A batch extraction processing method of combustion characteristic parameters

Abstract

The present application provides a batch extraction processing method of combustion characteristic parameters, belongs to the field of internal combustion engine combustion simulation post-processing and thermodynamic process analysis, solves the problems of dispersed simulation file sources, non-uniform crank angle range, incomplete P-V cycle construction, manual recognition of injection parameters and extraction of combustion indicators, low efficiency and inconsistent standards in multi-condition comparison, and easy data error in internal combustion engine simulation post-processing. The present application provides a batch extraction processing method of combustion characteristic parameters, which realizes full-process automatic analysis through data verification, parameter extraction, data preprocessing, thermodynamic index calculation and multi-condition standardized output. The present application replaces manual operation, greatly improves the efficiency and data accuracy of multi-condition simulation post-processing, ensures the uniformity of analysis standards, and provides reliable support for internal combustion engine optimization.

Description

Technical Field

[0001] This invention relates to the field of post-processing and thermodynamic process analysis technology for internal combustion engine combustion simulation, and in particular to a method for batch extraction and processing of combustion characteristic parameters. Background Technology

[0002] In the development of internal combustion engines, 3D CFD simulation has been widely used to analyze in-cylinder spray, mixing, ignition, combustion, heat transfer, and emission generation processes. For the same engine structure or different injection, intake, and combustion chamber shapes, it is usually necessary to establish a large number of simulation conditions and compare and analyze the calculation results of each condition. Existing engine simulation software typically outputs multiple types of result files. For example, engine structural parameters are usually stored in the engine input file, boundary temperature and other information are stored in the boundary condition file, injection timing, nozzle diameter, injection mass, and nozzle spatial position are stored in the spray input file, while thermodynamic results such as cylinder pressure, temperature, density, volume, heat release rate, and cumulative heat release rate are stored in different output files.

[0003] In practical simulation post-processing, existing technologies suffer from the following problems: When developing combustion systems, the industry needs to consider both computational resources and computation time costs. Typically, only the crankshaft angle range for design spray combustion from intake valve closed to exhaust valve open is calculated. When calculating performance parameters such as thermal efficiency, a complete cycle of data encompassing the intake and exhaust processes is required. This process necessitates splitting and merging complete data for the crankshaft angle range under existing operating conditions. When comparing multiple simulation conditions in batches, it requires manually opening files, extracting parameters, calculating indices, plotting curves, and compiling tables one by one. This process is cumbersome and prone to errors due to differences in path hierarchy, file naming, data units, and crankshaft angle ranges. Furthermore, key moments in combustion analysis, such as SOI, EOI, SOC, Pmax, maximum pressure rise rate, CA5, CA10, CA50, and CA90, rely on manual table lookups, plotting, and interpolation, which is not only inefficient but also makes it difficult to maintain consistent processing standards across different calculation cases.

[0004] Therefore, it is necessary to propose a method that can automatically read multiple simulation condition files, unify crankshaft angle reference, fuse multi-source cylinder pressure data, reconstruct the complete PV cycle, and automatically calculate combustion thermodynamic indicators, thereby improving the accuracy, efficiency, and consistency of post-processing of engine simulation results. Summary of the Invention

[0005] This invention provides a batch extraction and processing method for combustion characteristic parameters. By batch identifying simulation condition files, automatically extracting engine, boundary, and injection parameters, unifying crankshaft angle coordinates and adaptively identifying injection timing units, it completes cylinder pressure data completion, instantaneous cylinder volume reconstruction, and complete PV cycle construction. It automatically calculates thermodynamic performance indicators and identifies key combustion moments, ultimately achieving standardized comparison and output of multi-condition results. This addresses the problems in existing internal combustion engine simulation post-processing, such as scattered simulation file sources, inconsistent crankshaft angle ranges, incomplete PV cycle construction, reliance on manual injection parameter identification and combustion indicator extraction, low efficiency and inconsistent standards in multi-condition comparison, and susceptibility to data errors.

[0006] A method for batch extraction and processing of combustion characteristic parameters includes the following steps: S1. Batch acquire one or more internal combustion engine 3D combustion simulation working condition directories and complete the file integrity identification within the working condition directory; S2. Extract the engine basic parameters, boundary parameters, and injection parameters sequentially from the qualified files; S3. Read the thermal output data and unify the crankshaft angle coordinates, while performing unit adaptive recognition of the injection start time; S4. Calculate the compression ratio based on the read volume data, and perform truncation and patching processing on the cylinder pressure data; S5. Reconstruct the instantaneous cylinder volume by combining engine structural parameters, and build a complete thermodynamic cycle based on the completed cylinder pressure data and instantaneous volume data; S6. Calculate the thermodynamic performance indicators of the internal combustion engine based on the complete thermodynamic cycle and identify various key moments in the combustion process; S7. Perform batch comparison of calculation results for multiple simulation conditions and output standardized analysis results.

[0007] Furthermore, in S1, the operating condition catalog includes at least the engine input file, boundary condition file, spray input file, cylinder pressure output file, and thermal output file; In S2, the cylinder bore, stroke, connecting rod length, engine speed, swirl ratio, piston boundary ID, cylinder liner boundary ID, and cylinder head boundary ID are extracted from the engine input file. The displacement is calculated by combining the cylinder bore and stroke, and the average piston speed is calculated by combining the engine speed and stroke. Based on the extracted piston boundary ID, cylinder liner boundary ID, and cylinder head boundary ID, the piston wall temperature, cylinder liner wall temperature, and cylinder head wall temperature are matched and read from the boundary condition file. The injector spatial position, injection start time, injection duration, total injection quantity, nozzle diameter, nozzle position, nozzle radial distance, nozzle axial distance, and spray angle are extracted from the spray input file.

[0008] Furthermore, in S3, the crankshaft angle, pressure, average temperature, density, cumulative heat release rate, heat release rate, and cylinder volume data from the thermodynamic output file are read. The crankshaft angle is used as a unified analysis coordinate, and the crankshaft angle is converted into absolute time based on the engine speed. The time axis origin is set at 0°CA, and the time axis has positive and negative values. The calculation formula is as follows:

[0009] in, t Where Φ is absolute time and Φ is the crankshaft rotation angle. n Engine speed; Automatically identify the unit of the injection start time: if the original value of the injection start time is within the crankshaft angle range, the unit is determined to be crankshaft angle; if the original value of the injection start time is within the time range, the unit is determined to be time, and it is converted into the corresponding crankshaft angle through interpolation. At the same time, the cylinder pressure, average temperature and density corresponding to the injection start time are obtained through interpolation.

[0010] Furthermore, in S4, the maximum and minimum cylinder volumes are obtained based on the cylinder volume data in the thermal output file, and the compression ratio is calculated according to the following formula:

[0011] in, CR The compression ratio is... Max ( V () represents the maximum cylinder volume. Min ( V () represents the minimum cylinder volume.

[0012] Furthermore, in S5, for the cylinder pressure corresponding to the complete crankshaft rotation angle range, the instantaneous cylinder volume is calculated according to the following formula:

[0013] in, S For stroke, B Cylinder diameter, l The length of the link; The pressure sequence after truncation and patching is matched one-to-one with the instantaneous cylinder volume sequence obtained by solving, and a complete PV cycle data is constructed according to the same crankshaft angle coordinates. The PV cycle data is used for subsequent calculation of thermodynamic indicators such as indicated work, average indicated pressure, thermal efficiency, maximum pressure and pressure rise rate.

[0014] Furthermore, in S6, based on complete PV cycle data, the pressure-volume curve is integrated to obtain the indicated work:

[0015] in, The pressure inside the cylinder. This refers to the cylinder volume; Calculate the average indicated pressure using the following formula:

[0016] Calculate the indicated thermal efficiency using the following formula:

[0017] in, For the quality of oil spraying, It has a low calorific value as a fuel; The highest cylinder pressure was identified based on the fused pressure sequence. And its corresponding crankshaft angle, the maximum pressure rise rate is calculated based on the pressure gradient with respect to the crankshaft angle:

[0018] in, This is the change in pressure. This represents the change in crankshaft angle. The maximum pressure rise rate and its corresponding crankshaft angle are determined within the preset crankshaft angle search range.

[0019] Furthermore, in S6, the injection start point (SOI) and injection end point (EOI) are determined based on the injection start time and injection duration. After the injection start time, the position where the heat release rate first exceeds a preset threshold is searched as the combustion start point (SOC). Calculate the ignition delay period in crankshaft angle form based on the crankshaft angle difference between SOC and SOI:

[0020] And the ignition delay period is calculated in time form based on engine speed:

[0021] The cumulative heat release rate was normalized, and the crankshaft angles corresponding to the cumulative heat release rates of 5%, 10%, 50%, and 90% were obtained by interpolation and denoted as CA5, CA10, CA50, and CA90, respectively.

[0022] Furthermore, in S7, all the aforementioned steps are executed sequentially for multiple simulation conditions, and the engine parameters, injection parameters, boundary parameters, in-cylinder state parameters corresponding to the injection start time, PV cycle data and thermodynamic performance indicators of each condition are summarized. The summarized results will be output as a parameter comparison table, a thermal analysis table, a curve comparison graph, a pressure-volume dynamometer diagram, and a critical moment interval diagram; the critical moment interval diagram will include SOI, EOI, SOC, , CA5, CA10, CA50, and CA90 are arranged in sequence according to crankshaft rotation angle. The crankshaft rotation angle or zero time is used as the alignment reference to divide different combustion process intervals to achieve multi-condition comparative analysis.

[0023] A storage medium storing a computer program, which, when executed by a processor, implements the above-described batch extraction processing method for combustion characteristic parameters.

[0024] A computer device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described batch extraction and processing method for combustion characteristic parameters.

[0025] Compared with existing technologies, this invention achieves significant beneficial effects through the above technical solutions: This invention realizes the batch, standardization, and automated analysis of the thermodynamic process of three-dimensional combustion simulation of internal combustion engines, completely replacing the traditional manual operation mode of reading files one by one, extracting parameters, calculating indicators, and organizing plots, greatly reducing the workload of manual post-processing and significantly improving the efficiency of simulation result analysis; by unifying the crankshaft angle coordinate reference, adaptively identifying the injection timing unit, truncating and patching the cylinder pressure data, and reconstructing the complete cylinder volume and PV cycle, it effectively solves the problems of scattered simulation file sources, inconsistent crankshaft angle ranges, etc. It avoids data bias caused by manual processing, such as incomplete thermodynamic cycle data, and significantly improves the accuracy of analysis results. At the same time, the unified processing rules ensure the consistency of analysis standards and data traceability between different simulation examples and multiple operating conditions. It can automatically and accurately calculate various thermodynamic performance indicators and identify key combustion moments such as ignition delay period, CA5, CA10, CA50, and CA90. With standardized tables, curves, and interval diagrams, it can achieve intuitive comparison of multiple operating conditions, and provide comprehensive and reliable data support for the optimization of internal combustion engine combustion chamber structure, the adjustment of fuel injection strategy, and the comprehensive evaluation of overall engine thermal efficiency. Attached Figure Description

[0026] Figure 1 This is a flowchart of a method for batch extraction and processing of combustion characteristic parameters according to the present invention; Figure 2 This is a schematic diagram of the user interface and analysis results of an automated comparative analysis tool for batch thermodynamic processes used in three-dimensional combustion simulation of internal combustion engines. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Reference Figures 1-2 As shown, a method for batch extraction and processing of combustion characteristic parameters includes the following steps: S1. Batch acquire one or more internal combustion engine 3D combustion simulation working condition directories and complete the file integrity identification within the working condition directory; S2. Extract the engine basic parameters, boundary parameters, and injection parameters sequentially from the qualified files; S3. Read the thermal output data and unify the crankshaft angle coordinates, while performing unit adaptive recognition of the injection start time; S4. Calculate the compression ratio based on the read volume data, and perform truncation and patching processing on the cylinder pressure data; S5. Reconstruct the instantaneous cylinder volume by combining engine structural parameters, and build a complete thermodynamic cycle based on the completed cylinder pressure data and instantaneous volume data; S6. Calculate the thermodynamic performance indicators of the internal combustion engine based on the complete thermodynamic cycle and identify various key moments in the combustion process; S7. Perform batch comparison of calculation results for multiple simulation conditions and output standardized analysis results.

[0029] Specifically, this invention can complete batch processing and automatic thermodynamic process analysis of three-dimensional combustion simulation conditions for internal combustion engines. It can automatically complete a series of tasks, including obtaining the simulation condition directory, verifying file integrity, extracting multiple parameters, unifying data coordinates, identifying injection timing units, calculating compression ratios, processing cylinder pressure data, solving for instantaneous cylinder volume, and building a complete thermodynamic cycle. This eliminates the traditional work mode of manually opening files one by one, manually extracting parameters, and organizing data, effectively reducing manual workload and significantly improving the overall efficiency of simulation post-processing. This invention standardizes crankshaft angles and completes the truncation and patching of cylinder pressure data to construct complete thermodynamic cycle data. It effectively solves problems such as scattered simulation file sources, inconsistent crankshaft angle ranges, and incomplete PV cycle data, avoiding data deviations that are prone to occur during manual processing and ensuring the accuracy of data processing and analysis results. Meanwhile, this invention can automatically complete the calculation of various thermodynamic performance indicators and identify key combustion moments. It adopts unified processing rules throughout the process, ensuring that the analysis standards of different simulation conditions and calculation examples remain consistent, thus guaranteeing the consistency and traceability of the analysis results. Finally, it can perform batch comparison of data from multiple operating conditions and output standardized analysis results, clearly presenting the differences between various operating conditions. This provides solid and reliable data support for the optimization of internal combustion engine combustion chamber structure, fuel injection strategy optimization, and comprehensive evaluation of overall engine thermal efficiency.

[0030] Furthermore, in S1, the operating condition directory includes at least engine input files, boundary condition files, spray input files, cylinder pressure output files, and thermodynamic output files (input files have different formats for different software, such as *.in files for CONVERGE, *.cas files for FLUENT, *.inp files for AVL FIRE, and *.sim files for STAR-CCM+; output files include *.out, *.h5, *.csv, *.plt, etc., but in this embodiment, CONVERGE software is used as an example, and each of them is: engine.in, boundary.in, valve_lift.in, spray.in, spray.out, thermo.out; In S2, the cylinder bore, stroke, connecting rod length, engine speed, swirl ratio, piston boundary ID, cylinder liner boundary ID, and cylinder head boundary ID are extracted from the engine input file. The displacement is calculated by combining the cylinder bore and stroke, and the average piston speed is calculated by combining the engine speed and stroke. Based on the extracted piston boundary ID, cylinder liner boundary ID, and cylinder head boundary ID, the piston wall temperature, cylinder liner wall temperature, and cylinder head wall temperature are matched and read from the boundary condition file. The injector spatial position, injection start time, injection duration, total injection quantity, nozzle diameter, nozzle position, nozzle radial distance, nozzle axial distance, and spray angle are extracted from the spray input file.

[0031] Specifically, this invention clarifies the essential file types within the simulation condition catalog, ensuring the integrity of the raw data required for analysis from the source. This prevents interruptions in subsequent thermal analysis processes due to missing critical files. Simultaneously, it can automatically extract engine basic parameters, boundary parameters, and various injection parameters from different file types. Furthermore, it can automatically calculate displacement and average piston speed based on basic data such as cylinder bore, stroke, and speed. It also accurately matches and reads the wall temperature information corresponding to the piston, cylinder liner, and cylinder head based on boundary IDs. This eliminates the tedious manual operation of opening files one by one to search for, extract parameters, and manually convert related parameters, reducing workload and effectively avoiding data entry errors prone to occur during manual operation. It comprehensively and systematically extracts various structural parameters, temperature parameters, and injection parameters.

[0032] Furthermore, in S3, the crankshaft angle, pressure, average temperature, density, cumulative heat release rate, heat release rate, and cylinder volume data from the thermodynamic output file are read. The crankshaft angle is used as a unified analysis coordinate, and the crankshaft angle is converted into absolute time based on the engine speed. The time axis origin is set at 0°CA, and the time axis has positive and negative values. The calculation formula is as follows:

[0033] in, t Where Φ is absolute time and Φ is the crankshaft rotation angle. n Engine speed; Automatic identification of the unit of the injection start time: If the original value of the injection start time is within the crankshaft angle range, the unit is determined to be crankshaft angle; if the original value of the injection start time is within the time range, the unit is determined to be time, and it is converted into the corresponding crankshaft angle by interpolation. At the same time, the cylinder pressure, average temperature and density corresponding to the injection start time are obtained by interpolation. The interpolation is usually linear interpolation.

[0034] Specifically, this invention reads various core data from the thermal output file, such as crankshaft angle, pressure, average temperature, density, and heat release rate. It establishes the crankshaft angle as a unified analysis coordinate, uses 0°CA as the origin of the time axis and distinguishes between positive and negative time axes, and achieves precise conversion between crankshaft angle and absolute time using conversion formulas. This establishes a unified and standardized measurement system for all simulation data, effectively solving the problem of inaccurate comparison and analysis due to inconsistent coordinates and time bases for different simulation conditions. Simultaneously, this invention can automatically determine the unit type of the injection start time based on the numerical range. If it is determined to be in time format, it converts it to crankshaft angle format through interpolation. It can also simultaneously interpolate the corresponding in-cylinder pressure, average temperature, and density data at the injection start time. The entire process eliminates the need for manual unit identification, manual value conversion, and searching for corresponding operating parameters, simplifying the data preprocessing process, reducing manual operation burden, and avoiding errors and deviations caused by manual judgment and calculation. The resulting injection time and corresponding in-cylinder state data are accurate.

[0035] Furthermore, in S4, the maximum and minimum cylinder volumes are obtained based on the cylinder volume data in the thermal output file, and the compression ratio is calculated according to the following formula:

[0036] in, CR The compression ratio is... Max ( V () represents the maximum cylinder volume. Min ( V () represents the minimum cylinder volume.

[0037] Specifically, this invention automatically obtains the maximum and minimum cylinder volume values ​​from the cylinder volume data in the thermodynamic output file, and automatically calculates the compression ratio according to a predetermined formula. This eliminates the need for manual volume statistics and calculations, improving processing efficiency while effectively avoiding errors and deviations that are prone to occur during manual calculations. Simultaneously, this invention distinguishes between two types of pressure sequences to complete the truncation and patching of cylinder pressure data. Using cylinder pressure data across the entire crankshaft angle range as a base, it combines the pressure data from the thermodynamic output to replace and fuse data for corresponding intervals. This overcomes the limitations of limited crankshaft angle coverage and incomplete cylinder pressure data in conventional simulation conditions, ensuring the completeness and continuity of cylinder pressure data across the entire crankshaft angle range and unifying the application standards for multi-source cylinder pressure data.

[0038] Furthermore, in S5, for the cylinder pressure corresponding to the complete crankshaft rotation angle range, the instantaneous cylinder volume is calculated according to the following formula:

[0039] in, S For stroke, B Cylinder diameter,l The length of the link; The pressure sequence after truncation and patching is matched one-to-one with the instantaneous cylinder volume sequence obtained by solving, and a complete PV cycle data is constructed according to the same crankshaft angle coordinates. The PV cycle data is used for subsequent calculation of thermodynamic indicators such as indicated work, average indicated pressure, thermal efficiency, maximum pressure and pressure rise rate.

[0040] Specifically, this invention utilizes a predetermined calculation formula to automatically calculate the instantaneous cylinder volume within the entire crankshaft rotation range, eliminating the need for manual calculations based on engine structural parameters. This improves data processing efficiency and avoids errors introduced by manual calculations. The invention matches the truncated and patched pressure sequence with the calculated instantaneous cylinder volume sequence using a unified crankshaft rotation coordinate system, successfully constructing complete PV cycle data. This effectively solves the problems of incomplete thermodynamic cycle data and incomplete correspondence between pressure and volume data. The constructed PV cycle data can be directly applied to the calculation of various thermodynamic indicators such as indicated work, average indicated pressure, thermal efficiency, maximum pressure, and pressure rise rate. This provides complete, continuous, and highly matched basic data for subsequent thermodynamic performance analysis, ensuring the orderly conduct of various thermodynamic parameter analyses and guaranteeing the completeness and reliability of the final analysis results from a data perspective.

[0041] Furthermore, in S6, based on complete PV cycle data, the pressure-volume curve is integrated to obtain the indicated work:

[0042] in, The pressure inside the cylinder. This refers to the cylinder volume; Calculate the average indicated pressure using the following formula:

[0043] Calculate the indicated thermal efficiency using the following formula:

[0044] in, For the quality of oil spraying, It has a low calorific value as a fuel; The highest cylinder pressure was identified based on the fused pressure sequence. And its corresponding crankshaft angle, the maximum pressure rise rate is calculated based on the pressure gradient with respect to the crankshaft angle:

[0045] in, This is the change in pressure. This represents the change in crankshaft angle. Within a preset crankshaft angle search range, the maximum pressure rise rate and its corresponding crankshaft angle are determined, with the aim of limiting the pressure rise rate to the pressure increase generated by combustion.

[0046] Specifically, this invention relies on complete PV cycle data to automatically calculate the indicated work by integrating the pressure-volume curve. Combined with corresponding formulas, it automatically calculates the average indicated pressure and indicated thermal efficiency, completely eliminating manual integration and calculation of various thermodynamic parameters. This improves data processing efficiency while effectively reducing data deviations caused by manual calculations. Furthermore, this invention can automatically identify the highest cylinder pressure and its corresponding crankshaft angle from the fused pressure sequence. It obtains the maximum pressure rise rate through gradient calculation of pressure relative to the crankshaft angle and filters relevant parameters within a preset crankshaft angle search range, accurately pinpointing the pressure rise rate generated during combustion and avoiding interference from non-combustion interval data. The calculation of all thermodynamic performance parameters and the extraction of characteristic parameters follow a unified standard, ensuring the fairness and consistency of thermodynamic evaluation indicators under different simulation conditions. The obtained quantitative parameters accurately reflect the in-cylinder thermodynamic operating state of the internal combustion engine.

[0047] Furthermore, in S6, the injection start point (SOI) and injection end point (EOI) are determined based on the injection start time and injection duration. After the injection start time, the position where the heat release rate first exceeds a preset threshold is searched as the combustion start point (SOC). Calculate the ignition delay period in crankshaft angle form based on the crankshaft angle difference between SOC and SOI:

[0048] And the ignition delay period is calculated in time form based on engine speed:

[0049] The cumulative heat release rate was normalized, and the crankshaft angles corresponding to the cumulative heat release rates of 5%, 10%, 50%, and 90% were obtained by interpolation and denoted as CA5, CA10, CA50, and CA90, respectively.

[0050] Specifically, this invention can automatically determine the injection start and end points based on the injection start time and injection duration, and automatically retrieve the position where the heat release rate first reaches a preset threshold after the injection start time as the combustion start point, eliminating the need for manual data searching and judgment, thus significantly improving the efficiency of identifying key combustion nodes. This invention can calculate the ignition delay period in both crankshaft angle and time forms using corresponding formulas, enriching the expression of the ignition delay period and adapting to different analysis scenarios. The automated calculation method also effectively avoids data errors caused by manual conversion and calculation. Furthermore, after normalizing the cumulative heat release rate, this invention accurately obtains the crankshaft angles corresponding to cumulative heat release rates of 5%, 10%, 50%, and 90% through interpolation, namely CA5, CA10, CA50, and CA90, representing various combustion phase parameters. A unified processing standard is used throughout, ensuring the consistency and comparability of combustion phase parameters under different simulation conditions. The various key combustion moments and phase indicators obtained by the above methods can fully reflect the entire process of in-cylinder fuel injection, ignition, and combustion development of an internal combustion engine, and clearly present the differences in combustion characteristics under different operating conditions.

[0051] Furthermore, in S7, all the aforementioned steps are executed sequentially for multiple simulation conditions, and the engine parameters, injection parameters, boundary parameters, in-cylinder state parameters corresponding to the injection start time, PV cycle data and thermodynamic performance indicators of each condition are summarized. The summarized results will be output as a parameter comparison table, a thermal analysis table, a curve comparison graph, a pressure-volume dynamometer diagram, and a critical moment interval diagram; the critical moment interval diagram will include SOI, EOI, SOC, , CA5, CA10, CA50, and CA90 are arranged in sequence according to crankshaft rotation angle, and combustion process intervals are formed between different key events. This allows for a direct comparison of the differences in fuel injection, ignition, combustion development, and pressure rise processes under different operating conditions. The crankshaft rotation angle / time zero point is used as the alignment reference to achieve comparison between multiple operating conditions.

[0052] Specifically, this invention can sequentially complete the entire analysis process for multiple simulation conditions, and uniformly summarize the engine parameters, injection parameters, boundary parameters, in-cylinder state parameters corresponding to the injection start time, PV cycle data, and various thermodynamic performance indicators for each condition. This eliminates the tedious manual operation of sorting and collecting data across conditions, significantly improving the efficiency and regularity of multi-condition data summarization. This invention can output the summarized analysis results in multiple forms, including parameter comparison tables, thermodynamic analysis tables, curve comparison graphs, pressure-volume dynamometer diagrams, and key moment interval diagrams. These diverse presentation methods cater to both quantitative data retrieval and intuitive graphical analysis. The key moment interval diagram arranges the injection start point, injection end point, combustion start point, maximum cylinder pressure, maximum pressure rise rate, and each combustion phase node sequentially according to the crankshaft angle, using the crankshaft angle or time zero point as a unified alignment benchmark to divide different combustion process intervals. This clearly presents the differences in the entire process of injection, ignition, combustion development, and pressure changes under different simulation conditions.

[0053] A storage medium storing a computer program, which, when executed by a processor, implements the above-described batch extraction processing method for combustion characteristic parameters.

[0054] A computer device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described batch extraction and processing method for combustion characteristic parameters.

[0055] Specifically, the computer device provided by this invention is equipped with a runnable computer program. The internal memory of the device can stably store program code, as well as various types of original data, intermediate calculation data, and final analysis results of internal combustion engine simulation. After calling the program, the processor can automatically execute the entire batch thermodynamic process automatic comparison and analysis process of three-dimensional combustion simulation of internal combustion engines. The entire process completes a series of operations, including working condition file recognition, extraction of multiple parameters, data coordinate unification, cylinder pressure data processing, thermodynamic cycle construction, performance index calculation, identification of key combustion moments, and multi-working condition comparison output. This device relies on automated program operation to replace the traditional manual operation mode, and can continuously process multiple sets of simulation working conditions in batches, effectively improving the overall efficiency of post-simulation processing. At the same time, the device maintains a consistent standard when executing various calculations and judgment logics, avoiding the operational deviations, statistical errors, and inconsistent evaluation standards that are prone to occur in manual processing, and fully ensuring the accuracy, consistency, and traceability of all analysis data. Based on this computer equipment, the relevant analysis methods can be applied to the actual working scenarios of internal combustion engine combustion simulation. It can stably output diversified analysis results such as parameter tables, various comparison curves and indicator diagrams, providing a convenient and reliable hardware platform for internal combustion engine combustion chamber structure optimization, fuel injection strategy debugging and comprehensive evaluation of overall engine thermal efficiency, further improving the intelligence and practicality of simulation analysis work.

[0056] This invention is not limited to the above-described embodiments. Without departing from the spirit and essence of this invention, those skilled in the art can make equivalent substitutions or improvements to the sequence of steps, parameter settings, and specific implementation forms, all of which should fall within the protection scope of the claims of this invention.

Claims

1. A method for batch extraction and processing of combustion characteristic parameters, characterized in that, Includes the following steps: S1. Batch acquire one or more internal combustion engine 3D combustion simulation working condition directories and complete the file integrity identification within the working condition directory; S2. Extract the engine basic parameters, boundary parameters, and injection parameters sequentially from the qualified files; S3. Read the thermal output data and unify the crankshaft angle coordinates, while performing unit adaptive recognition of the injection start time; S4. Calculate the compression ratio based on the read volume data, and perform truncation and patching processing on the cylinder pressure data; S5. Reconstruct the instantaneous cylinder volume by combining engine structural parameters, and build a complete thermodynamic cycle based on the completed cylinder pressure data and instantaneous volume data; S6. Calculate the thermodynamic performance indicators of the internal combustion engine based on the complete thermodynamic cycle and identify various key moments in the combustion process; S7. Perform batch comparison of calculation results for multiple simulation conditions and output standardized analysis results.

2. The batch extraction and processing method for combustion characteristic parameters according to claim 1, characterized in that, In S1, the operating condition catalog includes at least the engine input file, boundary condition file, spray input file, cylinder pressure output file, and thermal output file; In S2, the cylinder bore, stroke, connecting rod length, engine speed, swirl ratio, piston boundary ID, cylinder liner boundary ID, and cylinder head boundary ID are extracted from the engine input file. The displacement is calculated by combining the cylinder bore and stroke, and the average piston speed is calculated by combining the engine speed and stroke. Based on the extracted piston boundary ID, cylinder liner boundary ID, and cylinder head boundary ID, the piston wall temperature, cylinder liner wall temperature, and cylinder head wall temperature are matched and read from the boundary condition file. The injector spatial position, injection start time, injection duration, total injection quantity, nozzle diameter, nozzle position, nozzle radial distance, nozzle axial distance, and spray angle are extracted from the spray input file.

3. The batch extraction and processing method for combustion characteristic parameters according to claim 2, characterized in that, In S3, the crankshaft angle, pressure, average temperature, density, cumulative heat release rate, heat release rate, and cylinder volume data are read from the thermodynamic output file. The crankshaft angle is used as the unified analysis coordinate, and the crankshaft angle is converted into absolute time according to the engine speed. 0°CA is used as the origin of the time axis, which has positive and negative values. The calculation formula is as follows: in, t Where Φ is absolute time and Φ is the crankshaft rotation angle. n Engine speed; Automatically identify the unit of the injection start time: if the original value of the injection start time is within the crankshaft angle range, the unit is determined to be crankshaft angle; if the original value of the injection start time is within the time range, the unit is determined to be time, and it is converted into the corresponding crankshaft angle through interpolation. At the same time, the cylinder pressure, average temperature and density corresponding to the injection start time are obtained through interpolation.

4. The batch extraction and processing method for combustion characteristic parameters according to claim 3, characterized in that, In S4, the maximum and minimum cylinder volumes are obtained from the cylinder volume data in the thermal output file, and the compression ratio is calculated using the following formula: in, CR The compression ratio is... Max ( V () represents the maximum cylinder volume. Min ( V () represents the minimum cylinder volume.

5. The batch extraction and processing method for combustion characteristic parameters according to claim 4, characterized in that, In S5, for the cylinder pressure corresponding to the complete crankshaft rotation angle range, the instantaneous cylinder volume is calculated according to the following formula: in, S For stroke, B Cylinder diameter, l The length of the link; The pressure sequence after truncation and patching is matched one-to-one with the instantaneous cylinder volume sequence obtained by solving, and a complete PV cycle data is constructed according to the same crankshaft angle coordinates. The PV cycle data is used for subsequent calculation of thermodynamic indicators such as indicated work, average indicated pressure, thermal efficiency, maximum pressure and pressure rise rate.

6. The batch extraction and processing method for combustion characteristic parameters according to claim 5, characterized in that, In S6, based on complete PV cycle data, the pressure-volume curve is integrated to obtain the indicated work: in, The pressure inside the cylinder. This refers to the cylinder volume; Calculate the average indicated pressure using the following formula: Calculate the indicated thermal efficiency using the following formula: in, For the quality of oil spraying, It has a low calorific value as a fuel; The highest cylinder pressure was identified based on the fused pressure sequence. And its corresponding crankshaft angle, the maximum pressure rise rate is calculated based on the pressure gradient with respect to the crankshaft angle: in, This is the change in pressure. This represents the change in crankshaft angle. The maximum pressure rise rate and its corresponding crankshaft angle are determined within the preset crankshaft angle search range.

7. The batch extraction and processing method for combustion characteristic parameters according to claim 6, characterized in that, In S6, the injection start point (SOI) and injection end point (EOI) are determined based on the injection start time and injection duration. After the injection start time, the position where the heat release rate first exceeds a preset threshold is searched as the combustion start point (SOC). Calculate the ignition delay period in crankshaft angle form based on the crankshaft angle difference between SOC and SOI: And the ignition delay period is calculated in time form based on engine speed: The cumulative heat release rate was normalized, and the crankshaft angles corresponding to the cumulative heat release rates of 5%, 10%, 50%, and 90% were obtained by interpolation and denoted as CA5, CA10, CA50, and CA90, respectively.

8. The batch extraction and processing method for combustion characteristic parameters according to claim 7, characterized in that, In S7, all the aforementioned steps are executed sequentially for multiple simulation conditions, and the engine parameters, injection parameters, boundary parameters, in-cylinder state parameters corresponding to the injection start time, PV cycle data and thermodynamic performance indicators of each condition are summarized. The summarized results are output as a parameter comparison table, a thermal analysis table, a curve comparison graph, a pressure-volume dynamometer diagram, and a critical moment interval diagram. The critical moment interval chart includes SOI, EOI, SOC, , CA5, CA10, CA50, and CA90 are arranged in sequence according to crankshaft rotation angle. The crankshaft rotation angle or zero time is used as the alignment reference to divide different combustion process intervals to achieve multi-condition comparative analysis.

9. A storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the batch extraction and processing method for combustion characteristic parameters as described in any one of claims 1-8.

10. A computer device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the batch extraction and processing method for combustion characteristic parameters according to any one of claims 1-8.

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