Engine thermodynamic cycle parameter calculation method based on core engine matching

Abstract

The invention discloses an engine thermodynamic cycle parameter calculation method based on core engine matching, and the method comprises the following steps: carrying out the unified modeling of all parts of a main airflow channel of an engine based on GSP numerical simulation software, and forming a complete machine model group; performing parameter calculation and complete machine performance calculation on each section of the complete machine model group to obtain a core performance index; simulation calculation is executed, and a whole machine working point of the engine is obtained; judging whether the whole machine working point meets the index requirement or not, and if the whole machine working point does not meet the index requirement, executing the simulation calculation again; and if the index requirements are met, the whole machine working point of the engine is output. According to the technical scheme, the initial characteristic parameters of the core engine can be adjusted according to the calculation result, and iterative calculation is repeated to achieve the effect of improving the unit thrust parameter scheme of the engine.

Description

Technical Field

[0001] This invention relates to the field of overall performance of aero engines, and more specifically, to a method for calculating engine thermodynamic cycle parameters based on core engine matching. Background Technology

[0002] In recent years, unmanned aerial vehicle (UAV) technology has developed rapidly. Intelligent swarms of UAVs, characterized by high flexibility, strong system coordination capabilities, and low-cost operations, have quickly entered the vision of military organizations worldwide and frequently appeared in local battlefields. Considering the greater advantages of gas turbine engines in terms of operating envelope, speed and altitude range, maneuverability, propulsion efficiency, and loiter time, they will become the preferred power source for military UAVs and will be the main development direction of power systems for a considerable period of time. Compared with conventional aviation gas turbine engines, to adapt to the special missions of UAV systems and meet their requirements for speed, altitude, range, stealth, maneuverability, reliability, controllability, and long lifespan, UAV power systems should possess significant characteristics such as lower fuel consumption, higher power extraction capability, longer endurance, resistance to high overload, all-around stealth, and low cost.

[0003] To meet the power requirements of domestic unmanned aerial vehicles (UAVs) with high thrust per unit area and low bypass ratio afterburning thrust, this invention conducts research on key technologies for developing low bypass ratio turbofan engines based on engine core engines. Since core engine-derived engines have the advantages of short development cycles and high technological maturity, this invention proposes a method for calculating engine thermodynamic cycle parameters based on core engine matching. This method primarily addresses the problem of iterative and lengthy engine performance calculations, and can be used to meet the needs of rapid serialization development based on mature engines. Summary of the Invention

[0004] To achieve the above objectives, this application provides a method for calculating engine thermodynamic cycle parameters based on core engine matching, comprising the following steps: Based on GSP numerical simulation software, the components of the engine's main airflow channel are modeled in a unified manner to form a complete engine model group. Parameter calculations and overall performance calculations are performed on each section of the complete machine model group to obtain core performance indicators; Perform simulation calculations to obtain the engine's overall operating point; Determine whether the overall engine operating point meets the target requirements. If it does not meet the target requirements, re-execute the simulation calculation; if it meets the target requirements, output the overall engine operating point.

[0005] The complete engine model assembly includes: an intake manifold, a fan, a compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, and an exhaust system; if the engine is a hybrid engine, the complete engine model assembly also includes a mixing chamber.

[0006] Key performance indicators include: engine thrust, fuel consumption rate, airflow, bypass ratio, and turbine inlet temperature.

[0007] Furthermore, before performing simulation calculations, initial characteristic parameters are obtained; When re-executing the simulation calculation, the core machine operating point is adjusted, which includes the high-pressure compressor speed, pressure ratio, flow rate, and efficiency.

[0008] The initial characteristic parameters include the compressor inlet equivalent flow rate, equivalent speed, pressure ratio, and combustion chamber outlet temperature rise ratio of the existing core engine.

[0009] Furthermore, the simulation calculation includes: based on the high-pressure common operating line of the whole machine model group, selecting the high-pressure compressor operating point, matching low-pressure components with different pressure ratios and flow rates, and using flow balance, power balance, and pressure balance calculations to obtain the whole machine operating point of the engine.

[0010] This invention, based on GSP numerical simulation software, uniformly models all components of the engine's main airflow channel to form a complete engine model group. Initial parameters of the core engine are input to complete the simulation calculation. Based on the calculation results, the initial characteristic parameters of the core engine are adjusted, and iterative calculations are repeated to achieve the effect of improving the engine's unit thrust parameter. Compared with existing technologies, this method has the advantages of a short development cycle, high technological maturity, and strong versatility. Attached Figure Description

[0011] Figure 1 This is a flowchart illustrating the steps of an engine thermodynamic cycle parameter calculation method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the GSP numerical calculation model provided in an embodiment of the present invention. Detailed Implementation

[0012] The proposed method for calculating engine thermodynamic cycle parameters based on core engine matching uses the operating point of an existing mature core engine (an engine that has completed model development and is already in use). By rematching low-pressure components, the fan pressure ratio is increased and the bypass ratio is reduced, thereby improving the engine's unit thrust.

[0013] The specific implementation of the present invention will now be described in detail with reference to the accompanying drawings.

[0014] The steps of the engine thermodynamic cycle parameter calculation method based on core engine matching provided by this invention are as follows: Figure 1 As shown, it includes: Step S100: Based on GSP numerical simulation software, perform unified modeling of each component of the engine's main airflow channel to form a complete engine model group; The engine model set specifically includes components such as the intake manifold, fan, compressor, combustion chamber, high-pressure turbine, low-pressure turbine, mixing chamber (applicable to mixed-emission engines), and exhaust system. In this step, the entire machine is modeled in a unified manner to form a complete machine model group, such as... Figure 2 As shown, the model of the whole engine model group includes models of various components of the main airflow channel of the engine. The initial parameters input into the whole engine model group can realize simulation calculation. The whole engine model group includes component models such as: intake duct, fan, compressor, combustion chamber, high-pressure turbine, low-pressure turbine, and exhaust device; if the engine is a hybrid engine, the whole engine model group also includes a mixing chamber.

[0015] Step S110: Based on the whole machine model group, perform performance calculations on parameters such as pressure, temperature, and flow rate of the engine at each cross section along the flow path to obtain core performance indicators; Specifically, core performance indicators include engine thrust, fuel consumption rate, airflow, bypass ratio, and other performance parameters.

[0016] Step S120: Perform simulation calculations to obtain the engine's overall operating point; Before performing simulation calculations, obtain the initial characteristic parameters; Initial characteristic parameters include the compressor inlet converted flow rate, converted speed, pressure ratio, and combustion chamber outlet temperature rise ratio of the existing core engine. Based on mature engines, a common high-pressure operating line for the entire engine model group can be obtained, and the high-pressure compressor operating point on the common operating line can be selected as the engine design point. The parameters of the core engine's thermodynamic cycle design point include: compressor speed, pressure ratio, flow rate, and efficiency; combustion chamber outlet temperature; and high-pressure turbine efficiency.

[0017] During simulation calculations, initial characteristic parameters are input, and the fan pressure ratio and bypass ratio are changed to obtain the engine's overall operating point. The specific calculation process is as follows: Based on a mature engine, the high-pressure common operating line of the entire engine model group is calculated. The high-pressure compressor operating point on the common operating line is selected, and low-pressure components with different pressure ratios and flow rates are matched. The engine's overall operating point is then calculated using flow balance, power balance, and pressure balance. Pressure balance is applicable to mixed exhaust systems.

[0018] Specifically, the overall operating point is the operating point of the compressor and other components. The parameters of the operating point include indicators such as engine speed, pressure ratio, flow rate, and turbine inlet temperature.

[0019] Step S130: Perform iterative optimization to improve engine parameter performance levels; That is: determine whether the overall engine operating point output in step S120 meets the target requirements. If it does not meet the target requirements, re-execute the simulation calculation; if it meets the target requirements, output the overall engine operating point.

[0020] During the evaluation process, the influence of key design variables such as the core engine operating point (represented by the compressor relative conversion speed) and fan boost ratio on characteristic parameters such as engine thrust, fuel consumption rate, and bypass ratio at ground intermediate and maximum states is analyzed and judged to determine whether these influences meet the performance parameter requirements proposed by the aircraft manufacturer or user.

[0021] If the target requirements are not met, the simulation calculation is re-executed, proceeding to step S120. During the re-execution of the simulation calculation, the core operating points of the high-pressure compressor, such as speed, pressure ratio, flow rate, and efficiency, are adjusted, and the low-pressure components are re-matched.

[0022] If the target requirements are met, the engine's overall operating point can be determined. At this point, the engine's performance levels, such as unit thrust and fuel consumption, are optimized through iteration.

[0023] This invention, based on GSP numerical simulation software, uniformly models all components of the engine's main airflow channel to form a complete engine model group, and completes simulation calculations by inputting the initial parameters of the core engine. Based on the calculation results, the initial characteristic parameters of the core engine are adjusted, and iterative calculations are repeated to achieve the effect of improving the engine's unit thrust parameter. Compared with existing technologies, this method has the advantages of short development cycle, high technological maturity, and strong versatility.

[0024] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the present invention is not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A method for calculating engine thermodynamic cycle parameters based on core engine matching, characterized in that, Includes the following steps: Based on GSP numerical simulation software, the components of the engine's main airflow channel are modeled in a unified manner to form a complete engine model group. Parameter calculations and overall performance calculations are performed on each section of the complete machine model group to obtain core performance indicators; Perform simulation calculations to obtain the engine's overall operating point thermodynamic cycle parameters; Determine whether the overall machine operating point meets the target requirements. If it does not meet the target requirements, re-execute the simulation calculation. If the target requirements are met, output the overall operating point thermodynamic cycle parameters of the engine.

2. The method for calculating engine thermodynamic cycle parameters according to claim 1, characterized in that, The complete engine model assembly includes: an intake manifold, a fan, a compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, and an exhaust system; if the engine is a hybrid engine, the complete engine model assembly also includes a mixing chamber.

3. The method for calculating engine thermodynamic cycle parameters according to claim 1, characterized in that, The core performance indicators include: engine thrust, fuel consumption rate, airflow, bypass ratio, and turbine inlet temperature.

4. The method for calculating engine thermodynamic cycle parameters according to claim 1, characterized in that, Before performing the simulation calculation, the initial characteristic parameters are obtained; When re-executing the simulation calculation, the core machine operating point is adjusted. The thermodynamic cycle parameters of the core machine operating point include the high-pressure compressor speed, pressure ratio, flow rate, and efficiency.

5. The method for calculating engine thermodynamic cycle parameters according to claim 4, characterized in that, The initial characteristic parameters include the compressor inlet equivalent flow rate, equivalent speed, pressure ratio, and combustion chamber outlet temperature rise ratio of the existing core engine.

6. The method for calculating engine thermodynamic cycle parameters according to claim 1, characterized in that, The simulation calculation includes: based on the high-pressure common operating line of the whole machine model, selecting the high-pressure compressor operating point, matching low-pressure components with different pressure ratios and flow rates, and using flow balance, power balance, and pressure balance to calculate the thermodynamic cycle parameters of the engine's whole machine operating point.

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