{kc}}}\right)}_{T_{\mathrm{kc}}}]}}---\left(14\right)$

M _kc＝w _kc/a _kc (15)

Wherein, H _KcBe a certain section burning in firing chamber mixture specific enthalpy; c _pBe specific heat at constant pressure; c _vBe specific heat at constant volume; K is a specific heat ratio; M is a Mach number; A is a local velocity of sound.

Embodiment three: present embodiment is in step 7, and dull and stereotyped no gradient turbulent boundary layer semiempirical formula is adopted in described combustion chamber wall surface friction loss:

$\frac{0.242\sqrt{1-\mathrm{\&omega;}-\mathrm{\&beta;}}}{\sqrt{c_f}\sqrt{\mathrm{\&beta;}}}[\arcsin \frac{\sqrt{\mathrm{\&beta;}}+\frac{\mathrm{\&omega;}}{2\sqrt{\mathrm{\&beta;}}}}{\sqrt{1+\frac{{\mathrm{\&omega;}}^2}{4\mathrm{\&beta;}}}}-\arcsin \frac{\frac{\mathrm{\&omega;}}{2\sqrt{\mathrm{\&beta;}}}}{\sqrt{1+\frac{{\mathrm{\&omega;}}^2}{4\mathrm{\&beta;}}}}]=0.41+1g\left(R_{\mathrm{ex}}{c}_f\right)-1g\left(\frac{{\mathrm{\&mu;}}_w}{{\mathrm{\&mu;}}_e}\right)---\left(16\right)$

$\mathrm{\&beta;}=r\frac{k-1}{2}{M}_{\mathrm{kc}}^2\frac{T_{\mathrm{kc}}}{T_w}---\left(17\right)$

$T_r=T_{\mathrm{kc}}(1+r\frac{k-1}{2}{M}_{\mathrm{kc}}^2)---\left(18\right)$

$\mathrm{\&omega;}=1-\frac{T_r}{T_w}---\left(19\right)$

$\frac{{\mathrm{\&mu;}}_w}{{\mathrm{\&mu;}}_e}={\left(\frac{T_w}{T_{\mathrm{kc}}}\right)}^n---\left(20\right)$

$X_{\mathrm{mp}}=\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}\frac{1}{2}{c}_f{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}^{2}d{F}_{\mathrm{\&sigma;ok}}---\left(21\right)$

X _o＝X _n+X _mp (22)

$p_{\mathrm{BX}}+{\mathrm{\&rho;}}_{\mathrm{<figure-callout\; id="2"\; label="BX\; w\; BX"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">BX</figure-callout>}}{w}_{\mathrm{BX}}^{}{}_2^{}+\frac{p_{\mathrm{BX}}+p_{\mathrm{kc}}}{2}({\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}-1)-X_o/F_{\mathrm{BX}}={\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}(p_{\mathrm{kc}}+{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}^2)---\left(23\right)$

Wherein, ω and β are the computation process intermediate quantity; T _rBe recovery temperature, r is a coefficient of restitution; T _wBe the chamber wall surface temperature; R _ExBe the Reynolds number under the current coordinate; c _fBe the wall friction coefficient; X _nBe fuel oil support plate aerodynamic drag (can by cold conditions air inlet test determination); X _MpBe combustion chamber wall surface friction force;

Be the ratio of near wall kinetic viscosity with the outer gas stream kinetic viscosity, n is an index, and n can be by test determination.

Embodiment: shown in Fig. 1～5d, the one-dimensional evaluation method of the burning efficiency of the scramjet engine that the present invention proposes, it respectively calculates thinking as shown in Figure 1.For obtaining parameter distribution situation along the chamber length direction, suitable computational length to be chosen along the chamber length direction in the firing chamber carry out segmentation calculating, the calculation of parameter situation of each section is as follows:

1, obtains the ultra-combustion ramjet combustion-chamber wall surface pressure distribution situation by test or numerical simulation, set up the molecular weight (S01) and enthalpy (S02) database of each component in the firing chamber according to Physical Property Analysis software (ASPEN), set up the funtcional relationship μ (p that molecular weight and enthalpy and pressure, temperature and potpourri are formed, T, α) and H (p, T, α) (each physical quantity meaning such as following);

2, known combustion chamber inlet total mass flow rate and the shared mark of each composition (can be determined G thus _τ, G _o, L _{O τ}, α, H _BX ^*, I _BXEach physical quantity meaning is as described below), utilize the mutual conversion between burning efficiency and each constituent mass number percent, the fundamental equation group coupling that the simultaneous equation of momentum (S12), energy equation (S04), flow equation (S08) and the equation of gas state (S09) (being respectively (1) to (4) formula) constitute is found the solution, and fundamental equation is following to be shown:

$I_{\mathrm{BX}}+\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}{p}_{\mathrm{kc}}d\stackrel{\&OverBar;}{F}-X_o=I_{\mathrm{kc}}=G_{\mathrm{\&Sigma;}}{w}_{\mathrm{kc}}+p_{\mathrm{kc}}{F}_{\mathrm{kc}}---\left(1\right)$

$H_{\mathrm{BX}}^{*}-\frac{Q}{G_{\mathrm{\&Sigma;}}}=g_{\mathrm{\&tau;kc}}{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)+g_{\mathrm{okc}}{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)+g_{\mathrm{nckc}}{H}_{\mathrm{nc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)+\frac{{\mathrm{<figure-callout\; id="2"\; label="w\; kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">w</figure-callout>}}_{\mathrm{kc}}^{}}{2}---\left(2\right)$

${\mathrm{\&rho;}}_{\mathrm{BX}}{w}_{\mathrm{BX}}=\frac{\mathrm{\&alpha;}{L}_{\mathrm{o\&tau;}}}{1+\mathrm{\&alpha;}{L}_{\mathrm{o\&tau;}}}{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}{\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}---\left(3\right)$

$p_{\mathrm{kc}}={\mathrm{\&rho;}}_{\mathrm{kc}}\frac{R}{{\mathrm{\&mu;}}_{\mathrm{kc}}}{T}_{\mathrm{kc}}---\left(4\right)$

Wherein, I is a momentum; X _oBe firing chamber streamwise dissipative force; G _∑Be total mass flow rate; F is an area, F _KcFor relative cross-section amasss, F _Kc=F _Kc/ F _BX(p, T are than enthalpy function α) to H, special H _BX ^*Be the total specific enthalpy of entry of combustion chamber (segmentation is to calculate the moving parameter of gained heat, the total specific enthalpy of this that calculates section inlet according to the preceding paragraph in calculating); Q is the combustion chamber wall surface hot-fluid; G is a massfraction; (p, T α) are the molecular weight function to μ; L _{O τ}Be the chemical equivalent coefficient of oxygenant to fuel; α is that oxygenant is crossed oxygen quotient, $\mathrm{\&alpha;}=\frac{G_o}{G_{\mathrm{\&tau;}}{L}_{\mathrm{o\&tau;}}},$ G _τAnd G _oBe respectively actual given fuel and oxygenant mass rate; W is a refrigerant flow rate in the firing chamber; R is a universal gas constant; ρ is a working medium density; T represents static temperature (firing chamber potpourri static temperature);

Wherein, explanation to footnote: a certain section in " kc " expression firing chamber, " BX " expression entrance section place, " σ ok " represents sidewall, " τ " represents fuel bed, " o " expression oxygenant layer, " nc " expression products of combustion layer, for example footnote " τ kc " is represented a certain section fuel bed in firing chamber, variable " μ _Kc" expression ignition mixture mean molecular weight, F _KcBe a certain section cross-sectional area in firing chamber;

Calculate the moving and aerodynamic parameter of burning efficiency and associated hot, calculation process as depicted in figs. 1 and 2:

(a), provide burning efficiency initial value η ₀(burning efficiency defines suc as formula (5)) determines each composition quality mark of section of combustion chamber ((6) to (8) formula) (S03).(S09) reach (9) formula in conjunction with the equation of gas state ((4) formula), determine inlet ignition mixture mean molecular weight (S05) and ignition mixture temperature;

$\mathrm{\&eta;}=\frac{{\mathrm{\&eta;}}_{\mathrm{npak}}}{{\mathrm{\&eta;}}_{\mathrm{meop}}}=\frac{G_{\mathrm{\&tau;cz}}}{{\stackrel{\&OverBar;}{G}}_{\mathrm{\&tau;}}}=\frac{G_{\mathrm{ocz}}}{{\stackrel{\&OverBar;}{G}}_o}---\left(5\right)$

$g_{\mathrm{\&tau;kc}}=\frac{G_{\mathrm{\&tau;}}-G_{\mathrm{\&tau;cz}}}{G_{\mathrm{\&Sigma;}}}=g_{\mathrm{\&tau;}}(1-{\mathrm{\&eta;}}_0{\mathrm{\&alpha;}}^v)---\left(6\right)$

$g_{\mathrm{okc}}=\frac{G_o-G_{\mathrm{ocz}}}{G_{\mathrm{\&Sigma;}}}=g_o(1-{\mathrm{\&eta;}}_0{\mathrm{\&alpha;}}^{v-1})---\left(7\right)$

$g_{\mathrm{nckc}}=\frac{G_{\mathrm{\&tau;cz}}+G_{\mathrm{ocz}}}{G_{\mathrm{\&Sigma;}}}={\mathrm{\&eta;}}_0(g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v+g_o{\mathrm{\&alpha;}}^{v-1})---\left(8\right)$

$\frac{1}{{\mathrm{\&mu;}}_{\mathrm{kc}}}=\frac{g_{\mathrm{\&tau;kc}}}{{\mathrm{\&mu;}}_{\mathrm{\&tau;kc}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)}+\frac{g_{\mathrm{okc}}}{{\mathrm{\&mu;}}_{\mathrm{okc}}(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)}+\frac{g_{\mathrm{nckc}}}{{\mathrm{\&mu;}}_{\mathrm{nckc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)}---\left(9\right)$

Wherein, η _NpakBe real reaction efficient; η _MeopBe theoretical reaction efficiency; η is the calculating burning efficiency of combustion effec tiveness definition; G _τAnd G _oWhen being respectively fuel perfect combustion, fuel that should react and oxygenant mass rate in theory; G _{τ cz}And G _OczBe respectively real reaction intact fuel and oxygenant mass rate; V is a design factor, regulation α≤1, v=1; α 〉=1, v=0;

(b), in conjunction with the equation of momentum ((1) formula) (S12), flow equation ((3) formula) (S08), section of combustion chamber local velocity of sound (S07) and Mach number (S10) calculating formula ((10) to (15) formula) and combustion chamber wall surface tribometer formula ((16) to (23) formula) obtain firing chamber mixture velocity and combustion chamber wall surface friction factor (S11);

(I), section of combustion chamber local velocity of sound and Mach number calculate the balance dissociating gas method that adopts:

H _kc＝g _τkcH _τ(p _τkc，T _kc，α＝0)+g _okcH _o(p _okc，T _kc，α＝∞)+g _nckcH _nc(p _nckc，T _kc，α＝1) (10)

$c_p={\left(\frac{{\&PartialD;H}_{\mathrm{kc}}}{{\&PartialD;T}_{\mathrm{kc}}}\right)}_{p_{\mathrm{kc}}}---\left(11\right)$

$c_v=c_p-\frac{R{[1-{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln T_{\mathrm{kc}}}\right)}_{p_{\mathrm{kc}}}]}^2}{{\mathrm{\&mu;}}_{\mathrm{kc}}[1+{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln p_{\mathrm{kc}}}\right)}_{T_{\mathrm{kc}}}]}---\left(12\right)$

$k=\frac{c_p}{c_v}---\left(13\right)$

$a_{\mathrm{kc}}=\sqrt{\frac{{\mathrm{kRT}}_{\mathrm{kc}}}{{\mathrm{\&mu;}}_{\mathrm{kc}}[1+{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln p_{\mathrm{kc}}}\right)}_{T_{\mathrm{kc}}}]}}---\left(14\right)$

M _kc＝w _kc/a _kc (15)

Wherein, H _KcBe a certain section burning in firing chamber mixture specific enthalpy; c _pBe specific heat at constant pressure; c _vBe specific heat at constant volume; K is a specific heat ratio; M is a Mach number; A is a local velocity of sound; Each footnote implication as described above.

(II), the semiempirical formula of dull and stereotyped no gradient turbulent boundary layer is adopted in the combustion chamber wall surface friction loss:

$\frac{0.242\sqrt{1-\mathrm{\&omega;}-\mathrm{\&beta;}}}{\sqrt{c_f}\sqrt{\mathrm{\&beta;}}}[\arcsin \frac{\sqrt{\mathrm{\&beta;}}+\frac{\mathrm{\&omega;}}{2\sqrt{\mathrm{\&beta;}}}}{\sqrt{1+\frac{{\mathrm{\&omega;}}^2}{4\mathrm{\&beta;}}}}-\arcsin \frac{\frac{\mathrm{\&omega;}}{2\sqrt{\mathrm{\&beta;}}}}{\sqrt{1+\frac{{\mathrm{\&omega;}}^2}{4\mathrm{\&beta;}}}}]=0.41+1g\left(R_{\mathrm{ex}}{c}_f\right)-1g\left(\frac{{\mathrm{\&mu;}}_w}{{\mathrm{\&mu;}}_e}\right)---\left(16\right)$

$\mathrm{\&beta;}=r\frac{k-1}{2}{M}_{\mathrm{kc}}^2\frac{T_{\mathrm{kc}}}{T_w}---\left(17\right)$

$T_r=T_{\mathrm{kc}}(1+r\frac{k-1}{2}{M}_{\mathrm{kc}}^2)---\left(18\right)$

$\mathrm{\&omega;}=1-\frac{T_r}{T_w}---\left(19\right)$

$\frac{{\mathrm{\&mu;}}_w}{{\mathrm{\&mu;}}_e}={\left(\frac{T_w}{T_{\mathrm{kc}}}\right)}^n---\left(20\right)$

$X_{\mathrm{mp}}=\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}\frac{1}{2}{c}_f{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}^{2}d{F}_{\mathrm{\&sigma;ok}}---\left(21\right)$

X _o＝X _n+X _mp (22)

$p_{\mathrm{BX}}+{\mathrm{\&rho;}}_{\mathrm{<figure-callout\; id="2"\; label="BX\; w\; BX"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">BX</figure-callout>}}{w}_{\mathrm{BX}}^{}{}_2^{}+\frac{p_{\mathrm{BX}}+p_{\mathrm{kc}}}{2}({\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}-1)-X_o/F_{\mathrm{BX}}={\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}(p_{\mathrm{kc}}+{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}^2)---\left(23\right)$

Wherein, ω and β are the computation process intermediate quantity; T _rBe recovery temperature, r is a coefficient of restitution; T _wBe the chamber wall surface temperature; R _ExBe the Reynolds number under the current coordinate; c _fBe the wall friction coefficient; X _nBe fuel oil support plate aerodynamic drag (can by cold conditions air inlet test determination); X _MpBe combustion chamber wall surface friction force;

Be the ratio of near wall kinetic viscosity with the outer gas stream kinetic viscosity, n is index (can by test determination);

(c), (S04) and (6) to (8) formula, obtain burning efficiency calculating formula ((24) formula), more given initial value η in conjunction with energy equation ((2) formula) ₀, loop iteration, to the burning efficiency numerical value η that is met accuracy requirement:

$\mathrm{\&eta;}=\frac{H_{\mathrm{BX}}^{*}-\frac{Q}{G_{\mathrm{\&Sigma;}}}-g_o{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)-g_{\mathrm{\&tau;}}{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)-\frac{{\mathrm{<figure-callout\; id="2"\; label="w\; kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">w</figure-callout>}}_{\mathrm{kc}}^{}}{2}}{(g_o{\mathrm{\&alpha;}}^{v-1}+g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v)H_{\mathrm{nc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)-g_o{\mathrm{\&alpha;}}^{v-1}{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)-g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)}---\left(24\right)$

Wherein combustion chamber wall surface hot-fluid (S13) calculates and adopts the Reynolds method of approximation:

$Q=\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}{q}_{w}d{F}_{\mathrm{\&sigma;ok}}---\left(25\right)$

$q_w=\frac{{\mathrm{<figure-callout\; id="2"\; label="c\; f"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">c</figure-callout>}}_f}{2}{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}s\left(I\right)(H_r-H_w)---\left(26\right)$

$S\left(I\right)=\frac{{2q}_w}{c_f{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}(H_r-H_w)}---\left(27\right)$

$H_r=H_{\mathrm{kc}}+\mathrm{<figure-callout\; id="2"\; label="r\; w\; kc"\; filenames="A20091007193200252.png"\; state="\{\{state\}\}">r</figure-callout>}\frac{w_{\mathrm{kc}}^{}}{}\frac{{}_2^{}}{2}---\left(28\right)$

Wherein, S (I) is the reynolds analogue parameter; H _rFor recovering enthalpy; H _wBe wall gas enthalpy; q _wBe combustion chamber wall surface unit's hot-fluid.

Find the solution by each computing module loop iteration, finally can be met the parameters such as burning efficiency, stagnation temperature, Mach number and each composition quality mark of working medium in the firing chamber of computational accuracy, and calculate by segmentation, choose suitable computational length, can obtain each and ask the parameter distribution situation long along the chamber.

3, result of calculation is utilized in the firing chamber each component of potpourri or heat is moving, aerodynamic parameter is verified, is compared by numerical simulation value or experiment measuring value and Model Calculation value.Adopt test unit to be the anterior scramjet engine firing chamber that has the area diffuser pipe, it is made up of fuel injector, cooling jacket, ACTUATOR, test section and measurement mechanism, test combustion chamber structural representation such as Fig. 3.Wherein, entry of combustion chamber area 0.0038m ², discharge area 0.0076m ², employing hydrogen is fuel, chemical equivalent coefficient L _Or=34.2.Hydrogen fuel is sprayed by sonic nozzle, mass rate 21.1g/s; The entry of combustion chamber incoming flow is pure air, mass rate 1.4458kg/s.The pressure measuring value of hydrogen in the firing chamber-air burning test as shown in Figure 4.Verify as Fig. 5 with experiment measuring value (seeing Table 1), and, therefore choose air-flow flow field part (rear portion, firing chamber) checking relatively uniformly and have suitable confidence level because one-dimensional evaluation method is applied to strong combustion conditions.Adopt this method, outlet combustion efficiency value that calculates and known measurements compare, and relative error is 0.38%; The temperature relative error is 0.91%; The Mach number relative error is 0.18%.

Moving and the pneumatic supplemental characteristic of table 1 experimental measurement combustor exit cross section heat

The position (in, cm)	w(ft/s，m/s)	T(°R，K)	Tt(°R，K)	M	η
						35.00(88.90)	6476(1974)	3934(2186)	6813(3785)	2.17	0.94

The unit of all parameters all adopts international unit among the present invention.

Claims (3)

1, a kind of one-dimensional evaluation method of burning efficiency of scramjet engine is characterized in that: described evaluation method realizes according to following steps:

Step 1, determine entry of combustion chamber condition and pressure distribution: obtain the ultra-combustion ramjet combustion-chamber wall surface pressure distribution situation by test or numerical simulation, set up the molecular weight and the enthalpy database of each component in the firing chamber according to Physical Property Analysis software, set up the funtcional relationship μ (p that molecular weight and enthalpy and pressure, temperature and potpourri are formed, T, α) and H (p, T, α); Known combustion chamber inlet total mass flow rate and the shared mark of each composition are determined G _τ, G _o, L _{O τ}, α, H _BX ^*And I _BX, utilizing the mutual conversion between burning efficiency and each constituent mass mark, the fundamental equation group coupling that the simultaneous equation of momentum, energy equation, flow equation and the equation of gas state constitute is found the solution, and above-mentioned four fundamental equations are shown in (1) to (4) formula:

$I_{\mathrm{BX}}+\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}{p}_{\mathrm{kc}}d\stackrel{\&RightArrow;}{F}{-X}_o=I_{\mathrm{kc}}=G_{\mathrm{\&Sigma;}}{w}_{\mathrm{kc}}+p_{\mathrm{kc}}{F}_{\mathrm{kc}}---\left(1\right)$

$H_{\mathrm{BX}}^{*}-\frac{Q}{G_{\mathrm{\&Sigma;}}}=g_{\mathrm{\&tau;kc}}{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)+g_{\mathrm{okc}}{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)+g_{\mathrm{nckc}}{H}_{\mathrm{nc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)+\frac{w_{\mathrm{kc}}^2}{2}---\left(2\right)$

${\mathrm{\&rho;}}_{\mathrm{BX}}{w}_{\mathrm{BX}}=\frac{\mathrm{\&alpha;}{L}_{\mathrm{o\&tau;}}}{1+\mathrm{\&alpha;}{L}_{\mathrm{o\&tau;}}}{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}{\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}---\left(3\right)$

$p_{\mathrm{kc}}={\mathrm{\&rho;}}_{\mathrm{kc}}\frac{R}{{\mathrm{\&mu;}}_{\mathrm{kc}}}{T}_{\mathrm{kc}}---\left(4\right)$

Wherein, I is a momentum; X _oBe firing chamber streamwise dissipative force; G _∑Be total working medium mass rate; F is an area, F _KcFor relative cross-section amasss, F _Kc=F _Kc/ F _BX(p, T are than enthalpy function α) to H, special H _BX ^*Be the total specific enthalpy of entry of combustion chamber; Q is the combustion chamber wall surface hot-fluid; G is a massfraction; (p, T α) are the molecular weight function to μ; L _{O τ}Be the chemical equivalent coefficient of oxygenant to fuel; α is that oxygenant is crossed oxygen quotient $\mathrm{\&alpha;}=\frac{G_o}{G_{\mathrm{\&tau;}}{L}_{\mathrm{o\&tau;}}},$ G _τAnd G _oBe respectively actual given fuel and oxygenant mass rate; W is a refrigerant flow rate in the firing chamber; R is a universal gas constant; ρ is a working medium density; T represents static temperature;

Wherein, the leftover bits and pieces target is explained: a certain section in " kc " expression firing chamber, " BX " expression entrance section place, " σ ok " expression combustion chamber side wall, " τ " represents fuel bed, " o " expression oxygenant layer, " nc " expression products of combustion layer; The a certain section fuel bed in footnote " τ kc " expression firing chamber, variable " μ _Kc" expression ignition mixture mean molecular weight, F _KcBe a certain section cross-sectional area in firing chamber;

Step 2, provide burning efficiency initial value η ₀:

$\mathrm{\&eta;}=\frac{{\mathrm{\&eta;}}_{\mathrm{npak}}}{{\mathrm{\&eta;}}_{\mathrm{meop}}}=\frac{G_{\mathrm{\&tau;cz}}}{{\stackrel{\&OverBar;}{G}}_{\mathrm{\&tau;}}}=\frac{G_{\mathrm{ocz}}}{{\stackrel{\&OverBar;}{G}}_o}---\left(5\right)$

Step 3, determine each composition quality mark g of section of combustion chamber:

$g_{\mathrm{\&tau;kc}}=\frac{G_{\mathrm{\&tau;}}-G_{\mathrm{\&tau;cz}}}{G_{\mathrm{\&Sigma;}}}=g_{\mathrm{\&tau;}}(1-{\mathrm{\&eta;}}_0{\mathrm{\&alpha;}}^v)---\left(6\right)$

$g_{\mathrm{okc}}=\frac{G_o-G_{\mathrm{ocz}}}{G_{\mathrm{\&Sigma;}}}=g_o(1-{\mathrm{\&eta;}}_0{\mathrm{\&alpha;}}^{v-1})---\left(7\right)$

$g_{\mathrm{nckc}}=\frac{G_{\mathrm{\&tau;cz}}+G_{\mathrm{ocz}}}{G_{\mathrm{\&Sigma;}}}={\mathrm{\&eta;}}_0(g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v+g_o{\mathrm{\&alpha;}}^{v-1})---\left(8\right)$

$\frac{1}{{\mathrm{\&mu;}}_{\mathrm{kc}}}=\frac{g_{\mathrm{\&tau;kc}}}{{\mathrm{\&mu;}}_{\mathrm{\&tau;kc}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)}+\frac{g_{\mathrm{okc}}}{{\mathrm{\&mu;}}_{\mathrm{okc}}(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)}+\frac{g_{\mathrm{nckc}}}{{\mathrm{\&mu;}}_{\mathrm{nckc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)}---\left(9\right)$

Wherein, η _NpakBe real reaction efficient; η _MeopBe theoretical reaction efficiency; η is the calculating burning efficiency of combustion effec tiveness definition; G _τAnd G _oWhen being respectively fuel perfect combustion, fuel that should react and oxygenant mass rate in theory; G _{τ cz}And G _OczBe respectively real reaction intact fuel and oxygenant mass rate; V is a design factor, regulation α≤1, v=1; α 〉=1, v=0;

Step 4, determine the ignition mixture temperature: determine the ignition mixture temperature T in conjunction with the equation of gas state (4) formula and (9) formula;

Step 5, obtain ignition mixture enthalpy and mean molecular weight μ _Kc:

Draw ignition mixture enthalpy and inlet ignition mixture mean molecular weight in conjunction with rerum natura analysis software ASPEN;

Step 6, obtain section of combustion chamber local velocity of sound a and Mach number M:

Obtain section of combustion chamber local velocity of sound and Mach number in conjunction with the equation of momentum (1) formula, flow equation (3) formula;

Step 7, determine combustion chamber wall surface friction factor c _fAnd streamwise dissipative force X _o:

Draw combustion chamber wall surface friction factor and streamwise dissipative force in conjunction with the equation of momentum (1) formula, flow equation (3) formula;

Step 8, obtain ignition mixture flow velocity w:

Step 9, obtain combustion chamber wall surface hot-fluid q _w:

Step 10, obtain burning efficiency calculated value η:

In conjunction with energy equation (2) formula and (6) to (8) formula, obtain burning efficiency calculating formula (24) formula:

$\mathrm{\&eta;}=\frac{H_{\mathrm{BX}}^{*}-\frac{Q}{G_{\mathrm{\&Sigma;}}}-g_o{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)-g_{\mathrm{\&tau;}}{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)-\frac{w_{\mathrm{kc}}^2}{2}}{(g_o{\mathrm{\&alpha;}}^{v-1}+g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v)H_{\mathrm{nc}}(p_{\mathrm{nckc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=1)-g_o{\mathrm{\&alpha;}}^{v-1}{H}_o(p_{\mathrm{okc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=\&infin;)-g_{\mathrm{\&tau;}}{\mathrm{\&alpha;}}^v{H}_{\mathrm{\&tau;}}(p_{\mathrm{\&tau;kc}},T_{\mathrm{kc}},\mathrm{\&alpha;}=0)}---\left(24\right)$

Wherein the combustion chamber wall surface hot-fluid calculates and adopts the Reynolds method of approximation:

$Q=\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}{q}_{w}d{F}_{\mathrm{\&sigma;ok}}---\left(25\right)$

$q_w=\frac{c_f}{2}{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}S\left(I\right)(H_r-H_w)---\left(26\right)$

$S\left(I\right)=\frac{2q_w}{c_f{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}(H_r-H_w)}---\left(27\right)$

$H_r=H_{\mathrm{kc}}+r\frac{w_{\mathrm{kc}}^2}{2}---\left(28\right)$

Wherein, S (I) is the reynolds analogue parameter; H _rFor recovering enthalpy; H _wBe wall gas enthalpy; q _wBe combustion chamber wall surface unit's hot-fluid;

Step 11, judge whether burning efficiency is identical with initial value:

Compare η and given initial value η ₀Whether identical, if then execution in step 12; Otherwise get back to step 2, loop iteration is until the burning efficiency numerical value η that is met accuracy requirement;

Step 12, end.

2, the one-dimensional evaluation method of the burning efficiency of scramjet engine according to claim 1 is characterized in that: in the step 6, section of combustion chamber local velocity of sound and Mach number calculate the balance dissociating gas method that adopts:

H _kc＝g _τkcH _τ(p _τkc，T _kc，α＝0)+g _okcH _o(p _okc，T _kc，α＝∞)+g _nckcH _nc(p _nckc，T _kc，α＝1)(10)

$c_p={\left(\frac{{\&PartialD;H}_{\mathrm{kc}}}{{\&PartialD;T}_{\mathrm{kc}}}\right)}_{p_{\mathrm{kc}}}---\left(11\right)$

$c_v=c_p-\frac{R{[1-{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln T_{\mathrm{kc}}}\right)}_{p_{\mathrm{kc}}}]}^2}{{\mathrm{\&mu;}}_{\mathrm{kc}}[1+{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln p_{\mathrm{kc}}}\right)}_{T_{\mathrm{kc}}}]}---\left(12\right)$

$k=\frac{c_p}{c_v}---\left(13\right)$

$a_{\mathrm{kc}}=\sqrt{\frac{\mathrm{kR}{T}_{\mathrm{kc}}}{{\mathrm{\&mu;}}_{\mathrm{kc}}[1+{\left(\frac{\&PartialD;\ln {\mathrm{\&mu;}}_{\mathrm{kc}}}{\&PartialD;\ln p_{\mathrm{kc}}}\right)}_{T_{\mathrm{kc}}}]}}---\left(14\right)$

M _kc＝w _kc/a _c (15)

Wherein, H _KcBe a certain section burning in firing chamber mixture specific enthalpy; c _pBe specific heat at constant pressure; c _vBe specific heat at constant volume; K is a specific heat ratio; M is a Mach number; A is a local velocity of sound.

3, the one-dimensional evaluation method of the burning efficiency of scramjet engine according to claim 1 is characterized in that: in the step 7, the semiempirical formula of dull and stereotyped no gradient turbulent boundary layer is adopted in the combustion chamber wall surface friction loss:

$\frac{0.242\sqrt{1-\mathrm{\&omega;}-\mathrm{\&beta;}}}{\sqrt{c_f}\sqrt{\mathrm{\&beta;}}}[\arcsin \frac{\sqrt{\mathrm{\&beta;}}+\frac{\mathrm{\&omega;}}{2\sqrt{\mathrm{\&beta;}}}}{\sqrt{1+\frac{{\mathrm{\&omega;}}^2}{4\mathrm{\&beta;}}}}-\arcsin \frac{\frac{\mathrm{\&omega;}}{2\sqrt{\mathrm{\&beta;}}}}{\sqrt{1+\frac{{\mathrm{\&omega;}}^2}{4\mathrm{\&beta;}}}}]=0.41+\lg \left(R_{\mathrm{ex}}{c}_f\right)-\lg \left(\frac{{\mathrm{\&mu;}}_w}{{\mathrm{\&mu;}}_e}\right)---\left(16\right)$

$\mathrm{\&beta;}=r\frac{k-1}{2}{M}_{\mathrm{kc}}^2\frac{T_{\mathrm{kc}}}{T_w}---\left(17\right)$

$T_r=T_{\mathrm{kc}}(1+r\frac{k-1}{2}{M}_{\mathrm{kc}}^2)---\left(18\right)$

$\mathrm{\&omega;}=1-\frac{T_r}{T_w}---\left(19\right)$

$\frac{{\mathrm{\&mu;}}_w}{{\mathrm{\&mu;}}_e}={\left(\frac{T_w}{T_{\mathrm{kc}}}\right)}^n---\left(20\right)$

$X_{\mathrm{mp}}=\underset{F_{\mathrm{\&sigma;ok}}}{\&Integral;}\frac{1}{2}{c}_f{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}^{2}d{F}_{\mathrm{\&sigma;ok}}---\left(21\right)$

X _o＝X _n+X _mp (22)

$p_{\mathrm{BX}}+{\mathrm{\&rho;}}_{\mathrm{BX}}{w}_{\mathrm{BX}}^2+\frac{p_{\mathrm{BX}}+p_{\mathrm{kc}}}{2}({\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}-1)-X_o/F_{\mathrm{BX}}={\stackrel{\&OverBar;}{F}}_{\mathrm{kc}}(p_{\mathrm{kc}}+{\mathrm{\&rho;}}_{\mathrm{kc}}{w}_{\mathrm{kc}}^2)---\left(23\right)$

Wherein, ω and β are the computation process intermediate quantity; T _rBe recovery temperature, r is a coefficient of restitution; T _wBe the chamber wall surface temperature; R _ExBe the Reynolds number under the current coordinate; c _fBe the wall friction coefficient; X _nBe fuel oil support plate aerodynamic drag; X _MpBe combustion chamber wall surface friction force; Be the ratio of near wall kinetic viscosity with the outer gas stream kinetic viscosity, n is an index, and n is by test determination.

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