CN108182297B - Rocket engine combustion chamber efficiency analysis method and system - Google Patents
Rocket engine combustion chamber efficiency analysis method and system Download PDFInfo
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Abstract
The invention discloses a rocket engine combustion chamber efficiency analysis method and a rocket engine combustion chamber efficiency analysis system. The invention more accurately realizes the analysis of the efficiency of the combustion chamber and provides more accurate basis for the performance evaluation comparison of different working conditions and different engines of the same engine.
Description
Technical Field
The invention relates to the field of rocket engines, in particular to a method and a system for analyzing the efficiency of a combustion chamber of a rocket engine.
Background
The combustion chamber efficiency is an important parameter for evaluating the performance of the engine, and in the process of developing the engine, the combustion chamber efficiency and the nozzle efficiency of the engine need to be obtained through engine hot test examination, wherein the nozzle efficiency is obtained through calculation based on the specific impulse of the engine and the combustion chamber efficiency, so that the combustion chamber efficiency of the engine is accurately obtained, and the method is very important for accurately evaluating the performance of the engine and improving or determining the design of the engine.
At present, in the hot test run of an engine, the efficiency of a combustion chamber cannot be directly measured, but is obtained by measuring parameters such as the diameter of the throat part of the engine before the test run, the pressure of the combustion chamber, the flow rate of a propellant and the like in the test run process and then calculating according to the following formula:
from the calculation formula, the combustion chamber efficiency has no relation with the engine operating temperature. However, due to the effect of expansion with heat and contraction with cold of the material, when the actual engine works, the temperature of the throat part reaches over 1000 ℃, the diameter of the throat part is generally larger than the diameter value measured at normal temperature before test run, so that the flow rate of the propellant generating the same combustion chamber pressure is larger than that before expansion, therefore, the efficiency of the combustion chamber obtained by the method is generally lower than the true value, and if the temperature of the throat part reaches 1200 ℃, the linear expansion coefficient of the material is 8 e-6/DEG C, the result is calculated by the traditional method to deviate from the true value by nearly 2%. On the other hand, the throat temperature stabilization time is generally longer than the flow and pressure stabilization time when the engine works, the diameter of the throat of the combustion chamber is changed before the throat temperature is stabilized, and the combustion chamber efficiency obtained at the stage is not a true value. It is noted that the higher the throat temperature, the greater the deviation of the combustion chamber efficiency calculated by the conventional method from the true value, which in turn causes the deviation of the nozzle efficiency calculated based on the combustion chamber efficiency from the true value in the same proportion. Therefore, when the working temperature of the same engine is different due to the difference of working conditions or different working temperatures of different engines are different, the combustion chamber efficiency and the nozzle efficiency obtained by the traditional method cannot truly reflect the difference, and therefore the improvement and confirmation of the design state of the engine are misled.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides a method and a system for analyzing the efficiency of a combustion chamber of a rocket engine, which provide accurate basis for evaluating and comparing the performance of the same engine under different working conditions and different engines.
The purpose of the invention is realized by the following technical scheme: a rocket engine combustion chamber efficiency analysis system comprises
Data acquisition module for performing normal temperature T0Lower engine throat diameter Dt0Corresponding linear expansion coefficient alpha of combustion chamber material and engine combustion chamber pressure P during engine thermal testc(t), oxidizer and fuel mass flow rate qmo(t) and qmf(T) and throat temperature Tt(t) collecting;
the data average value calculation module is used for obtaining the average value of each parameter of the engine through a preset algorithm to obtain the average value of the pressure in the combustion chamberAverage mass flow of oxidant and fuelAndmean value of throat temperature
A throat diameter calculation module for, according to a preset formula:diameter D of throat portion of engine during operationtCalculating (1); wherein alpha is the linear expansion coefficient of the combustion chamber base material at the corresponding temperature;
a mixing ratio calculation module for, according to a preset formula: mixing ratioMixing ratio r of oxidant and fuel flowmCalculating (1);
an actual characteristic velocity calculation module for calculating a velocity based on the predictionThe formula is as follows:proceed to the actual characteristic speed C*Calculating (1); wherein D istIs the temperature corrected throat diameter;
theoretical characteristic velocity calculation module using combustion chamber pressureAnd mixing ratio rmCalculating theoretical characteristic speed according to the principle of minimum Gibbs free energy
An engine combustion chamber efficiency calculation module for passing a predetermined formulaEfficiency η of combustion chamber of enginecAnd (4) calculating.
The invention also provides a rocket engine combustion chamber efficiency analysis method, which comprises the following steps:
step 2, carrying out hot test of the engine, and acquiring the pressure P of the combustion chamber of the engine through a data acquisition modulec(t), oxidizer and fuel mass flow rates qmo(t) and qmf(T), throat temperature Tt(t);
Step 3, obtaining an arithmetic mean value of each parameter of the engine through a data mean value calculation module to obtain a mean value of the pressure in the combustion chamberAverage mass flow of oxidant and fuelAndmean value of throat temperature
Step 4, calculating the throat diameter D of the engine during working through a throat diameter calculation module by utilizing the average value of the throat temperaturet:
Wherein alpha is the linear expansion coefficient of the combustion chamber base material at the corresponding temperature;
and calculating the mixing ratio r by a mixing ratio calculation module according to the average flow of the oxidant and the fuelm:
Step 5, calculating the actual characteristic speed C through an actual characteristic speed calculation module*:
step 6, utilizing the pressure of the combustion chamberAnd mixing ratio rmCalculating the theoretical characteristic speed according to the minimum Gibbs free energy principle by a theoretical characteristic speed calculation module
Step 7, calculating the efficiency eta of the engine combustion chamber through an engine combustion chamber efficiency calculation modulec:
Wherein the temperature-corrected throat diameter is calculated by adopting a linear expansion coefficientWhen averaging all the parameters, in order to ensure that the parameters are taken from the same engine state, the average value calculation interval is the same time interval, and when averaging the parameters in the engine test run process, the length of the test run program is required to ensure that the parameters such as the pressure of a combustion chamber, the flow of oxidant and fuel, the throat temperature and the like have enough stable sections, and the length of the stable sections is not less than 5 s.
Compared with the prior art, the invention has the following beneficial effects:
in engine design, in order to obtain higher specific impact performance, it is necessary to organize more sufficient combustion to generate higher temperatures, and on the other hand, in order to reduce the requirements for high temperature resistant materials, it is desirable that the lower the engine operating temperature, the better. Therefore, the working temperature of the engine needs to be reduced as much as possible on the premise of not influencing the performance of the engine, and the performance of the engine needs to be evaluated through the efficiency of the combustion chamber during test of the short nozzle. According to the analysis, if the influence of the temperature on the throat diameter of the combustion chamber is not considered, the performance of the engine at higher temperature can be underestimated, so that misjudgment is formed on the temperature reduction design of the engine, and lower specific impulse performance of the engine can be obtained only when a full-size high-altitude simulation thermal test is carried out later. By the aid of the method for analyzing the efficiency of the combustion chamber, the performance of the engine can be accurately evaluated in a short nozzle examination stage by considering the influence of temperature, and development cost and period are remarkably saved.
Drawings
FIG. 1 is a schematic diagram of the change of the diameter of the throat part of the engine in the embodiment of the invention.
FIG. 2 is a graphical representation of engine operating parameters in accordance with an embodiment of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention. In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.
The embodiment of the invention provides a rocket engine combustion chamber efficiency analysis system, which comprises
Data acquisition module for performing normal temperature T0Lower engine throat diameter Dt0Corresponding linear expansion coefficient alpha of combustion chamber material and engine combustion chamber pressure P during engine thermal testc(t), oxidizer and fuel mass flow rate qmo(t) and qmf(T) and throat temperature Tt(t) collecting;
the data average value calculation module is used for obtaining the average value of each parameter of the engine through a preset algorithm to obtain the average value of the pressure in the combustion chamberAverage mass flow of oxidant and fuelAndmean value of throat temperature
A throat diameter calculation module for, according to a preset formula:diameter D of throat portion of engine during operationtCalculating (1); wherein alpha is the linear expansion coefficient of the combustion chamber base material at the corresponding temperature;
a mixing ratio calculation module for, according to a preset formula: mixing ratioMixing ratio r of oxidant and fuel flowmCalculating (1);
an actual characteristic velocity calculation module, configured to:proceed to the actual characteristic speed C*Calculating (1); wherein D istIs the temperature corrected throat diameter;
theoretical characteristic velocity calculation module using combustion chamber pressureAnd mixing ratio rmCalculating theoretical characteristic speed according to the principle of minimum Gibbs free energy
An engine combustion chamber efficiency calculation module for passing a predetermined formulaEfficiency η of combustion chamber of enginecAnd (4) calculating. The throat diameter after temperature correction is obtained by adopting linear expansion coefficient calculationWhen averaging all parameters, in order to ensure that the parameters are taken from the same engine state, the average value calculation interval is the same time interval, and when averaging the parameters in the engine test run process, the test run program length is required to ensure the pressure of a combustion chamber, the oxidant and the fuel flowAnd the throat temperature and other parameters have enough stable sections, and the length of each stable section is not less than 5 s.
FIG. 1 is a schematic diagram of a change in engine combustion chamber profile relative to a normal temperature condition under operating conditions. The solid line part of the graph is the profile of the combustion chamber at normal temperature, and the ambient temperature T can be measured before the test is started0Lower throat diameter Dt0. The dotted line is the state after the combustion chamber expands to generate radial and axial displacement under the working state, and the diameter of the throat part after expansion is D in the figuret。
Fig. 2 is a graph of engine combustion chamber pressure, propellant flow rate and throat temperature measured during the test, for convenience of illustration, throat temperature is plotted against the actual parameter of 0.1 and pressure data is plotted against the actual parameter of 10 times. Taking the average value of each parameter stable section between two virtual lines, and calculating according to the average value of the throat temperature and the linear expansion coefficient alpha of the material to obtain the throat diameter of
And calculating the characteristic speed and efficiency of the combustion chamber by using the throat diameter of the working state.
Examples
Taking a certain engine combustion chamber efficiency analysis as an example,
Step 2, acquiring data through a data acquisition module during engine test, wherein a relevant parameter curve is shown in figure 2, each parameter of the engine is stable after 40s according to the test parameter curve (figure 2), and taking the parameter in an interval of 40 s-48 s (between two vertical dotted lines in the figure);
step 3, carrying out average calculation on the obtained parameters through a data average calculation module to obtain the average value of the throat temperatureAverage oxidant flowAverage fuel flowMean value of combustion chamber pressure
And 4, calculating the throat diameter of the engine in a working state through a throat diameter calculation module according to the average value of the throat temperature:
Dt=18.00*(1+6e-6*(1612-25))=18.23mm
and 5, calculating the mixing ratio through a mixing ratio calculation module according to the average flow values of the oxidant and the fuel:
rm=93.2/56.6=1.647
and 6, calculating the actual characteristic speed of the engine through an actual characteristic speed calculation module according to the throat diameter, the combustion chamber pressure, the oxidant and the fuel flow under the working state of the engine:
and 7, calculating the theoretical characteristic speed of the engine through a theoretical characteristic speed calculation module according to the mixing ratio of the engine and the pressure of the combustion chamber:
C*=1742m/s
and 8, calculating the efficiency of the engine combustion chamber through an engine combustion chamber efficiency calculation module:
the foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.
Claims (4)
1. A rocket engine combustion chamber efficiency analysis system is characterized by comprising
Data acquisition module for performing normal temperature T0Lower engine throat diameter Dt0Corresponding linear expansion coefficient alpha of combustion chamber material and engine combustion chamber pressure P during engine thermal testc(t), oxidizer and fuel mass flow rate qmo(t) and qmf(T) and throat temperature Tt(t) collecting;
the data average value calculation module is used for obtaining the average value of each parameter of the engine through a preset algorithm to obtain the average value of the pressure in the combustion chamberAverage mass flow of oxidant and fuelAndmean value of throat temperature
A throat diameter calculation module for, according to a preset formula:diameter D of throat portion of engine during operationtCalculating (1); wherein alpha is the linear expansion coefficient of the combustion chamber base material at the corresponding temperature;
a mixing ratio calculation module for, according to a preset formula: mixing ratioMixing ratio r of oxidant and fuel flowmCalculating (1);
actual characteristic velocityThe calculation module is used for calculating the following parameters according to a preset formula:proceed to the actual characteristic speed C*Calculating (1); wherein D istIs the temperature corrected throat diameter;
theoretical characteristic velocity calculation module using combustion chamber pressureAnd mixing ratio rmCalculating theoretical characteristic speed according to the principle of minimum Gibbs free energy
2. A rocket engine combustion chamber efficiency analysis method is characterized by comprising the following steps:
step 1, collecting normal temperature T through a data collection module0Lower engine throat diameter Dt0Inquiring the linear expansion coefficient alpha of the corresponding combustion chamber material;
step 2, carrying out hot test of the engine, and acquiring the pressure P of the combustion chamber of the engine through a data acquisition modulec(t), oxidizer and fuel mass flow rates qmo(t) and qmf(T), throat temperature Tt(t);
Step 3, obtaining an arithmetic mean value of each parameter of the engine through a data mean value calculation module to obtain a mean value of the pressure in the combustion chamberAverage mass flow of oxidant and fuelAndmean value of throat temperature
Step 4, calculating the throat diameter D of the engine during working through a throat diameter calculation module by utilizing the average value of the throat temperaturet:
Wherein alpha is the linear expansion coefficient of the combustion chamber base material at the corresponding temperature;
and calculating the mixing ratio r by a mixing ratio calculation module according to the average value of the mass flow of the oxidant and the fuelm:
Step 5, calculating the actual characteristic speed C through an actual characteristic speed calculation module*:
step 6, utilizing the pressure of the combustion chamberAnd mixing ratio rmCalculating the theoretical characteristic speed according to the minimum Gibbs free energy principle by a theoretical characteristic speed calculation module
Step 7, calculating the efficiency eta of the engine combustion chamber through an engine combustion chamber efficiency calculation modulec:
3. A rocket engine combustion chamber efficiency analysis method according to claim 2, wherein when averaging each parameter, the average calculation interval is the same time interval in order to ensure that the parameters are taken from the same engine state.
4. A rocket engine combustion chamber efficiency analysis method according to claim 2, wherein when averaging parameters during engine commissioning, the length of commissioning procedure is required to ensure that there are sufficient stable sections of combustion chamber pressure, oxidant and fuel flow, throat temperature parameters, the stable section length being not less than 5 s.
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CN106134384B (en) * | 2012-03-31 | 2014-06-18 | 上海空间推进研究所 | The choosing method of rail control engine combustion chamber, a kind of space best features length |
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CN103116705A (en) * | 2013-02-06 | 2013-05-22 | 中国航天科技集团公司第六研究院第十一研究所 | Fault simulated analysis method for afterburning cycle rocket engine |
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互击式喷嘴燃烧室燃烧效率实验;张蒙正 等;《推进技术》;20120229;第33卷(第1期);全文 * |
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