Cyclic Analysis Method for Overall Performance of Turboshaft Engines

Abstract

The present invention discloses a cyclic analysis method for the overall performance of a turboshaft engine. First, a group of turboshaft engine design parameters are cyclically analyzed; then, multiple groups of turboshaft engine design parameters are obtained by cyclic analysis using the same steps; and then, according to design requirements, a selectable domain of turboshaft engine design parameters is selected from the multiple groups of turboshaft engine design parameters. In the cyclic analysis process, this scheme no longer fixes parameters with strong correlation, component design parameters are mutually correlated, and air system design parameters are mutually correlated with component design parameters and turboshaft engine fixed parameters. The parameter selection is reasonable and convenient for program calculation, avoiding repeated iteration of parameter selection, and the cyclic parameter selection efficiency is high. At the same time, the design requirement that the compressor outlet size and the gas turbine inlet size remain unchanged is integrated into the cyclic parameter selection, so that the improved turboshaft engine has a certain interchangeability with the original engine, which is convenient for upgrading and iteration of the turboshaft engine.

Description

Technical Field

[0001] The present invention relates to the technical field of engine design, and in particular to a cyclic analysis method for the overall performance of a turboshaft engine. Background Art

[0002] This paper proposes a method for selecting cycle parameters for overall engine performance for conventional small and medium-power turboshaft engines, maintaining the compressor outlet and gas turbine inlet dimensions unchanged while also considering the correlation between engine component parameters and air system parameters. Compared to traditional cycle parameter selection methods, this proposed method avoids the subsequent iteration of selecting dimensional parameters and component parameters for overall performance and components / systems, improving R&D efficiency and serving as a solution for the overall performance design of small and medium-power turboshaft engines.

[0003] When conducting research, development and design of turboshaft engines, it is often necessary to conduct a cyclic analysis of the overall performance of the turboshaft engine. The existing turboshaft engine package usually has an air intake device, a compressor, a combustion chamber, a gas turbine, a power turbine and a tail nozzle. The gas turbine and the compressor are connected to the same drive shaft, and the combustion chamber is arranged between the gas turbine and the compressor. The air is continuously sucked into the compressor through the air intake device, and after compression, it enters the combustion chamber and burns with the injected fuel to become high-temperature combustion gas, and then enters the gas turbine to expand and perform work. At this time, the expansion work is transmitted to the compressor through the drive shaft to realize continuous operation of the engine, and the gas at the outlet of the gas turbine drives the power turbine to continue to expand and perform work to drive other equipment to work, such as helicopter rotors, generators, etc. The gas at the outlet of the power turbine is discharged into the atmosphere through the tail nozzle.

[0004] At present, the existing turboshaft engine cycle analysis method is: 1) Given the total pressure loss coefficient σ of the intake device i , Compressor inlet conversion flow Wa cor , compressor compression efficiency η c , total pressure loss in the combustion chamber σ b , gas turbine expansion efficiency η t , power turbine expansion efficiency η p , total static pressure ratio of tail nozzle outlet π Nozz and the total pressure loss of some transition sections of the engine (such as the gas turbine / power turbine transition section loss σ t , power turbine / tail nozzle transition section loss σ p ); 2) Given air system parameters, including bleed air volume and distribution ratio; 3) Select different cycle parameters - compressor pressure ratio π c and combustion chamber outlet temperature T t4 , carry out cycle analysis and calculation to obtain the unit power and fuel consumption parameters of the turboshaft engine and the inlet and outlet section parameters of each component.

[0005] However, existing turboshaft engine cycle analysis methods use fixed values ​​for compressor compression efficiency, gas turbine expansion efficiency, and power turbine expansion efficiency. Since compressor compression efficiency is strongly correlated with the compressor inlet converted flow rate and pressure ratio, turbine expansion efficiency is strongly correlated with the turbine expansion ratio and inlet converted flow rate, and the air system's bleed air volume and distribution ratio are strongly correlated with compressor bleed air temperature and turbine flow path temperature parameters, manual adjustments must be made during the design process based on cycle parameters and flow path parameters, making the cycle parameter selection process inefficient. Furthermore, existing cycle analysis methods fail to account for critical dimensional constraints, requiring confirmation of compliance after the initial design of the component is complete, which carries the risk of repeated iterations against design requirements. Summary of the Invention

[0006] The present invention provides a cyclic analysis method for the overall performance of a turboshaft engine, so as to solve the technical problems of low efficiency in selecting cyclic parameters and repeated iteration of parameter selection in existing cyclic analysis methods for turboshaft engines.

[0007] According to one aspect of the present invention, a cyclic analysis method for the overall performance of a turboshaft engine is provided, which is used to perform a cyclic analysis on the overall performance of the turboshaft engine to obtain corresponding design parameters. The turboshaft engine includes an intake device, a compressor, a combustion chamber, a gas turbine, a power turbine, a tail nozzle and an air system, and includes the following steps: S1, obtaining the design parameters of the intake device according to the fixed parameters of the turboshaft engine; S2, presetting the design parameters of the air system by keeping the compressor outlet size unchanged, and selecting the compressor outlet conversion flow deviation, the compressor pressure ratio and the total temperature of the combustion chamber outlet, and then obtaining the compressor design parameters, the combustion chamber design parameters, the gas turbine design parameters, the power turbine design parameters, the tail nozzle design parameters, the turboshaft design parameters and the turboshaft design parameters in sequence according to the fixed parameters of the turboshaft engine and the intake device design parameters. Engine unit power, turboshaft engine fuel consumption rate and updated air system design parameters; S3, select a set of compressor outlet converted flow deviation, compressor pressure ratio and combustion chamber outlet total temperature, substitute them into step S2, until the updated air system parameters are consistent with the preset air system parameters, that is, obtain a set of turboshaft engine design parameters; S4, select multiple sets of compressor outlet converted flow deviation, compressor pressure ratio and combustion chamber outlet total temperature, substitute them into step S3 to obtain multiple sets of turboshaft engine design parameters; S5, by keeping the gas turbine inlet size unchanged, so as to select the turboshaft engine design parameter selectable domain from the multiple sets of turboshaft engine design parameters when the gas turbine inlet converted flow deviation, the turboshaft engine minimum unit power and the turboshaft engine maximum fuel consumption rate meet the design requirements. As a further improvement of the above technical solution:

[0008] Furthermore, the fixed parameters of the turboshaft engine include the total temperature of the turboshaft engine, the total pressure of the turboshaft engine, the total pressure loss coefficient of the air intake device, the total pressure loss of the combustion chamber, the gas turbine / power turbine transition section loss, the power turbine / tail nozzle transition section loss, the total static pressure ratio at the tail nozzle outlet, the static pressure at the tail nozzle outlet, the material selection of the power turbine, the material selection of the gas turbine, the commonly used cooling efficiency coefficient of the turbine blades on the power turbine, and the commonly used cooling efficiency coefficient of the turbine blades on the gas turbine.

[0009] Furthermore, step S1 specifically includes the following steps: obtaining the intake device outlet section parameters according to the total temperature of the turboshaft engine, the total pressure of the turboshaft engine and the total pressure loss coefficient of the intake device, wherein the intake device outlet section parameters include the intake device outlet section total temperature, the intake device outlet section total pressure and the intake device outlet section specific heat ratio.

[0010] Furthermore, in step S2, the compressor design parameters are obtained, which specifically includes the following steps: S211, through data statistics and regression analysis, the functional relationship between the compressor design parameters is obtained: 1) η c,p =f1(Wa c,o ), where f1 is the function relationship obtained through data statistics, Wa c,o is the converted flow rate at the compressor outlet, η c,p is the variable efficiency of the compressor, and the specific function expression is: 2) 3) Where k is the specific heat ratio of the intake device outlet section, Wa cor is the converted import flow, η c is the compressor compression efficiency, π c is the compressor pressure ratio; S212, by keeping the compressor outlet size unchanged, the functional relationship expression is obtained: 4) Wa c,o =(1.0+δ′)Wa c,o,opj , among which, Wa c,o,opj is the reference compressor outlet converted flow rate, δ′ is the compressor outlet converted flow rate deviation, and the value range of δ′ is ±5%; S213, select the reference compressor outlet converted flow rate, the compressor outlet converted flow rate deviation and the compressor pressure ratio to determine the compressor inlet converted flow rate and the compressor compression efficiency according to expressions 1), 2), 3) and 4), and then use the compressor design parameter calculation method to obtain the compressor power consumption and compressor outlet cross-sectional parameters.

[0011] Furthermore, in step S2, the combustion chamber design parameters are obtained, which specifically includes the following steps: presetting the air system design parameters and selecting the total temperature at the combustion chamber outlet, and then using the combustion chamber design parameter calculation method to obtain the combustion chamber fuel flow and the combustion chamber outlet cross-sectional parameters based on the combustion chamber total pressure loss, the combustion chamber outlet total temperature, the compressor outlet cross-sectional parameters and the preset air system design parameters.

[0012] Furthermore, in step S2, the gas turbine design parameters are obtained, which specifically includes the following steps: S221, through data statistics and regression analysis, the functional relationship between the gas turbine design parameters is obtained: 5) η t =f2(Wa cor,th ,π t ), where f2 is the function relationship obtained through data statistics, Wa cor,th is the gas turbine inlet converted flow rate, π t is the gas turbine expansion ratio; S222, based on the combustion chamber outlet section parameters and the preset air system design parameters, a gas turbine design parameter calculation method is used to obtain the gas turbine inlet section parameters, the gas turbine inlet section parameters including the gas turbine inlet converted flow rate, the gas turbine inlet flow rate, the gas turbine inlet section total temperature, the gas turbine inlet specific heat ratio, and the gas turbine inlet specific heat capacity; S223, by maintaining a balance between the compressor power consumption and the gas turbine power, a functional relationship is obtained: 6) Among them, L c is the compressor power consumption, Wa th is the gas turbine inlet flow rate, Cp t is the specific heat capacity of the gas turbine inlet, T t4a is the total temperature of the gas turbine inlet section, η t is the gas turbine expansion efficiency, k t is the gas turbine inlet specific heat ratio; S224, according to expressions 5) and 6), obtain the gas turbine expansion efficiency and gas turbine expansion ratio, and then use the gas turbine design parameter calculation method to obtain the gas turbine outlet cross-sectional parameters.

[0013] Furthermore, in step S2, the power turbine design parameters are obtained, which specifically includes the following steps: S231, through data statistics and regression analysis, the functional relationship between the power turbine design parameters is obtained: 7) η p =f3(Wa cor,p ,π p ), where f3 is the functional relationship of data statistics, Wa cor,p is the converted flow rate at the power turbine inlet, π pis the power turbine expansion ratio; S232, according to the gas turbine outlet cross-sectional parameters, the preset air system design parameters and the gas turbine / power turbine transition section loss, the power turbine design parameter calculation method is used to obtain the power turbine inlet cross-sectional parameters, the power turbine inlet cross-sectional parameters including the power turbine inlet converted flow rate and the power turbine inlet cross-sectional total pressure; S233, by maintaining the balance between the compressor power consumption and the power turbine power, the functional relationship is obtained: 8)π p =P t45 / P0 / π Nozz / (1-σ p ), where P t45 is the total pressure at the power turbine inlet section, σ p is the power turbine / tail nozzle transition section loss, P0 is the tail nozzle outlet static pressure, π Nozz is the total static pressure ratio at the tail nozzle outlet; S234, according to expressions 7) and 8), obtain the power turbine expansion efficiency and the power turbine expansion ratio, and then use the power turbine design parameter calculation method to obtain the power turbine output power and the power turbine outlet cross-sectional parameters.

[0014] Furthermore, in step S2, the tail nozzle design parameters are obtained, which specifically include the following steps: according to the power turbine outlet cross-sectional parameters and the power turbine / tail nozzle transition section loss, the tail nozzle inlet cross-sectional parameters are obtained; and then according to the tail nozzle outlet static pressure, the tail nozzle outlet cross-sectional parameters are obtained using the tail nozzle design parameter calculation method.

[0015] Furthermore, in step S2, updated air system design parameters are obtained, which specifically includes the following steps: based on the air intake device outlet cross-sectional parameters, the compressor outlet cross-sectional parameters, the combustion chamber outlet cross-sectional parameters, the gas turbine inlet cross-sectional parameters, the gas turbine outlet cross-sectional parameters, the power turbine inlet cross-sectional parameters, the power turbine outlet cross-sectional parameters, the tail nozzle inlet cross-sectional parameters, the tail nozzle outlet cross-sectional parameters, the power turbine material selection, the gas turbine material selection, the commonly used cooling efficiency coefficient of the turbine blades on the power turbine, and the commonly used cooling efficiency coefficient of the turbine blades on the gas turbine, the updated air system design parameters are obtained using the air system design parameter calculation method.

[0016] Furthermore, step S5 specifically includes the following steps: S501, by keeping the gas turbine inlet size unchanged, obtain the functional relationship expression: 9) Wa cor,th =(1.0+δ″)Wa cor,th,obj , among which, Wa cor,th is the gas turbine inlet converted flow rate, Wa cor,th,objThe reference gas turbine inlet converted flow rate, δ″, is the gas turbine inlet converted flow rate deviation, and the value range of δ″ is ±5%. S502, when the gas turbine inlet converted flow rate deviation, the minimum unit power of the turboshaft engine, and the maximum fuel consumption rate of the turboshaft engine meet the design requirements, select a turboshaft engine design parameter selectable domain from multiple sets of turboshaft engine design parameters.

[0017] The present invention has the following beneficial effects:

[0018] The cyclic analysis method of the overall performance of the turboshaft engine of the present invention, based on the knowledge of the fixed parameters of the turboshaft engine, selects the compressor outlet converted flow deviation and the compressor pressure ratio by keeping the compressor outlet size unchanged as a constraint, and then presets the air system design parameters and selects the combustion chamber outlet total temperature to obtain the intake device design parameters, compressor design parameters, combustion chamber design parameters, gas turbine design parameters, power turbine design parameters and tail nozzle design parameters in sequence; according to the above parameters, the turboshaft engine unit power and turboshaft engine fuel consumption rate are obtained, and the updated air system design parameters are further obtained; by selecting a group of compressor outlet converted flow deviation, compressor pressure ratio and combustion chamber outlet total temperature and substituting them into the above steps for cyclic analysis, a group of turboshaft engine design parameters is obtained when the updated air system parameters are consistent with the preset air system parameters; and then by selecting multiple groups of compressor outlet converted flow deviation, compressor pressure ratio and combustion chamber outlet Total temperature, obtain multiple sets of turboshaft engine design parameters, and finally, by keeping the gas turbine inlet size unchanged as a constraint, under the condition that the gas turbine inlet converted flow deviation, the turboshaft engine minimum unit power and the turboshaft engine maximum fuel consumption rate meet the design requirements, select the turboshaft engine design parameter selectable domain from the multiple sets of turboshaft engine design parameters to complete the cyclic analysis of the overall performance of the turboshaft engine; in the cyclic analysis process of this scheme, the parameters with strong correlation are not fixed and are interrelated, the component design parameters are interrelated, the air system design parameters and the component design parameters and the turboshaft engine fixed parameters are interrelated, the parameter selection is reasonable and convenient for program calculation, avoiding repeated iteration of parameter selection, and the cyclic parameter selection efficiency is high. At the same time, the design requirement of keeping the compressor outlet size and the gas turbine inlet size unchanged is integrated into the cyclic parameter selection, so that the improved turboshaft engine has a certain interchangeability with the original engine, which is convenient for the upgrade and iteration of the turboshaft engine.

[0019] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a flowchart of a cyclic analysis method for the overall performance of a turboshaft engine according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0022] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0023] Figure 1 It is a flowchart of a cyclic analysis method for the overall performance of a turboshaft engine according to a preferred embodiment of the present invention.

[0024] like Figure 1As shown, the cyclic analysis method of the overall performance of the turboshaft engine of this embodiment is used to perform cyclic analysis on the overall performance of the turboshaft engine to obtain corresponding design parameters. The turboshaft engine includes an intake device, a compressor, a combustion chamber, a gas turbine, a power turbine, a tail nozzle and an air system, and includes the following steps: S1, obtaining the design parameters of the intake device according to the fixed parameters of the turboshaft engine; S2, by keeping the compressor outlet size unchanged, presetting the air system design parameters, and selecting the compressor outlet conversion flow deviation, the compressor pressure ratio and the total temperature of the combustion chamber outlet, and then, according to the fixed parameters of the turboshaft engine and the design parameters of the intake device, sequentially obtaining the compressor design parameters, the combustion chamber design parameters, the gas turbine design parameters, the power turbine design parameters, the tail nozzle design parameters, the turboshaft engine ... Unit power, turboshaft engine fuel consumption rate and updated air system design parameters; S3, select a set of compressor outlet converted flow deviation, compressor pressure ratio and combustion chamber outlet total temperature, substitute them into step S2, until the updated air system parameters are consistent with the preset air system parameters, that is, obtain a set of turboshaft engine design parameters; S4, select multiple sets of compressor outlet converted flow deviation, compressor pressure ratio and combustion chamber outlet total temperature, substitute them into step S3, to obtain multiple sets of turboshaft engine design parameters; S5, by keeping the gas turbine inlet size unchanged, so as to select the turboshaft engine design parameter selectable domain from the multiple sets of turboshaft engine design parameters when the gas turbine inlet converted flow deviation, the turboshaft engine minimum unit power and the turboshaft engine maximum fuel consumption rate meet the design requirements.Specifically, the cyclic analysis method of the overall performance of the turboshaft engine of the present invention, based on the knowledge of the fixed parameters of the turboshaft engine, selects the compressor outlet converted flow deviation and the compressor pressure ratio by keeping the compressor outlet size unchanged as a constraint, and then presets the air system design parameters and selects the combustion chamber outlet total temperature to obtain the intake device design parameters, compressor design parameters, combustion chamber design parameters, gas turbine design parameters, power turbine design parameters and tail nozzle design parameters in sequence; according to the above parameters, the turboshaft engine unit power and turboshaft engine fuel consumption rate are obtained, and the updated air system design parameters are further obtained; by selecting a group of compressor outlet converted flow deviation, compressor pressure ratio and combustion chamber outlet total temperature and substituting them into the above steps for cyclic analysis, a group of turboshaft engine design parameters is obtained when the updated air system parameters are consistent with the preset air system parameters; and then by selecting multiple groups of compressor outlet converted flow deviation, compressor pressure ratio and combustion chamber outlet total temperature, a group of turboshaft engine design parameters is obtained. The total outlet temperature is obtained, and multiple sets of turboshaft engine design parameters are obtained. Finally, by keeping the gas turbine inlet size unchanged as a constraint, the turboshaft engine design parameter selectable domain is selected from the multiple sets of turboshaft engine design parameters under the condition that the gas turbine inlet converted flow deviation, the turboshaft engine minimum unit power and the turboshaft engine maximum fuel consumption rate meet the design requirements, and the cyclic analysis of the overall performance of the turboshaft engine is completed. In the cyclic analysis process of this scheme, the parameters with strong correlation are not fixed and are interrelated, the component design parameters are interrelated, the air system design parameters and the component design parameters are interrelated with the turboshaft engine fixed parameters. The parameter selection is reasonable and convenient for program calculation, which avoids repeated iteration of parameter selection and has high efficiency in cyclic parameter selection. At the same time, the design requirement of keeping the compressor outlet size and the gas turbine inlet size unchanged is integrated into the cyclic parameter selection, so that the improved turboshaft engine has a certain interchangeability with the original engine, which is convenient for the upgrade and iteration of the turboshaft engine.

[0025] In this embodiment, the fixed parameters of the turboshaft engine include the turboshaft engine total temperature, the turboshaft engine total pressure, the intake system total pressure loss coefficient, the combustion chamber total pressure loss, the gas turbine / power turbine transition zone loss, the power turbine / tail nozzle transition zone loss, the tail nozzle outlet total pressure, the tail nozzle outlet static pressure, the power turbine material selection, the gas turbine material selection, the common cooling efficiency coefficient of the turbine blades on the power turbine, and the common cooling efficiency coefficient of the turbine blades on the gas turbine. It should be understood that the tail nozzle outlet static pressure is equal to the atmospheric static pressure.

[0026] In this embodiment, step S1 specifically includes the following steps: obtaining intake device outlet cross-sectional parameters based on the turboshaft engine total temperature, the turboshaft engine total pressure, and the intake device total pressure loss coefficient, wherein the intake device outlet cross-sectional parameters include the intake device outlet cross-sectional total temperature, the intake device outlet cross-sectional total pressure, and the intake device outlet cross-sectional specific heat ratio. It should be understood that the intake device design parameters include the intake device outlet cross-sectional parameters.

[0027] In this embodiment, in step S2, the compressor design parameters are obtained, which specifically includes the following steps: S211, through data statistics and regression analysis, the functional relationship between the compressor design parameters is obtained: 1) η c,p =f1(Wa c,o ), where f1 is the function relationship obtained through data statistics, Wa c,o is the converted flow rate at the compressor outlet, η c,p is the variable efficiency of the compressor, and the specific function expression is: 2) 3) Where k is the specific heat ratio of the intake device outlet section, Wa cor is the converted import flow, η c is the compressor compression efficiency, π c is the compressor pressure ratio; S212, by keeping the compressor outlet size unchanged, the functional relationship expression is obtained: 4) Wa c,o =(1.0+δ′)Wa c,o,opj , among which, Wa c,o,opj The reference compressor outlet converted flow rate, δ′, and the compressor outlet converted flow rate deviation are within a range of ±5%. In step S213, the reference compressor outlet converted flow rate, the compressor outlet converted flow rate deviation, and the compressor pressure ratio are selected to determine the compressor inlet converted flow rate and compressor compression efficiency according to expressions 1), 2), 3), and 4). The compressor design parameter calculation method is then used to obtain the compressor power consumption and compressor outlet cross-sectional parameters. Specifically, by correlating the compressor compression efficiency with other compressor parameters, the selection of compressor design parameters is rational and facilitates program calculation. Specifically, the constant compressor outlet dimension is incorporated into the compressor design parameter calculation. It should be understood that the compressor design parameters include the compressor inlet converted flow rate, compressor compression efficiency, compressor power consumption, and compressor outlet cross-sectional parameters. It should be understood that the specific steps of the compressor design parameter calculation method are well known to those skilled in the art. For details, reference can be made to the "Principles of Aeroengines" published by Northwestern Polytechnical University. It should be understood that the intake device outlet is directly connected to the compressor inlet, and the intake device outlet cross-sectional specific heat ratio is equivalent to the compressor inlet cross-sectional specific heat ratio, which can be used in Expression 2) and Expression 3).

[0028] In this embodiment, in step S2, the combustion chamber design parameters are obtained, specifically including the following steps: presetting the air system design parameters and selecting the total temperature at the combustion chamber outlet; then, based on the combustion chamber total pressure loss, the total temperature at the combustion chamber outlet, the compressor outlet cross-sectional parameters, and the pre-set air system design parameters, using a combustion chamber design parameter calculation method to obtain the combustion chamber fuel flow rate and combustion chamber outlet cross-sectional parameters. It should be understood that the combustion chamber design parameters include the combustion chamber fuel flow rate and the combustion chamber outlet cross-sectional parameters. It should be understood that the specific steps of the combustion chamber design parameter calculation method are well known to those skilled in the art, and reference can be made to the "Principles of Aeroengines" published by Northwestern Polytechnical University for details.

[0029] In this embodiment, in step S2, the gas turbine design parameters are obtained, which specifically includes the following steps: S221, through data statistics and regression analysis, the functional relationship between the gas turbine design parameters is obtained: 5) η t =f2(Wa cor,th ,π t ), where f2 is the function relationship obtained through data statistics, Wa cor,th is the gas turbine inlet converted flow rate, π t is the gas turbine expansion ratio; S222, based on the combustion chamber outlet section parameters and the preset air system design parameters, a gas turbine design parameter calculation method is used to obtain the gas turbine inlet section parameters, the gas turbine inlet section parameters including the gas turbine inlet converted flow rate, the gas turbine inlet flow rate, the gas turbine inlet section total temperature, the gas turbine inlet specific heat ratio, and the gas turbine inlet specific heat capacity; S223, by maintaining a balance between the compressor power consumption and the gas turbine power, a functional relationship is obtained: 6) Among them, L c is the compressor power consumption, Wa th is the gas turbine inlet flow rate, Cp t is the specific heat capacity of the gas turbine inlet, T t4a is the total temperature of the gas turbine inlet section, η t is the gas turbine expansion efficiency, k t is the gas turbine inlet specific heat ratio; S224, according to expressions 5) and 6), the gas turbine expansion efficiency and the gas turbine expansion ratio are obtained, and then the gas turbine outlet cross-sectional parameters are obtained by using the gas turbine design parameter calculation method. Specifically, by associating the gas turbine expansion efficiency with other parameters of the gas turbine, the selection of gas parameter design parameters is reasonable and conducive to program calculation. It should be understood that the gas turbine design parameters include the gas turbine inlet cross-sectional parameters, the gas turbine expansion efficiency, the gas turbine expansion ratio and the gas turbine outlet cross-sectional parameters. It should be understood that the gas turbine design parameter calculation method is a well-known technology for those skilled in the art, and specific reference can be made to the "Principles of Aeroengines" published by Northwestern Polytechnical University.

[0030] In this embodiment, in step S2, the power turbine design parameters are obtained, which specifically includes the following steps: S231, through data statistics and regression analysis, the functional relationship between the power turbine design parameters is obtained: 7) η p =f3(Wa cor,p ,π p ), where f3 is the functional relationship of data statistics, Wa cor,p is the converted flow rate at the power turbine inlet, π p is the power turbine expansion ratio; S232, according to the gas turbine outlet cross-sectional parameters, the preset air system design parameters and the gas turbine / power turbine transition section loss, the power turbine design parameter calculation method is used to obtain the power turbine inlet cross-sectional parameters, the power turbine inlet cross-sectional parameters including the power turbine inlet converted flow rate and the power turbine inlet cross-sectional total pressure; S233, by maintaining the balance between the compressor power consumption and the power turbine power, the functional relationship is obtained: 8)π p =P t45 / P0 / π Nozz / (1-σ p ), where P t45 is the total pressure at the power turbine inlet section, σ p is the power turbine / tail nozzle transition section loss, P0 is the tail nozzle outlet static pressure, π Nozz is the total static pressure ratio at the tail nozzle outlet; S234, according to expressions 7) and 8), the power turbine expansion efficiency and the power turbine expansion ratio are obtained, and then the power turbine design parameter calculation method is used to obtain the power turbine output power and the power turbine outlet cross-sectional parameters. Specifically, by associating the power turbine expansion efficiency with other parameters of the power turbine, the selection of the power turbine design parameters is reasonable and conducive to program calculation. It should be understood that the power turbine design parameters include the power turbine inlet cross-sectional parameters, the power turbine expansion efficiency, the power turbine expansion ratio, the power turbine output power and the power turbine outlet cross-sectional parameters. It should be understood that the power turbine design parameter calculation method is a well-known technology for those skilled in the art, and specific reference may be made to the "Principles of Aeroengines" published by Northwestern Polytechnical University.

[0031] In this embodiment, in step S2, the tail nozzle design parameters are obtained, specifically including the following steps: obtaining the tail nozzle inlet cross-sectional parameters based on the power turbine outlet cross-sectional parameters and the power turbine / tail nozzle transition section losses; then, obtaining the tail nozzle outlet cross-sectional parameters using a tail nozzle design parameter calculation method based on the tail nozzle outlet static pressure. It should be understood that the tail nozzle design parameters include the tail nozzle inlet cross-sectional parameters and the tail nozzle outlet cross-sectional parameters. It should be understood that the tail nozzle design parameter calculation method is well known to those skilled in the art, and specific reference can be made to the "Principles of Aeroengines," published by Northwestern Polytechnical University.

[0032] In this embodiment, in step S2, obtaining updated air system design parameters specifically includes the following steps: obtaining updated air system design parameters using an air system design parameter calculation method based on the air intake device outlet cross-sectional parameters, the compressor outlet cross-sectional parameters, the combustor outlet cross-sectional parameters, the gas turbine inlet cross-sectional parameters, the gas turbine outlet cross-sectional parameters, the power turbine inlet cross-sectional parameters, the power turbine outlet cross-sectional parameters, the tailpipe inlet cross-sectional parameters, the tailpipe outlet cross-sectional parameters, the power turbine material selection, the gas turbine material selection, the common cooling efficiency coefficients of turbine blades on the power turbine, and the common cooling efficiency coefficients of turbine blades on the gas turbine. It should be understood that the air intake device outlet cross-sectional parameters include the total temperature of the air intake device outlet cross-sectional parameters. It should be understood that the compressor outlet cross-sectional parameters include the total temperature of the compressor outlet cross-sectional parameters. It should be understood that the combustor outlet cross-sectional parameters include the total temperature of the combustor outlet cross-sectional parameters. It should be understood that the gas turbine inlet cross-sectional parameters include the total temperature of the gas turbine inlet cross-sectional parameters. It should be understood that the gas turbine outlet cross-sectional parameters include the total temperature of the gas turbine outlet cross-sectional parameters. It should be understood that the power turbine inlet cross-sectional parameters include the total temperature of the power turbine inlet cross-sectional parameters. It should be understood that the power turbine outlet cross-sectional parameters include the total temperature of the power turbine outlet cross-sectional parameters. It should be understood that the tail nozzle inlet cross-sectional parameters include the total temperature of the tail nozzle inlet cross-sectional parameters. It should be understood that the tail nozzle outlet cross-sectional parameters include the total temperature of the tail nozzle outlet cross-sectional parameters. Specifically, by correlating the air system design parameters with the total temperature of the intake device outlet cross-sectional parameters, the total temperature of the compressor outlet cross-sectional parameters, the total temperature of the combustor outlet cross-sectional parameters, the total temperature of the gas turbine inlet cross-sectional parameters, the total temperature of the gas turbine outlet cross-sectional parameters, the total temperature of the power turbine inlet cross-sectional parameters, the total temperature of the power turbine outlet cross-sectional parameters, the total temperature of the tail nozzle inlet cross-sectional parameters, the total temperature of the tail nozzle outlet cross-sectional parameters, the gas turbine material selection, the commonly used cooling efficiency coefficients of turbine blades on the power turbine, and the commonly used cooling efficiency coefficients of turbine blades on the gas turbine, the selection of air system design parameters is reasonable and facilitates program calculation. It should be understood that the compressor outlet is a commonly used bleed air location. It should be understood that the calculation method of air system design parameters is well known to those skilled in the art. For details, reference can be made to the "Principles of Aeroengines" published by Northwestern Polytechnical University.

[0033] In this embodiment, step S5 specifically includes the following steps: S501, by keeping the gas turbine inlet size unchanged, obtain the functional relationship expression: 9) Wa cor,th =(1.0+δ″)Wa cor,th,obj , among which, Wa cor,th is the gas turbine inlet converted flow rate, Wa cor,th,objThe reference gas turbine inlet converted flow rate, δ″, is the gas turbine inlet converted flow rate deviation, and the value range of δ″ is ±5%. S502, when the gas turbine inlet converted flow rate deviation, the minimum unit power of the turboshaft engine, and the maximum fuel consumption rate of the turboshaft engine meet the design requirements, select a turboshaft engine design parameter selectable domain from multiple sets of turboshaft engine design parameters.

[0034] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for cyclically analyzing the overall performance of a turboshaft engine, for cyclically analyzing the overall performance of the turboshaft engine to obtain corresponding design parameters. The turboshaft engine includes an air intake device, a compressor, a combustion chamber, a gas turbine, a power turbine, a tail nozzle, and an air system, and is characterized in that: The following steps are involved: S1, obtaining the design parameters of the air intake device according to the fixed parameters of the turboshaft engine; S2, by keeping the compressor outlet size unchanged, presetting the air system design parameters, and selecting the compressor outlet converted flow deviation, compressor pressure ratio, and combustor outlet total temperature, then according to the turboshaft engine fixed parameters and the intake device design parameters, sequentially obtain the compressor design parameters, combustor design parameters, gas turbine design parameters, power turbine design parameters, tail nozzle design parameters, turboshaft engine unit power, turboshaft engine fuel consumption rate, and updated air system design parameters; S3, selecting a set of compressor outlet converted flow deviation, compressor pressure ratio, and combustor outlet total temperature, and substituting them into step S2 until the updated air system parameters are consistent with the preset air system parameters, thereby obtaining a set of turboshaft engine design parameters; S4, selecting multiple sets of compressor outlet converted flow deviations, compressor pressure ratios, and combustion chamber outlet total temperatures, and substituting them into step S3 to obtain multiple sets of turboshaft engine design parameters; S5, by keeping the gas turbine inlet size unchanged, a selectable domain of turboshaft engine design parameters is selected from multiple sets of turboshaft engine design parameters under the condition that the gas turbine inlet converted flow deviation, the minimum unit power of the turboshaft engine, and the maximum fuel consumption rate of the turboshaft engine meet the design requirements.

2. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 1, characterized in that: The fixed parameters of the turboshaft engine include the total temperature of the turboshaft engine, the total pressure of the turboshaft engine, the total pressure loss coefficient of the air intake device, the total pressure loss of the combustion chamber, the gas turbine / power turbine transition section loss, the power turbine / tail nozzle transition section loss, the total static pressure ratio of the tail nozzle outlet, the static pressure of the tail nozzle outlet, the material selection of the power turbine, the material selection of the gas turbine, the commonly used cooling efficiency coefficient of the turbine blades on the power turbine, and the commonly used cooling efficiency coefficient of the turbine blades on the gas turbine.

3. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 2, characterized in that: Step S1 specifically The following steps are included: The intake device outlet section parameters are obtained based on the total temperature of the turboshaft engine, the total pressure of the turboshaft engine, and the total pressure loss coefficient of the intake device, wherein the intake device outlet section parameters include the total temperature of the intake device outlet section, the total pressure of the intake device outlet section, and the specific heat ratio of the intake device outlet section.

4. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 3, characterized in that: In step S2, the compressor design parameters are obtained, which specifically includes the following steps: S211, through data statistics and regression analysis, obtain the functional relationship between compressor design parameters: 1) η c,p =f1(Wa c,o ), where f1 is the function relationship obtained through data statistics, Wa c,o is the converted flow rate at the compressor outlet, η c,p is the variable efficiency of the compressor, and the specific function expression is: 2) 3) Where k is the specific heat ratio of the intake device outlet section, Wa cor is the converted import flow, η c is the compressor compression efficiency, π c is the compressor pressure ratio; S212, by keeping the compressor outlet size unchanged, the functional relationship expression is obtained: 4) Wa c,o =(1.0+δ′)Wa c,o,opj , among which, Wa c,o,opj is the reference compressor outlet converted flow rate, δ′ is the compressor outlet converted flow rate deviation, and the value range of δ′ is ±5%; S213, select the reference compressor outlet converted flow rate, the compressor outlet converted flow rate deviation and the compressor pressure ratio to determine the compressor inlet converted flow rate and the compressor compression efficiency according to expressions 1), 2), 3) and 4), and then use the compressor design parameter calculation method to obtain the compressor power consumption and compressor outlet cross-sectional parameters.

5. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 4, characterized in that: In step S2, the combustion chamber design parameters are obtained, which specifically includes the following steps: The air system design parameters are preset, and the total temperature at the combustion chamber outlet is selected. Then, based on the total pressure loss of the combustion chamber, the total temperature at the combustion chamber outlet, the compressor outlet cross-sectional parameters and the preset air system design parameters, the combustion chamber design parameter calculation method is used to obtain the combustion chamber fuel flow rate and the combustion chamber outlet cross-sectional parameters.

6. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 5, characterized in that: In step S2, the gas turbine design parameters are obtained, which specifically includes the following steps: S221, through data statistics and regression analysis, obtain the functional relationship between gas turbine design parameters: 5) η t =f2(Wa cor,th ,π t ), where f2 is the function relationship obtained through data statistics, Wa cor,th is the gas turbine inlet converted flow rate, π t is the gas turbine expansion ratio; S222, obtaining gas turbine inlet cross-sectional parameters using a gas turbine design parameter calculation method based on the combustion chamber outlet cross-sectional parameters and the preset air system design parameters, the gas turbine inlet cross-sectional parameters including the gas turbine inlet converted flow rate, the gas turbine inlet flow rate, the gas turbine inlet cross-sectional total temperature, the gas turbine inlet specific heat ratio, and the gas turbine inlet specific heat capacity; S223, by maintaining the balance between compressor power consumption and gas turbine power, the functional relationship is obtained: 6) Among them, L c is the compressor power consumption, Wa th is the gas turbine inlet flow rate, Cp t is the specific heat capacity of the gas turbine inlet, T t4a is the total temperature of the gas turbine inlet section, η t is the gas turbine expansion efficiency, k t is the gas turbine inlet specific heat ratio; S224, according to expressions 5) and 6), the gas turbine expansion efficiency and the gas turbine expansion ratio are obtained, and then the gas turbine design parameter calculation method is used to obtain the gas turbine outlet cross-sectional parameters.

7. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 6, characterized in that: In step S2, the power turbine design parameters are obtained, which specifically includes the following steps: S231, through data statistics and regression analysis, obtain the functional relationship between the power turbine design parameters: 7) η p =f3(Wa cor,p ,π p ), where f3 is the functional relationship of data statistics, Wa cor,p is the converted flow rate at the power turbine inlet, π p is the power turbine expansion ratio; S232, based on the gas turbine outlet cross-sectional parameters, the preset air system design parameters, and the gas turbine / power turbine transition section losses, a power turbine design parameter calculation method is used to obtain the power turbine inlet cross-sectional parameters, where the power turbine inlet cross-sectional parameters include the power turbine inlet converted flow rate and the power turbine inlet cross-sectional total pressure; S233, by maintaining the balance between compressor power consumption and power turbine power, the functional relationship is obtained: 8)π p =P t45 / P0 / π Nozz / (1-σ p ), where P t45 is the total pressure at the power turbine inlet section, σ p is the power turbine / tail nozzle transition section loss, P0 is the tail nozzle outlet static pressure, π Nozz is the total static pressure ratio at the tail nozzle outlet; S234, according to expressions 7) and 8), the power turbine expansion efficiency and the power turbine expansion ratio are obtained, and then the power turbine design parameter calculation method is used to obtain the power turbine output power and the power turbine outlet cross-sectional parameters.

8. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 7, characterized in that: In step S2, the tail nozzle design parameters are obtained, which specifically includes the following steps: The tail nozzle inlet cross-sectional parameters are obtained according to the power turbine outlet cross-sectional parameters and the power turbine / tail nozzle transition section loss. Then, the tail nozzle outlet cross-sectional parameters are obtained using the tail nozzle design parameter calculation method based on the tail nozzle outlet static pressure.

9. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 8, characterized in that: In step S2, updated air system design parameters are obtained, which specifically includes the following steps: The updated air system design parameters are obtained by using an air system design parameter calculation method based on the air intake device outlet cross-sectional parameters, the compressor outlet cross-sectional parameters, the combustion chamber outlet cross-sectional parameters, the gas turbine inlet cross-sectional parameters, the gas turbine outlet cross-sectional parameters, the power turbine inlet cross-sectional parameters, the power turbine outlet cross-sectional parameters, the tail nozzle inlet cross-sectional parameters, the tail nozzle outlet cross-sectional parameters, the power turbine material selection, the gas turbine material selection, the commonly used cooling efficiency coefficient of the turbine blades on the power turbine, and the commonly used cooling efficiency coefficient of the turbine blades on the gas turbine.

10. The cyclic analysis method for the overall performance of a turboshaft engine according to claim 9, characterized in that: Step S5 specifically includes the following steps: S501, by keeping the gas turbine inlet size unchanged, the functional relationship expression is obtained: 9) Wa cor,th =(1.0+δ″)Wa cor,th,obj , among which, Wa cor,th is the gas turbine inlet converted flow rate, Wa cor,th,obj is the reference gas turbine inlet converted flow rate, δ″ is the gas turbine inlet converted flow rate deviation, and the value range of δ″ is ±5%; S502 , when the gas turbine inlet converted flow deviation, the turboshaft engine minimum unit power, and the turboshaft engine maximum fuel consumption rate meet design requirements, select a turboshaft engine design parameter selectable domain from multiple sets of turboshaft engine design parameters.

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