The radial multiple jets-in-crossflow mixing structure(RMJCMS) is extensively used in industrial manufacture. In this research, the effects of thickness of injection ring on mixing performance and factors influencing ...The radial multiple jets-in-crossflow mixing structure(RMJCMS) is extensively used in industrial manufacture. In this research, the effects of thickness of injection ring on mixing performance and factors influencing the mixing performance of RMJCMS were discussed based on the results of computational fluid dynamics. The simulation results showed that the dimensionless mixing distance, with the increase of the thickness of injection ring, drops from 1.1 to 0.18 first and then increases to 0.27 while the uniformity of flux monotonously improves, manifesting that the consistency of flux is not the single element determining the mixing performance. Analyzing the simulation results, a conclusion was drawn that the consistency of flux, penetration mode and interaction among injection flows which can be altered by adjusting the thickness of injection ring, determine the mixing performance of RMJCMS jointly. That is to say, in RMJCMS an injection ring with a suitable thickness can realize the function of injection and rectification simultaneously, which not only improves the mixing performance but also reduces the complexity of RMJCMS as well.展开更多
Turbulent jet flows with noncircular nozzle inlet are investigated by using a Reynolds Stress Model. In order to analyze the effects of noncircular inlet, the cross section of inlet are selected as circular, square, a...Turbulent jet flows with noncircular nozzle inlet are investigated by using a Reynolds Stress Model. In order to analyze the effects of noncircular inlet, the cross section of inlet are selected as circular, square, and equilateral triangular shape. The jet half-width, vorticity thickness, and developments of the secondary flow are presented. From the result, it is confirmed that the secondary flows of square and equilateral triangular nozzle are more vigorous than that of the circular jet. This development of secondary flows is closely related to the variations of vortical motions in axial and azimuthal directions.展开更多
制备了锆钛酸铅(PZT)悬浮液,采用电射流沉积(EJD)技术,在硅衬底上沉积了PZT厚膜。研究了电射流沉积高度、流量及悬浮液混合条件对厚膜致密性的影响。结果表明:降低电射流沉积高度和流量有助于提高沉积PZT厚膜致密性;采用球磨方法充分混...制备了锆钛酸铅(PZT)悬浮液,采用电射流沉积(EJD)技术,在硅衬底上沉积了PZT厚膜。研究了电射流沉积高度、流量及悬浮液混合条件对厚膜致密性的影响。结果表明:降低电射流沉积高度和流量有助于提高沉积PZT厚膜致密性;采用球磨方法充分混合PZT悬浮液,沉积的PZT厚膜致密性明显提高。采用优化的电射流沉积参数和球磨20 h的PZT悬浮液,制备了10μm无裂纹PZT厚膜,其压电常数d33为67 p C·N-1,相对介电常数εr为255。展开更多
基金Supported by the National Natural Science Foundation of China,China(21522602,21776092,91534202,91534122,51673063,51672082)Basic Research Program of Shanghai,China(15JC1401300,17JC1402300)+2 种基金Social Development Program of Shanghai,China(17DZ1200900)Innovation Program of Shanghai Municipal Education Commission,ChinaFundamental Research Funds for the Central Universities,China(222201718002).
文摘The radial multiple jets-in-crossflow mixing structure(RMJCMS) is extensively used in industrial manufacture. In this research, the effects of thickness of injection ring on mixing performance and factors influencing the mixing performance of RMJCMS were discussed based on the results of computational fluid dynamics. The simulation results showed that the dimensionless mixing distance, with the increase of the thickness of injection ring, drops from 1.1 to 0.18 first and then increases to 0.27 while the uniformity of flux monotonously improves, manifesting that the consistency of flux is not the single element determining the mixing performance. Analyzing the simulation results, a conclusion was drawn that the consistency of flux, penetration mode and interaction among injection flows which can be altered by adjusting the thickness of injection ring, determine the mixing performance of RMJCMS jointly. That is to say, in RMJCMS an injection ring with a suitable thickness can realize the function of injection and rectification simultaneously, which not only improves the mixing performance but also reduces the complexity of RMJCMS as well.
文摘Turbulent jet flows with noncircular nozzle inlet are investigated by using a Reynolds Stress Model. In order to analyze the effects of noncircular inlet, the cross section of inlet are selected as circular, square, and equilateral triangular shape. The jet half-width, vorticity thickness, and developments of the secondary flow are presented. From the result, it is confirmed that the secondary flows of square and equilateral triangular nozzle are more vigorous than that of the circular jet. This development of secondary flows is closely related to the variations of vortical motions in axial and azimuthal directions.
文摘制备了锆钛酸铅(PZT)悬浮液,采用电射流沉积(EJD)技术,在硅衬底上沉积了PZT厚膜。研究了电射流沉积高度、流量及悬浮液混合条件对厚膜致密性的影响。结果表明:降低电射流沉积高度和流量有助于提高沉积PZT厚膜致密性;采用球磨方法充分混合PZT悬浮液,沉积的PZT厚膜致密性明显提高。采用优化的电射流沉积参数和球磨20 h的PZT悬浮液,制备了10μm无裂纹PZT厚膜,其压电常数d33为67 p C·N-1,相对介电常数εr为255。
