Abstract The temperature distribution and thermal Stresses induced by a temperature difference for steady state heat transfer in silicon carbide (SiC) ceramic tube heat exchanger with circular fins was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for the hoop stresses due to the structural and thermodynamic random variables. These results are used to identify the most critical design variables in order to optimize the design and make it cost effective. The probabilistic analysis leads to the selection of the appropriate measurements to be used in structural and heat transfer analysis and to the identification of both the most critical measurements and parameters.
{"title":"Uncertainty quantification by probabilistic analysis of circular fins","authors":"R. Gorla","doi":"10.1515/tjj-2023-0043","DOIUrl":"https://doi.org/10.1515/tjj-2023-0043","url":null,"abstract":"Abstract The temperature distribution and thermal Stresses induced by a temperature difference for steady state heat transfer in silicon carbide (SiC) ceramic tube heat exchanger with circular fins was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for the hoop stresses due to the structural and thermodynamic random variables. These results are used to identify the most critical design variables in order to optimize the design and make it cost effective. The probabilistic analysis leads to the selection of the appropriate measurements to be used in structural and heat transfer analysis and to the identification of both the most critical measurements and parameters.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41350449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In order to improve the real-time performance of the aero-engine Component-Level Model (CLM) while ensuring accuracy, a method for the Calculation of Thermodynamic Parameters of Working Fluids (CTPWF) based on a Neural Network and Newton Raphson (NN-NR) is proposed. In this method, the enthalpy or entropy under different fuel-air ratio and humidity conditions is mapped to temperature by a neural network, and the mapping output is used as the initial solution of Newton Raphson (NR) iteration. Then, a high-precision solution can be obtained through a few iterations, which avoids the shortcoming that the traditional method uses a fixed initial solution that leads to too many iterative steps. This effectively reduces the number of iterative steps and improves the calculation efficiency. This method is applied to the aero-thermodynamic calculation of each component of an engine CLM, which improves the accuracy and real-time performance of the CLM. The simulation results show that, compared to the traditional method, the proposed method improves the accuracy of the CTPWF and can reduces the single aero-thermodynamic calculation time by 25 % when humidity is not considered and by 47 % when humidity is considered. This effectively improves the real-time performance of the CLM.
{"title":"Research on a high-precision real-time improvement method for aero-engine component-level model","authors":"Qiangang Zheng, Liangliang Li, Haibo Zhang, Jiajie Chen","doi":"10.1515/tjj-2023-0022","DOIUrl":"https://doi.org/10.1515/tjj-2023-0022","url":null,"abstract":"Abstract In order to improve the real-time performance of the aero-engine Component-Level Model (CLM) while ensuring accuracy, a method for the Calculation of Thermodynamic Parameters of Working Fluids (CTPWF) based on a Neural Network and Newton Raphson (NN-NR) is proposed. In this method, the enthalpy or entropy under different fuel-air ratio and humidity conditions is mapped to temperature by a neural network, and the mapping output is used as the initial solution of Newton Raphson (NR) iteration. Then, a high-precision solution can be obtained through a few iterations, which avoids the shortcoming that the traditional method uses a fixed initial solution that leads to too many iterative steps. This effectively reduces the number of iterative steps and improves the calculation efficiency. This method is applied to the aero-thermodynamic calculation of each component of an engine CLM, which improves the accuracy and real-time performance of the CLM. The simulation results show that, compared to the traditional method, the proposed method improves the accuracy of the CTPWF and can reduces the single aero-thermodynamic calculation time by 25 % when humidity is not considered and by 47 % when humidity is considered. This effectively improves the real-time performance of the CLM.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49281352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhiyuan Cao, Xin Li, Cheng Song, Ping Huang, Jing Yang, Bo Liu
Abstract To reveal the influence of distortion of S-duct on the flow field and performance of transonic fan, full annulus unsteady numerical simulation was carried out under S-duct/fan integrated condition. This study focuses on the coupling flow of S-duct/fan integrated condition under peak efficiency (PE) condition and near stall (NS) condition. Results show that, compared with the condition that S-duct or fan is investigated alone, the distortion of S-duct is suppressed under S-duct/fan integrated condition. The curved structure of S-duct is the important reason for the flow migration from undistorted region to distortion region. Higher inlet relative Mach number and more work input of the rotor are observed in the counter-swirl region. The flow separation in S-duct is weakened under NS condition compared with that of PE condition. Counter-swirl region of blade tip has larger region of blockage, and rotating stall inception is most likely to occur in this region.
{"title":"Numerical study on the effect of distortion of S-duct on flow field and performance of a full annulus transonic fan","authors":"Zhiyuan Cao, Xin Li, Cheng Song, Ping Huang, Jing Yang, Bo Liu","doi":"10.1515/tjj-2023-0019","DOIUrl":"https://doi.org/10.1515/tjj-2023-0019","url":null,"abstract":"Abstract To reveal the influence of distortion of S-duct on the flow field and performance of transonic fan, full annulus unsteady numerical simulation was carried out under S-duct/fan integrated condition. This study focuses on the coupling flow of S-duct/fan integrated condition under peak efficiency (PE) condition and near stall (NS) condition. Results show that, compared with the condition that S-duct or fan is investigated alone, the distortion of S-duct is suppressed under S-duct/fan integrated condition. The curved structure of S-duct is the important reason for the flow migration from undistorted region to distortion region. Higher inlet relative Mach number and more work input of the rotor are observed in the counter-swirl region. The flow separation in S-duct is weakened under NS condition compared with that of PE condition. Counter-swirl region of blade tip has larger region of blockage, and rotating stall inception is most likely to occur in this region.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45220626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xin Li, Tong Meng, Lingchen Zhou, Weiwei Li, L. Ji
Abstract In this work, a combined design of blade and endwall using the Extended Free Form Deformation technique is proposed and implemented on a transonic compressor rotor (the NASA Rotor 67). The best combined design is explored by numerical investigations and optimization via Kriging surrogate model method. As a result, by only modifying the hub and blade under 15 % span, the peak adiabatic efficiency is increased by 0.4 % and the overall aerodynamic performance for all operating conditions is also improved. An analysis shows that the enlarged dihedral angle between the hub and blade restrains boundary layer intersection and development. Meanwhile, the optimized hub changes the pressure distribution and prevents migration of cross-flow. As a result, the low-energy flow in the corner is accelerated downstream and the separation is limited, leading to an effective improvement in throughflow capability and aerodynamic performance in the corner region.
{"title":"Optimization and numerical investigation of combined design of blade and endwall on rotor 67","authors":"Xin Li, Tong Meng, Lingchen Zhou, Weiwei Li, L. Ji","doi":"10.1515/tjj-2023-0011","DOIUrl":"https://doi.org/10.1515/tjj-2023-0011","url":null,"abstract":"Abstract In this work, a combined design of blade and endwall using the Extended Free Form Deformation technique is proposed and implemented on a transonic compressor rotor (the NASA Rotor 67). The best combined design is explored by numerical investigations and optimization via Kriging surrogate model method. As a result, by only modifying the hub and blade under 15 % span, the peak adiabatic efficiency is increased by 0.4 % and the overall aerodynamic performance for all operating conditions is also improved. An analysis shows that the enlarged dihedral angle between the hub and blade restrains boundary layer intersection and development. Meanwhile, the optimized hub changes the pressure distribution and prevents migration of cross-flow. As a result, the low-energy flow in the corner is accelerated downstream and the separation is limited, leading to an effective improvement in throughflow capability and aerodynamic performance in the corner region.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46754241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Effect of free boundary on the flow field characteristics of a single expansion nozzle has been studied experimentally and computationally. The single expansion nozzles studied in this investigation are a convergent-divergent nozzle of rectangular cross-section with convergent-divergent wall on one side and a flat wall on the opposite side, and an identical convergent-divergent ramp with its top open to atmosphere. The studies have been carried out at nozzle pressure ratios 2, 3, 4 and 5. The results show that the single expansion nozzle with wall boundary is able to deliver the flow with Mach number around 1.5, at nozzle pressure ratios of 4 and 5 even with the single expansion. The nozzle with free boundary, the wall static pressure is appreciably lower than that of nozzle with closed boundary and the exit Mach number is 1.5 for NPR 4 and 1.75 for NPR 5. That is, at the exit, the single expansion nozzle with free boundary delivers higher Mach number compared to single expansion nozzle with wall boundary for NPR 5.
{"title":"Effect of free boundary on the performance of single expansion nozzle","authors":"Dakshina Murthy Inturi, Lovaraju Pinnam, Ramachandra Raju Vegesna","doi":"10.1515/tjj-2023-0034","DOIUrl":"https://doi.org/10.1515/tjj-2023-0034","url":null,"abstract":"Abstract Effect of free boundary on the flow field characteristics of a single expansion nozzle has been studied experimentally and computationally. The single expansion nozzles studied in this investigation are a convergent-divergent nozzle of rectangular cross-section with convergent-divergent wall on one side and a flat wall on the opposite side, and an identical convergent-divergent ramp with its top open to atmosphere. The studies have been carried out at nozzle pressure ratios 2, 3, 4 and 5. The results show that the single expansion nozzle with wall boundary is able to deliver the flow with Mach number around 1.5, at nozzle pressure ratios of 4 and 5 even with the single expansion. The nozzle with free boundary, the wall static pressure is appreciably lower than that of nozzle with closed boundary and the exit Mach number is 1.5 for NPR 4 and 1.75 for NPR 5. That is, at the exit, the single expansion nozzle with free boundary delivers higher Mach number compared to single expansion nozzle with wall boundary for NPR 5.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48241685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Rotating machinery, such as turbo-jet engines, operate at a high rotational speed and passes through critical zones. The dynamic response of high-speed machines is critical for long-term stability and functioning. In this work, a fast and effective method for detecting coupling misalignment utilising time-frequency analysis (TFA) based on both the adaptive noise added complete ensemble empirical mode decomposition and wavelet-based denoising is presented. This novel and innovative method detect the coupling misalignment feature via the amplitude modulation aspect in the envelope analysis of the fault-containing intrinsic mode function. The Hilbert spectrum analysis provides spontaneous frequency and spectral energy in the time-frequency domain. The experiments were performed for various rotor accelerations and combined parallel and angular coupling misalignments using a laboratory test rig. The suggested approach gives excellent denoising efficiency and can improve misalignment identification accuracy. Additionally, it may be highly helpful for machinery that starts and stops often.
{"title":"Experimental investigation on a Jeffcott rotor with combined coupling misalignment using time-frequency analysis","authors":"Ashutosh Kumar, P. Sathujoda, N. Bhalla","doi":"10.1515/tjj-2023-0033","DOIUrl":"https://doi.org/10.1515/tjj-2023-0033","url":null,"abstract":"Abstract Rotating machinery, such as turbo-jet engines, operate at a high rotational speed and passes through critical zones. The dynamic response of high-speed machines is critical for long-term stability and functioning. In this work, a fast and effective method for detecting coupling misalignment utilising time-frequency analysis (TFA) based on both the adaptive noise added complete ensemble empirical mode decomposition and wavelet-based denoising is presented. This novel and innovative method detect the coupling misalignment feature via the amplitude modulation aspect in the envelope analysis of the fault-containing intrinsic mode function. The Hilbert spectrum analysis provides spontaneous frequency and spectral energy in the time-frequency domain. The experiments were performed for various rotor accelerations and combined parallel and angular coupling misalignments using a laboratory test rig. The suggested approach gives excellent denoising efficiency and can improve misalignment identification accuracy. Additionally, it may be highly helpful for machinery that starts and stops often.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48209374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Film and jet impingement cooling are widely used techniques in gas turbine vane and blade cooling. The present work investigates and compares the flow structure of a film-cooled flat plate with a hybrid cooling scheme. The hybrid cooling scheme combines both impingement hole and film holes and is named combined impingement-film (IFC) cooling. Experimental validation and computational analyses are carried out on a flat plate with film holes. Different flow parameters, such as velocity pattern, Turbulent kinetic energy, and streamline flow structure, are compared for the two cases in different regions of the flat plate. It is observed that the hybrid scheme shows advantages over film cooling. The jet-to-jet interaction, jet crossflow interaction, and vortex formation are the main factors affecting film cooling performance. There is a 52 % drop in turbulent kinetic energy for the hybrid cooling compared to the film cooling at the film hole exit. More mixing in the coolant and mainstream interaction is observed for the FC case than in the IFC.
{"title":"Flow structure comparison of film cooling versus hybrid cooling: a CFD study","authors":"R. Panda, A. K. Pujari, B. Gudla","doi":"10.1515/tjj-2022-0058","DOIUrl":"https://doi.org/10.1515/tjj-2022-0058","url":null,"abstract":"Abstract Film and jet impingement cooling are widely used techniques in gas turbine vane and blade cooling. The present work investigates and compares the flow structure of a film-cooled flat plate with a hybrid cooling scheme. The hybrid cooling scheme combines both impingement hole and film holes and is named combined impingement-film (IFC) cooling. Experimental validation and computational analyses are carried out on a flat plate with film holes. Different flow parameters, such as velocity pattern, Turbulent kinetic energy, and streamline flow structure, are compared for the two cases in different regions of the flat plate. It is observed that the hybrid scheme shows advantages over film cooling. The jet-to-jet interaction, jet crossflow interaction, and vortex formation are the main factors affecting film cooling performance. There is a 52 % drop in turbulent kinetic energy for the hybrid cooling compared to the film cooling at the film hole exit. More mixing in the coolant and mainstream interaction is observed for the FC case than in the IFC.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47246041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lei Shi, Ruilin Jiang, Chen-lei Huang, Shuhan Guo, Guoshun Chen
Abstract The entire compression system of DGEN380 was selected to study the degradation of aerodynamic characteristics caused by erosion of the leading edge. Numerical simulations under different degrees of leading edge erosion were performed. It was found that the leading edge erosion causes a significant decrease in operability from 70 % of the blade height to the tip, and mainly affects the subsequent flow field in the bypass. At 90 % of blade height, the isentropic efficiency and total pressure ratio of the blade with leading edge erosion are reduced compared to the origin blade. Afterwards, the thrust equation was introduced to analyze the effect of leading edge erosion on the thrust loss under different operating conditions of the aircraft. Among the three operating conditions, the thrust loss rate of the cruise condition was the largest, which provided a reference for the subsequent evaluation of the blade repair condition.
{"title":"The aerodynamic performance degradation analysis of a small high bypass turbofan engine compression system with fan rotor blade leading edge erosion","authors":"Lei Shi, Ruilin Jiang, Chen-lei Huang, Shuhan Guo, Guoshun Chen","doi":"10.1515/tjj-2023-0031","DOIUrl":"https://doi.org/10.1515/tjj-2023-0031","url":null,"abstract":"Abstract The entire compression system of DGEN380 was selected to study the degradation of aerodynamic characteristics caused by erosion of the leading edge. Numerical simulations under different degrees of leading edge erosion were performed. It was found that the leading edge erosion causes a significant decrease in operability from 70 % of the blade height to the tip, and mainly affects the subsequent flow field in the bypass. At 90 % of blade height, the isentropic efficiency and total pressure ratio of the blade with leading edge erosion are reduced compared to the origin blade. Afterwards, the thrust equation was introduced to analyze the effect of leading edge erosion on the thrust loss under different operating conditions of the aircraft. Among the three operating conditions, the thrust loss rate of the cruise condition was the largest, which provided a reference for the subsequent evaluation of the blade repair condition.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44986717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract With the advancement of the supersonic aero propulsion system, optimizing the combined performance of inlet/engine integration has become increasingly crucial. To solve the coupling inlet/engine problem, a quasi-one-dimensional inlet modeling and drag calculation method are proposed, integrated performance seeking control (PSC) based on the neighborhood-based speciation differential evolution-grey wolf optimizer (NSDE-GWO) is presented and quantitatively analyses the influence of variable geometry inlet regulation on performance. The results reveal that the optimization effect of the ramp angle adjustment is generally better than that of the bleed adjustment, and the NSDE-GWO hybrid algorithm achieves remarkable optimization solutions in all three different modes. The PSC with variable geometry inlet adjustment provides more additional potential for optimization compared with fixed geometry inlet, and the performance can be maximized by adjusting both the bleed adjustment and the ramp angle. This study maximizes the exploitation of potential and has theoretical guidance and practical engineering significance.
{"title":"Installed performance seeking control based on supersonic variable inlet/engine coupling model","authors":"Chen Wang, Ximing Sun, Xian Du","doi":"10.1515/tjj-2023-0030","DOIUrl":"https://doi.org/10.1515/tjj-2023-0030","url":null,"abstract":"Abstract With the advancement of the supersonic aero propulsion system, optimizing the combined performance of inlet/engine integration has become increasingly crucial. To solve the coupling inlet/engine problem, a quasi-one-dimensional inlet modeling and drag calculation method are proposed, integrated performance seeking control (PSC) based on the neighborhood-based speciation differential evolution-grey wolf optimizer (NSDE-GWO) is presented and quantitatively analyses the influence of variable geometry inlet regulation on performance. The results reveal that the optimization effect of the ramp angle adjustment is generally better than that of the bleed adjustment, and the NSDE-GWO hybrid algorithm achieves remarkable optimization solutions in all three different modes. The PSC with variable geometry inlet adjustment provides more additional potential for optimization compared with fixed geometry inlet, and the performance can be maximized by adjusting both the bleed adjustment and the ramp angle. This study maximizes the exploitation of potential and has theoretical guidance and practical engineering significance.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42531928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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