用欧拉法处理气相场的同时用基于拉格朗日法的直接数值模拟蒙特卡罗(direct simulation Monte Carlo,DSMC)法处理离散颗粒场,对循环流化床烟气脱硫塔内气固两相流动特性及其优化进行了数值模拟。基于非结构网格进行数值求解,采用四向耦...用欧拉法处理气相场的同时用基于拉格朗日法的直接数值模拟蒙特卡罗(direct simulation Monte Carlo,DSMC)法处理离散颗粒场,对循环流化床烟气脱硫塔内气固两相流动特性及其优化进行了数值模拟。基于非结构网格进行数值求解,采用四向耦合方法严格地考虑颗粒–流体、颗粒–颗粒、颗粒–器壁间相互作用,并应用高效的非结构网格搜索法,实现气固相间一一映射的耦合作用与反馈。获得了加装导流板组前后,脱硫塔内气固流动特征、轴向速度分布以及固相颗粒浓度分布,同时对影响颗粒停留时间及颗粒碰撞率的关键因素进行了分析。结果证实了调节脱硫塔内多相流动的必要性与有效性;调节后,塔内两相流动及其分布呈理想对称状态,塔内空间得到了充分利用,各粒径档颗粒停留时间比较一致;颗粒停留时间与气相场分布及颗粒物性密切相关;调节后,床内颗粒碰撞率明显低于调节前。展开更多
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
文摘用欧拉法处理气相场的同时用基于拉格朗日法的直接数值模拟蒙特卡罗(direct simulation Monte Carlo,DSMC)法处理离散颗粒场,对循环流化床烟气脱硫塔内气固两相流动特性及其优化进行了数值模拟。基于非结构网格进行数值求解,采用四向耦合方法严格地考虑颗粒–流体、颗粒–颗粒、颗粒–器壁间相互作用,并应用高效的非结构网格搜索法,实现气固相间一一映射的耦合作用与反馈。获得了加装导流板组前后,脱硫塔内气固流动特征、轴向速度分布以及固相颗粒浓度分布,同时对影响颗粒停留时间及颗粒碰撞率的关键因素进行了分析。结果证实了调节脱硫塔内多相流动的必要性与有效性;调节后,塔内两相流动及其分布呈理想对称状态,塔内空间得到了充分利用,各粒径档颗粒停留时间比较一致;颗粒停留时间与气相场分布及颗粒物性密切相关;调节后,床内颗粒碰撞率明显低于调节前。
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.
