The investigation was carried out on the technical problems of finishing the inner surface of elbow parts and the action mechanism of particles in elbow precision machining by abrasive flow.This work was analyzed and ...The investigation was carried out on the technical problems of finishing the inner surface of elbow parts and the action mechanism of particles in elbow precision machining by abrasive flow.This work was analyzed and researched by combining theory,numerical and experimental methods.The direct simulation Monte Carlo(DSMC)method and the finite element analysis method were combined to reveal the random collision of particles during the precision machining of abrasive flow.Under different inlet velocity,volume fraction and abrasive particle size,the dynamic pressure and turbulence flow energy of abrasive flow in elbow were analyzed,and the machining mechanism of particles on the wall and the influence of different machining parameters on the precision machining quality of abrasive flow were obtained.The test results show the order of the influence of different parameters on the quality of abrasive flow precision machining and establish the optimal process parameters.The results of the surface morphology before and after the precision machining of the inner surface of the elbow are discussed,and the surface roughness Ra value is reduced from 1.125μm to 0.295μm after the precision machining of the abrasive flow.The application of DSMC method provides special insights for the development of abrasive flow technology.展开更多
研究旨在通过仿真实验揭示红外偏振成像系统在浮空器平台海雾背景下的探测优势。首先,基于偏振双向反射分布函数,分析了偏振特性随观测角度变化的规律,研究结果表明红外偏振在浮空器斜视成像中的适用性。其次,借助蒙特卡罗方法和最小可...研究旨在通过仿真实验揭示红外偏振成像系统在浮空器平台海雾背景下的探测优势。首先,基于偏振双向反射分布函数,分析了偏振特性随观测角度变化的规律,研究结果表明红外偏振在浮空器斜视成像中的适用性。其次,借助蒙特卡罗方法和最小可分辨温差(Minimum Resolvable Temperature Difference,MRTD)模型,构建了红外偏振成像系统的最大作用距离模型,从而验证了红外偏振成像相较于红外强度成像在海雾背景下特征保持和探测距离上存在优势。为红外偏振技术在浮空器平台上的部署应用,提供了理论分析和仿真依据。展开更多
基金Projects(51206011,U1937201)supported by the National Natural Science Foundation of ChinaProject(20200301040RQ)supported by the Science and Technology Development Program of Jilin Province,China+1 种基金Project(JJKH20190541KJ)supported by the Education Department of Jilin Province,ChinaProject(18DY017)supported by Changchun Science and Technology Program of Changchun City,China。
文摘The investigation was carried out on the technical problems of finishing the inner surface of elbow parts and the action mechanism of particles in elbow precision machining by abrasive flow.This work was analyzed and researched by combining theory,numerical and experimental methods.The direct simulation Monte Carlo(DSMC)method and the finite element analysis method were combined to reveal the random collision of particles during the precision machining of abrasive flow.Under different inlet velocity,volume fraction and abrasive particle size,the dynamic pressure and turbulence flow energy of abrasive flow in elbow were analyzed,and the machining mechanism of particles on the wall and the influence of different machining parameters on the precision machining quality of abrasive flow were obtained.The test results show the order of the influence of different parameters on the quality of abrasive flow precision machining and establish the optimal process parameters.The results of the surface morphology before and after the precision machining of the inner surface of the elbow are discussed,and the surface roughness Ra value is reduced from 1.125μm to 0.295μm after the precision machining of the abrasive flow.The application of DSMC method provides special insights for the development of abrasive flow technology.
文摘研究旨在通过仿真实验揭示红外偏振成像系统在浮空器平台海雾背景下的探测优势。首先,基于偏振双向反射分布函数,分析了偏振特性随观测角度变化的规律,研究结果表明红外偏振在浮空器斜视成像中的适用性。其次,借助蒙特卡罗方法和最小可分辨温差(Minimum Resolvable Temperature Difference,MRTD)模型,构建了红外偏振成像系统的最大作用距离模型,从而验证了红外偏振成像相较于红外强度成像在海雾背景下特征保持和探测距离上存在优势。为红外偏振技术在浮空器平台上的部署应用,提供了理论分析和仿真依据。
