The disadvantage remaining in 3D scanning system and its reasons are discussed. A new host-and-slave structure with high speed image acquisition and processing system is proposed to quicken the image processing and im...The disadvantage remaining in 3D scanning system and its reasons are discussed. A new host-and-slave structure with high speed image acquisition and processing system is proposed to quicken the image processing and improve the performance of 3D scanning system.展开更多
This paper focuses on investigating the interaction effects for swirl and bluff-body in stabilized flame process. Particle image velocimetry was used to measure velocity fields in three burners. First, the comparison ...This paper focuses on investigating the interaction effects for swirl and bluff-body in stabilized flame process. Particle image velocimetry was used to measure velocity fields in three burners. First, the comparison of flames in bluff-body stabilized burners with and without swirl is presented. The results of the experiments present the variations of bluff-body stabilized flame when swirl is added into burner: the maximum reverse flow velocity and the maximum mean average radial velocity decrease; the maximum radial rootmean squared fluctuating (rms) velocity increases; the values of the axial velocity peak on the side of nozzle axis are lower, and the distance between the peak and centerline is bigger; the location of the maximum radial rms velocity moves to the outlet of annular air-flow from central recirculation zone (CRZ). Then, the comparison of flames in swirl burners with and without bluff-body is provided. The results of the experiments show the changes of swirling flame when bluff-body is added into swirl burner: the air vortex in the CRZ moves to the burner; the peak values of axial mean and rms velocity decrease; the distance between centerline and the mean axial and rms velocity peak increase; the peak of mean radial velocity decreases, and the peak of rms raidial velocity increase. The data from this experiment can also be established as benchmarks for the development and validation of combustion numerical simulations.展开更多
Monitoring and control of combustion flames in utility boilers are required in order to optimize combustion conditions.This paper presents an instrumentation system for the concurrent measurement of the temperature di...Monitoring and control of combustion flames in utility boilers are required in order to optimize combustion conditions.This paper presents an instrumentation system for the concurrent measurement of the temperature distributionand soot concentration of flames developed on the two-color principle. This system consists of an endoscope,an optical assembly with optical filters, a CCD camera, a frame grabber and associated image processingsoftware. Experiments are performed on a methane-air combustor and the temperature fields and the soot concentrationscorresponding to the flame images are obtained. The results have demonstrated that the system is capableof performing on-line measurement of flame and temperature distribution, providing temporal and spatial characterizationof the combustion process. In addition, the combination of advanced optical sensing and digital imageprocessing technique can help to define the threshold by the analysis of the background noise. Furthermore, theutilization of the filter technique can enhance the image presentation effect to an extent.展开更多
文摘The disadvantage remaining in 3D scanning system and its reasons are discussed. A new host-and-slave structure with high speed image acquisition and processing system is proposed to quicken the image processing and improve the performance of 3D scanning system.
基金supported by National Basic Research Program of China (973 Program).No.2007CB210102
文摘This paper focuses on investigating the interaction effects for swirl and bluff-body in stabilized flame process. Particle image velocimetry was used to measure velocity fields in three burners. First, the comparison of flames in bluff-body stabilized burners with and without swirl is presented. The results of the experiments present the variations of bluff-body stabilized flame when swirl is added into burner: the maximum reverse flow velocity and the maximum mean average radial velocity decrease; the maximum radial rootmean squared fluctuating (rms) velocity increases; the values of the axial velocity peak on the side of nozzle axis are lower, and the distance between the peak and centerline is bigger; the location of the maximum radial rms velocity moves to the outlet of annular air-flow from central recirculation zone (CRZ). Then, the comparison of flames in swirl burners with and without bluff-body is provided. The results of the experiments show the changes of swirling flame when bluff-body is added into swirl burner: the air vortex in the CRZ moves to the burner; the peak values of axial mean and rms velocity decrease; the distance between centerline and the mean axial and rms velocity peak increase; the peak of mean radial velocity decreases, and the peak of rms raidial velocity increase. The data from this experiment can also be established as benchmarks for the development and validation of combustion numerical simulations.
基金the National High Technology Research and Development of China (863 Program) (2006AA05A103)the National Natural Science Fund (grant No. 40501017, grant No. 50706053)
文摘Monitoring and control of combustion flames in utility boilers are required in order to optimize combustion conditions.This paper presents an instrumentation system for the concurrent measurement of the temperature distributionand soot concentration of flames developed on the two-color principle. This system consists of an endoscope,an optical assembly with optical filters, a CCD camera, a frame grabber and associated image processingsoftware. Experiments are performed on a methane-air combustor and the temperature fields and the soot concentrationscorresponding to the flame images are obtained. The results have demonstrated that the system is capableof performing on-line measurement of flame and temperature distribution, providing temporal and spatial characterizationof the combustion process. In addition, the combination of advanced optical sensing and digital imageprocessing technique can help to define the threshold by the analysis of the background noise. Furthermore, theutilization of the filter technique can enhance the image presentation effect to an extent.
