By inspecting and analyzing the debris, which is the most direct and important information units in the lubricating oil, we can monitor the machine condition to predict its failure. The debris monitoring and analyzing...By inspecting and analyzing the debris, which is the most direct and important information units in the lubricating oil, we can monitor the machine condition to predict its failure. The debris monitoring and analyzing system (DMAS) is developed from the traditional iron spectrum technology, and has such characteristics as ease for debris separating, forecasting machine failure automatically and accurately in time and so on. The fundamental theory, components and its application in aeroengine health monitoring of DMAS are presented.展开更多
Particle breakage has a significant influence on the stress-strain and strength behavior of rockfill material.A breakage critical state theory(BCST)was proposed to describe the evolution of particle breakage.The break...Particle breakage has a significant influence on the stress-strain and strength behavior of rockfill material.A breakage critical state theory(BCST)was proposed to describe the evolution of particle breakage.The breakage critical state line in the breakage critical state theory was correlated with the breakage factor,which was fundamentally different from that of the original critical state theory.A simple elastoplastic constitutive model was developed for rockfill in the frame of BCST.An associated flow rule was adopted in this model.Isotropic,contractive and distortional hardening rules were suggested in view of the particle breakage.It was observed that the proposed model could well represent the complex deformation behaviors of rockfill material,such as the strain hardening,post-peak strain softening,volumetric contraction,volumetric expansion,and particle breakage under different initial confining pressures.展开更多
With the rapid development of circulating fluidized bed(CFB)technology in different fields,the disadvantages of conventional non-mechanical valves are becoming more apparent,and they are not suitable to be used in com...With the rapid development of circulating fluidized bed(CFB)technology in different fields,the disadvantages of conventional non-mechanical valves are becoming more apparent,and they are not suitable to be used in complex CFB systems.In this paper,a novel non-mechanical valve named the jet-control valve is presented which can avoid the fluidization of solid particles.The feasibility and performance characteristics of the new valve are investigated with a cold-model dual CFB.The results show that compared with the conventional non-mechanical valve,the jet-control valve can transfer solid particles steadily over a larger range,prevent artesian flow,and improve the leakage characteristics.The effects of the operating parameters and structural parameters on the minimum aeration velocity,solid flow rate,and maximum solid flow rate are studied.A two-valve model is proposed to explain the transport capacity of the valve for one jet pipe.A semi-theoretical expression is obtained based on the experimental data with a maximum deviation of 30%providing useful guide for scaling-up the design.展开更多
The particle breakage during specimen compaction had more significant influence on the position of the breakage critical-state line(BCSL)of Tacheng rockfill material(TRM)in the e-lnp’plane than the particle breakage ...The particle breakage during specimen compaction had more significant influence on the position of the breakage critical-state line(BCSL)of Tacheng rockfill material(TRM)in the e-lnp’plane than the particle breakage during shearing,based on the large-scale triaxial compression tests on TRM in a wide range of densities and pressures.The state-dependent dilatancy and the plastic modulus were correlated to the breakage index,based on the formulations of the BCSL of TRM in the e-lnp’plane.The state-dependent model considering particle breakage was proposed for TRM within the framework of the generalized plasticity theory.The proposed model contained fourteen material constants.The test data of TRM from Group A were adopted to determine these material constants,while the test data from Group B were used independently to validate the model predictive capacity.The comparisons between model simulations and test data illustrated that the model with consideration of particle breakage could well represent the stress-strain behaviors of TRM,e.g.,the strain hardening and volumetric contraction behaviors at a loose state and the strain softening and volumetric expansion behaviors at a dense state,and also the particle breakage behaviors of TRM.展开更多
文摘By inspecting and analyzing the debris, which is the most direct and important information units in the lubricating oil, we can monitor the machine condition to predict its failure. The debris monitoring and analyzing system (DMAS) is developed from the traditional iron spectrum technology, and has such characteristics as ease for debris separating, forecasting machine failure automatically and accurately in time and so on. The fundamental theory, components and its application in aeroengine health monitoring of DMAS are presented.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.106112015CDJXY200008)China Scholarship Council(Grant No.201306710022)
文摘Particle breakage has a significant influence on the stress-strain and strength behavior of rockfill material.A breakage critical state theory(BCST)was proposed to describe the evolution of particle breakage.The breakage critical state line in the breakage critical state theory was correlated with the breakage factor,which was fundamentally different from that of the original critical state theory.A simple elastoplastic constitutive model was developed for rockfill in the frame of BCST.An associated flow rule was adopted in this model.Isotropic,contractive and distortional hardening rules were suggested in view of the particle breakage.It was observed that the proposed model could well represent the complex deformation behaviors of rockfill material,such as the strain hardening,post-peak strain softening,volumetric contraction,volumetric expansion,and particle breakage under different initial confining pressures.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA07010300)
文摘With the rapid development of circulating fluidized bed(CFB)technology in different fields,the disadvantages of conventional non-mechanical valves are becoming more apparent,and they are not suitable to be used in complex CFB systems.In this paper,a novel non-mechanical valve named the jet-control valve is presented which can avoid the fluidization of solid particles.The feasibility and performance characteristics of the new valve are investigated with a cold-model dual CFB.The results show that compared with the conventional non-mechanical valve,the jet-control valve can transfer solid particles steadily over a larger range,prevent artesian flow,and improve the leakage characteristics.The effects of the operating parameters and structural parameters on the minimum aeration velocity,solid flow rate,and maximum solid flow rate are studied.A two-valve model is proposed to explain the transport capacity of the valve for one jet pipe.A semi-theoretical expression is obtained based on the experimental data with a maximum deviation of 30%providing useful guide for scaling-up the design.
基金supported by the National Natural Science Foundation for Distinguished Young Scholar(Grant No.50825901)the 111 Project(Grant No.B13024)+2 种基金the Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT1125)the Project supported by the National Natural Science Foundation of China(Grant No.51379067)the Fundamental Research Funds for the Central Universities(Grant No.2011B14514)
文摘The particle breakage during specimen compaction had more significant influence on the position of the breakage critical-state line(BCSL)of Tacheng rockfill material(TRM)in the e-lnp’plane than the particle breakage during shearing,based on the large-scale triaxial compression tests on TRM in a wide range of densities and pressures.The state-dependent dilatancy and the plastic modulus were correlated to the breakage index,based on the formulations of the BCSL of TRM in the e-lnp’plane.The state-dependent model considering particle breakage was proposed for TRM within the framework of the generalized plasticity theory.The proposed model contained fourteen material constants.The test data of TRM from Group A were adopted to determine these material constants,while the test data from Group B were used independently to validate the model predictive capacity.The comparisons between model simulations and test data illustrated that the model with consideration of particle breakage could well represent the stress-strain behaviors of TRM,e.g.,the strain hardening and volumetric contraction behaviors at a loose state and the strain softening and volumetric expansion behaviors at a dense state,and also the particle breakage behaviors of TRM.
