A modified small perturbation stability prediction model for axial compressors with circumferential inlet distortions is established and applied to investigate the effect of fore/aft-loaded rotor on compressor stabili...A modified small perturbation stability prediction model for axial compressors with circumferential inlet distortions is established and applied to investigate the effect of fore/aft-loaded rotor on compressor stability under circumferentially distorted inlet conditions.The inlet total pressure distribution downstream of the distortion screen is measured in experiments and employed for simulations which are implemented via time-space spectral method.The stall inception prediction results via the stability model indicate that the compressor with aft-loaded rotor not only performs better in terms of stability under uniform inlet,but also maintains a larger stability margin under circumferentially distorted inlet.The experiments for compressors with fore-loaded and aft-loaded rotor are respectively carried out.The results validate the reliability of numerical simulations and the predicted conclusion that the aft-loaded rotor is beneficial for compressor stability.Besides,the ability of the developed theoretical model for compressor stability prediction under circumferential distortions is confirmed.In addition,dynamic pressure signals at rotor tip measured in experiments illustrate that the circumferential distortion has little effect on the compressor stall pattern.展开更多
To reduce the propulsion system installation thrust loss under high angle of attack maneuvering,a control method based on real-time optimization of the integrated aeropropulsion is proposed.Firstly,based on data fitti...To reduce the propulsion system installation thrust loss under high angle of attack maneuvering,a control method based on real-time optimization of the integrated aeropropulsion is proposed.Firstly,based on data fitting and physical principle,an integrated onboard model of propulsion system is established,which can calculate various performance parameters of the propulsion system in real time,and has high accuracy and real-time performance.Secondly,to improve the compatibility of optimization real-time performance and search accuracy,the online optimization control of aero-propulsion system is realized based on an improved trust region algorithm.Finally,by controlling the auxiliary intake valve,a good match between inlet and engine is realized,which solves the problems of intake flow reducing and total pressure recovery coefficient declining,and improves the installation performance of propulsion system.The simulation results indicate that,compared with the conventional independent engine control,the real-time integrated optimization method reduces the installed thrust loss by 3.61%under the design condition,and 4.58%under the off-design condition.Furthermore,the simulation on HIL(Hardware-In-theLoop)platform verifies the real-time performance of integrated optimization method.展开更多
Based on the axial bed depth model of straight rotary kiln proposed by prior researchers,the equation of mean residence time of solids in carbon rotary kiln with variable diameter and turn-down rig was developed.Cold ...Based on the axial bed depth model of straight rotary kiln proposed by prior researchers,the equation of mean residence time of solids in carbon rotary kiln with variable diameter and turn-down rig was developed.Cold experiments were carried out on a laboratory rotary kiln under ambient conditions.The comparison between calculated results and experiment data showed that calculated results of the residence time of solids agreed well with measurements and the prediction error varied in a small range of-15%—+12%.No fitting parameter was necessary.The mass flow rate of solids increased and the mean residence time decreased with increasing kiln rotation speed and kiln slope.The mass flow rate of solids increased and the mean residence time might possibly decrease or increase with increasing dam height at the feed end.展开更多
基金The research presented here was supported by the National Natural Science Foundation of China(Nos.52306036 and 52325602)the Science Center for Gas Turbine Project,China(Nos.P2022-A-II-002-001 and P2022-C-II-003-001)+3 种基金the Project funded by China Postdoctoral Science Foundation(No.2022M720346)the National Science and Technology Major Projectc,China(Nos.Y2022-II-0003-0006 and Y2022-II-0002-0005)Also,the research is supported by the Key Laboratory of Pre-Research Management Centre,China(No.6142702200101)the Fundamental Research Funds for the Central Universities,China(Nos.YWF-23-Q-1009 and YWF-23-Q-1065).
文摘A modified small perturbation stability prediction model for axial compressors with circumferential inlet distortions is established and applied to investigate the effect of fore/aft-loaded rotor on compressor stability under circumferentially distorted inlet conditions.The inlet total pressure distribution downstream of the distortion screen is measured in experiments and employed for simulations which are implemented via time-space spectral method.The stall inception prediction results via the stability model indicate that the compressor with aft-loaded rotor not only performs better in terms of stability under uniform inlet,but also maintains a larger stability margin under circumferentially distorted inlet.The experiments for compressors with fore-loaded and aft-loaded rotor are respectively carried out.The results validate the reliability of numerical simulations and the predicted conclusion that the aft-loaded rotor is beneficial for compressor stability.Besides,the ability of the developed theoretical model for compressor stability prediction under circumferential distortions is confirmed.In addition,dynamic pressure signals at rotor tip measured in experiments illustrate that the circumferential distortion has little effect on the compressor stall pattern.
基金supported in part by the National Natural Science Foundation of China (Nos. 51906102 and 52176009)the National Science and Technology Major Project, China (Nos. J2019-II-0009-0053, J2019-I-0020-0019 and 2019III-0014-0058)+2 种基金the Innovation Centre for Advanced Aviation Power, China (Nos. HKCX2020-02-022 and HKCX2020-02-027)the Research on the Basic Problem of Intelligent Aero-engine, China (No. 2017-JCJQZD-047-21)the Fundamental Research Funds for the Central Universities, China (No. NZ2020002)
文摘To reduce the propulsion system installation thrust loss under high angle of attack maneuvering,a control method based on real-time optimization of the integrated aeropropulsion is proposed.Firstly,based on data fitting and physical principle,an integrated onboard model of propulsion system is established,which can calculate various performance parameters of the propulsion system in real time,and has high accuracy and real-time performance.Secondly,to improve the compatibility of optimization real-time performance and search accuracy,the online optimization control of aero-propulsion system is realized based on an improved trust region algorithm.Finally,by controlling the auxiliary intake valve,a good match between inlet and engine is realized,which solves the problems of intake flow reducing and total pressure recovery coefficient declining,and improves the installation performance of propulsion system.The simulation results indicate that,compared with the conventional independent engine control,the real-time integrated optimization method reduces the installed thrust loss by 3.61%under the design condition,and 4.58%under the off-design condition.Furthermore,the simulation on HIL(Hardware-In-theLoop)platform verifies the real-time performance of integrated optimization method.
文摘Based on the axial bed depth model of straight rotary kiln proposed by prior researchers,the equation of mean residence time of solids in carbon rotary kiln with variable diameter and turn-down rig was developed.Cold experiments were carried out on a laboratory rotary kiln under ambient conditions.The comparison between calculated results and experiment data showed that calculated results of the residence time of solids agreed well with measurements and the prediction error varied in a small range of-15%—+12%.No fitting parameter was necessary.The mass flow rate of solids increased and the mean residence time decreased with increasing kiln rotation speed and kiln slope.The mass flow rate of solids increased and the mean residence time might possibly decrease or increase with increasing dam height at the feed end.
