Rapid prediction method for fuel gas component concentration of jet engine

Abstract

The invention provides a jet engine gas component concentration rapid prediction method comprising the following steps: determining a gas molecular weight according to a given gas constant; establishing a gas concentration-molecular weight correlation equation and a concentration sum equation according to the given type of each component of the gas and the molecular weight of the gas; if N2 (CO) exists in a given fuel gas component type, simplifying the N2 (CO) according to equal-concentration CO (N2), and combining the N2 (CO) with the original CO (N2) component to be marked as CO '(N2'); establishing a gas concentration-gas specific heat ratio correlation equation according to the given type of each component of the gas and the gas specific heat ratio; all the equations are combined, the combined equations are simplified through a Gaussian elimination method, and the concentration of each simplified fuel gas component meeting the error requirement is obtained through a Newton iteration method; and according to concentration weighting, inversely solving respective concentration proportions of N2 and CO which meet a given gas specific heat ratio and are not simplified, and obtaining a final original component concentration.

Description

Technical Field

[0001] The invention belongs to the technical field of prediction of fuel gas component concentration of a jet engine, and in particular relates to a method for quickly predicting the fuel gas component concentration of a jet engine. Background Art

[0002] Reaction Control System (RCS) is a direct force control system that uses the engine jet to generate reaction force to quickly change the motion attitude or trajectory of the aircraft. Its role is to supplement the inefficiency of aerodynamic control surfaces and quickly change the flight state. It has broad prospects for engineering applications. When the RCS jet enters the super / hypersonic outflow, it will interact with each other to form a complex shock wave / boundary layer interference flow field containing various flow phenomena such as boundary layer separation and reattachment, shock waves, expansion waves, Mach disks, shear layers, etc., and produce aerodynamic / thermal interference that varies strongly nonlinearly with jet parameters, flight conditions, layout forms, etc.

[0003] In recent years, new air defense and anti-missile weapons, hypersonic high-mobility strategic weapons, aerospace vehicles, etc. have developed rapidly. In order to meet the needs of stable control, high mobility, and precision strike, higher and higher requirements have been put forward for the prediction accuracy of RCS jet aerodynamic interference and the prediction of complex physical and chemical effects that are closer to the actual flight situation. The numerical calculation of the non-equilibrium flow field of thermal spray chemistry requires the concentration of each component of the gas as one of the input parameters. The engineering tasks often provide the temperature of the jet engine combustion chamber, the specific heat ratio of the gas, the gas constant of the gas, and the type of components (usually including N2, CO, CO2, H2O, etc.), but the concentration of the components is often difficult to accurately give.

[0004] The concentration of each fuel gas component determines the gas constant of the entire fuel gas, which together with the temperature determines the specific heat ratio of the entire fuel gas. Therefore, there is an urgent need for a rapid prediction method for the concentration of each fuel gas component based on a given fuel gas type, gas constant, temperature, and specific heat ratio to improve the processing efficiency of engineering tasks. Summary of the invention

[0005] In order to overcome the deficiencies in the prior art, the inventors have conducted intensive research and provided a method for quickly predicting the concentration of jet engine fuel gas components to solve the problem that the temperature of the jet engine combustion chamber, the specific heat ratio of the fuel gas, the gas constant of the fuel gas, and the type of components (usually including N2, CO, CO2, H2O, etc.) are known in engineering tasks, but the component concentrations are difficult to accurately determine.

[0006] The technical solution provided by the present invention is as follows:

[0007] In a first aspect, a method for rapidly predicting the concentration of fuel gas components in a jet engine comprises:

[0008] Determine the molecular weight of the fuel gas according to the given fuel gas constant;

[0009] According to the given gas component types and gas molecular weight, the gas concentration-molecular weight correlation equation and the concentration sum equation are established; if the given gas component types are greater than 3 and include both CO and N2, CO, CO2, and H2O are retained, and N2 is simplified as equal concentration CO, which is combined with the original CO component and recorded as CO'; if the given gas component types are greater than 3 and include both CO and N2, N2, CO2, and H2O are retained, and CO is simplified as equal concentration N2, which is combined with the original N2 component and recorded as N2';

[0010] According to the given gas component types and gas specific heat ratio, establish the gas concentration-gas specific heat ratio correlation equation;

[0011] The gas concentration-molecular weight correlation equation, the concentration and equation, and the gas concentration-gas specific heat ratio correlation equation are simultaneously established;

[0012] The combined equations are simplified by Gaussian elimination method, and the simplified concentrations of each gas component that meet the error requirements are obtained by Newton iteration method.

[0013] According to the concentration weighting, the concentration ratio of N2 and CO before simplification that meets the given gas specific heat ratio is inversely solved to obtain the final original component concentration.

[0014] In a second aspect, a rapid prediction device for the concentration of fuel gas components of a jet engine comprises:

[0015] one or more processors;

[0016] A storage device for storing one or more programs;

[0017] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for quickly predicting the concentration of fuel gas components in a jet engine as described in the first aspect.

[0018] In a third aspect, a readable storage medium stores a computer program, which, when executed by a processor, implements the method for quickly predicting the concentration of fuel gas components in a jet engine as described in the first aspect.

[0019] In a fourth aspect, a computer program product is provided, the computer program product comprising: a computer program (also referred to as code, or instruction), which, when executed, executes the method for rapidly predicting the concentration of fuel gas components of a jet engine as described in the first aspect.

[0020] A rapid prediction method for the concentration of fuel gas components in a jet engine provided by the present invention has the following beneficial effects:

[0021] (1) The present invention provides a method for rapidly predicting the concentration of fuel gas components of a jet engine. The method comprises the following steps: determining the molecular weight of fuel gas according to a given fuel gas constant; establishing a fuel gas concentration-molecular weight correlation equation and a concentration sum equation according to given fuel gas component types and fuel gas molecular weights; if N2(CO) exists in a given fuel gas component type, simplifying it as CO(N2) of equal concentration, and merging it with the original CO(N2) component and recording it as CO'(N2'); establishing a fuel gas concentration-fuel gas specific heat ratio correlation equation according to given fuel gas component types and fuel gas specific heat ratios; combining all the above equations, simplifying the combined equations by Gaussian elimination, and obtaining simplified fuel gas component concentrations that meet the error requirements by Newton iteration; and weighting the concentrations by inversely solving the concentration ratios of N2 and CO before simplification that meet the given fuel gas specific heat ratio to obtain the final original component concentrations. The present invention covers common fuel gas components containing C, H, O, and N elements, and can cover fuel gas components of most fuel engines used in engineering applications, thereby realizing rapid prediction of the concentrations of fuel gas components.

[0022] (2) The present invention provides a method for quickly predicting the concentration of fuel gas components in a jet engine. If N2(CO) exists in a given fuel gas component type, it is simplified and processed as an equal concentration CO(N2), which is combined with the original CO(N2) component and recorded as CO'(N2'). The two components of the same molecular weight, CO and N2, are combined and processed, which effectively saves the amount of calculation and improves the calculation efficiency.

[0023] (3) The present invention provides a method for quickly predicting the concentration of fuel gas components in a jet engine. The simplified CO'(N2') component is combined with other unsimplified components to calculate a new limiting fuel gas specific heat ratio. Taking a given fuel gas specific heat ratio as the target quantity, the component concentration ratios of CO and N2 before simplification that meet the requirements are obtained, and finally the concentrations of each fuel gas component are determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A flowchart of a method for rapidly predicting the concentration of fuel gas components in a jet engine;

[0025] Figure 2 This is the prediction result of the gas component concentration in the example. DETAILED DESCRIPTION

[0026] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0027] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0028] The present invention provides a method for quickly predicting the concentration of fuel gas components in a jet engine. Figure 1 As shown, the following steps are included:

[0029] Step (1), according to the given fuel gas constant, determine the fuel gas molecular weight, the specific formula is:

[0030] M=R u / R (1)

[0031] Where M represents the molecular weight of the gas; R u is the universal gas constant 8.314 J / (mol·K); R is the fuel gas constant.

[0032] Step (2), based on the given gas component types and gas molecular weight, taking the gas component concentration as the objective function, assuming that the gas contains n components, establish the gas concentration-molecular weight correlation equation and the concentration sum equation as follows:

[0033]

[0034] Where c i is the concentration of the i-th component in the gas, M i is the molecular weight of the i-th component in the fuel gas, i = 1, 2,…, n.

[0035] In this step, if the fuel gas component type includes both CO and N2, CO and N2 are combined and simplified into one gas, specifically:

[0036] If the number of given gas component types is greater than 3 and contains both CO and N2, then CO, CO2, and H2O are retained; N2 is simplified as equal concentration CO, and it is combined with the original CO component and recorded as CO'. Of course, it can also be: If the number of given gas component types is greater than 3 and contains both CO and N2, then N2, CO2, and H2O are retained; CO is simplified as equal concentration N2, and it is combined with the original N2 component and recorded as N2'.

[0037] Step (3), according to the given gas component types and gas specific heat ratio, establish the gas concentration-gas specific heat ratio correlation equation:

[0038]

[0039] C pi (T) = R i (A i +B i T+C i T 2 +D i T 3 +E i T 4 ) (4)

[0040] C vi (T) = R i (A i +B i T+C i T 2 +D i T 3 +E i T 4 -1)

[0041] Where γ(T) represents the specific heat ratio of the gas, C pi (T), C vi (T) are the specific heat at constant pressure and specific heat at constant volume of the i-th component in the gas, A i ,B i ,C i ,D i ,E i is the thermodynamic coefficient of the i-th component in the gas, R i is the gas constant of the i-th component in the fuel gas, and T represents the fuel gas temperature.

[0042] The simultaneous equations (2)-(4) are simplified by Gaussian elimination to obtain the component c i The relationship between the two is obtained by Newton iteration method, and the result of the last iteration step that meets the error requirements is obtained, which is the simplified component c i value.

[0043] Step (4) is to inversely calculate the concentration ratio of N2 and CO before simplification that meets the given gas specific heat ratio according to the concentration weighting, and obtain the final original component concentration. The specific process is as follows:

[0044] Replace the simplified CO' or N2' components with pure CO and pure N2, and obtain the limiting γ values ​​of the hypothetical gas 1 (containing only pure CO) and the hypothetical gas 2 (containing only pure N2) according to the formula (4) listed in step (3), which are denoted as γ1 and γ2 respectively. The given gas specific heat ratio is denoted as γ, which should satisfy:

[0045]

[0046] or

[0047] By calculating the above formula (5), the concentration values ​​of the components CO and N2 can be obtained, and the concentration values ​​of the original components can be fully predicted.

[0048] Based on the jet engine parameters given in Table 1 below, the present invention has carried out tests on the prediction of gas component concentration. The fast prediction method program developed is used for calculation. After 17 numerical iterations, the obtained component concentration is basically consistent with the given component concentration, and the error does not exceed 0.1%, which verifies the effectiveness of the present invention for fast prediction of jet engine gas component concentration. The results of each iteration are shown in Figure 2 .

[0049] Table 1

[0050]

[0051] The present invention also provides a device for quickly predicting the concentration of fuel gas components in a jet engine, comprising:

[0052] one or more processors;

[0053] a storage device for storing one or more programs,

[0054] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for quickly predicting the concentration of fuel gas components in a jet engine as described in the first aspect.

[0055] The present invention also provides a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for rapidly predicting the concentration of fuel gas components in a jet engine as described in the first aspect.

[0056] The readable storage medium includes, but is not limited to, various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0057] The present invention also provides a computer program product, which includes: a computer program (also referred to as code, or instruction), which, when executed, executes the method for rapidly predicting the concentration of fuel gas components in a jet engine as described in the first aspect.

[0058] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL) or wireless (e.g., infrared, microwave, etc.) mode to another website site, computer, server or data center.

[0059] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0060] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and modules can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0061] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0062] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for quickly predicting the concentration of fuel gas components in a jet engine, characterized in that: include: Determine the molecular weight of the fuel gas according to the given fuel gas constant; According to the given gas component types and gas molecular weight, establish the gas concentration-molecular weight correlation equation and concentration sum equation; If the fuel gas component type contains both CO and N2, CO and N2 are combined and simplified into one gas; According to the given gas component types and gas specific heat ratio, establish the gas concentration-gas specific heat ratio correlation equation; The gas concentration-molecular weight correlation equation, the concentration and equation, and the gas concentration-gas specific heat ratio correlation equation are simultaneously established; The combined equations are simplified by Gaussian elimination method, and the simplified concentrations of each gas component that meet the error requirements are obtained by Newton iteration method. According to the concentration weighting, the concentration ratio of N2 and CO before simplification that meets the given gas specific heat ratio is inversely solved to obtain the final original component concentration.

2. The method for rapid prediction of the concentration of fuel gas components in a jet engine according to claim 1, characterized in that: The step of determining the molecular weight of the fuel gas according to the given fuel gas constant is implemented in the following manner: M=R u / R Where M represents the molecular weight of the gas; R u is the universal gas constant 8.314 J / (mol·K); R is the fuel gas constant.

3. The method for rapid prediction of the concentration of fuel gas components in a jet engine according to claim 1, characterized in that: In the step of establishing the gas concentration-molecular weight correlation equation and the concentration sum equation according to the given gas component types and gas molecular weight, the gas concentration-molecular weight correlation equation is: The concentration and equation are: Where c i is the concentration of the i-th component in the gas, M i is the molecular weight of the i-th component in the fuel gas, i = 1, 2, ..., n, and n is the number of fuel gas component types.

4. The method for rapid prediction of the concentration of fuel gas components in a jet engine according to claim 1, characterized in that: In the step of establishing a gas concentration-gas specific heat ratio correlation equation according to the given gas component types and gas specific heat ratio, the gas concentration-gas specific heat ratio correlation equation is: C pi (T)=R i (A i +B i T+C i T 2 +D i T 3 +E i T 4 ) C vi (T)=R i (A i +B i T+C i T 2 +D i T 3 +E i T 4 -1) Where γ(T) represents the specific heat ratio of the gas, C pi (T), C vi (T) are the specific heat at constant pressure and specific heat at constant volume of the i-th component in the gas, A i ,B i ,C i ,D i ,E i is the thermodynamic coefficient of the i-th component in the gas, R i is the gas constant of the i-th component in the fuel gas, and T represents the fuel gas temperature.

5. The method for rapid prediction of the concentration of fuel gas components in a jet engine according to claim 1, characterized in that: The step of combining CO and N2 to simplify them into one gas if the fuel gas component type includes both CO and N2 is as follows: if the number of given fuel gas component types is greater than 3 and includes both CO and N2, CO, CO2, and H2O are retained, N2 is simplified as CO with equal concentration, and is combined with the original CO component to be recorded as CO'; or if the number of given fuel gas component types is greater than 3 and includes both CO and N2, N2, CO2, and H2O are retained, CO is simplified as N2 with equal concentration, and is combined with the original N2 component to be recorded as N2'.

6. The method for rapid prediction of the concentration of fuel gas components in a jet engine according to claim 1, characterized in that: The step of weighting by concentration, resolving the concentration ratio of N2 and CO before simplification that meets the given gas specific heat ratio, and obtaining the final original component concentration, is implemented in the following manner: Assuming that the gas components contain both CO and N2, and after being combined and simplified to CO' or N2', the gas contains only pure CO or pure N2. According to the gas concentration-gas specific heat ratio correlation equation, the limiting γ values ​​of the two cases where the gas components contain only pure CO and only pure N2 after simplification can be obtained, which are denoted as γ1 and γ2 respectively. The given gas specific heat ratio is denoted as γ, which should satisfy: or The original concentration values ​​of components CO and N2 are obtained by the above formula.

7. A rapid prediction device for the concentration of fuel gas components in a jet engine, characterized in that: include: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for quickly predicting the concentration of fuel gas components in a jet engine as claimed in any one of claims 1 to 6.

8. A readable storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the method for quickly predicting the concentration of fuel gas components in a jet engine as claimed in any one of claims 1 to 6 is implemented.

9. A computer program product, characterized in that The computer program product comprises: a computer program, which, when executed, executes the method for rapidly predicting the concentration of fuel gas components in a jet engine according to any one of claims 1 to 6.

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