A theoretical investigation of fluid flow,heat transfer and solidification(solidification transfer phenomena,STP)was presented which coupled with direct-current(DC)magnetic fields in a high-speed strip-casting metal d...A theoretical investigation of fluid flow,heat transfer and solidification(solidification transfer phenomena,STP)was presented which coupled with direct-current(DC)magnetic fields in a high-speed strip-casting metal delivery system.The bidirectional interaction between the STP and DC magnetic fields was simplified as a unilateral one,and the fully coupled solidification transport equations were numerically solved by the finite volume method(FVM).While the magnetic field contours for a localized DC magnetic field were calculated by software ANSYS and then incorporated into a three-dimensional(3-D)steady model of the liquid cavity in the mold by means of indirect coupling.A new FVM-based direct-SIMPLE algorithm was adopted to solve the iterations of pressure-velocity(P-V).The braking effects of DC magnetic fields with various configurations were evaluated and compared with those without static magnetic field(SMF).The results show that 0.6 T magnetic field with combination configuration contributes to forming an isokinetic feeding of melt,the re-circulation zone is shifted towards the back wall of reservoir,and the velocity difference on the direction of height decreases from 0.1 m/s to 0.Furthermore,the thickness of solidified skull increases uniformly from 0.45 mm to 1.36 mm on the chilled substrate(belt)near the exit.展开更多
基金Projects(51071062,51271068,51274077)supported by the National Natural Science Foundation of ChinaProject(2011CB605504)supported by the National Basic Research Program(973 Program)of China
文摘A theoretical investigation of fluid flow,heat transfer and solidification(solidification transfer phenomena,STP)was presented which coupled with direct-current(DC)magnetic fields in a high-speed strip-casting metal delivery system.The bidirectional interaction between the STP and DC magnetic fields was simplified as a unilateral one,and the fully coupled solidification transport equations were numerically solved by the finite volume method(FVM).While the magnetic field contours for a localized DC magnetic field were calculated by software ANSYS and then incorporated into a three-dimensional(3-D)steady model of the liquid cavity in the mold by means of indirect coupling.A new FVM-based direct-SIMPLE algorithm was adopted to solve the iterations of pressure-velocity(P-V).The braking effects of DC magnetic fields with various configurations were evaluated and compared with those without static magnetic field(SMF).The results show that 0.6 T magnetic field with combination configuration contributes to forming an isokinetic feeding of melt,the re-circulation zone is shifted towards the back wall of reservoir,and the velocity difference on the direction of height decreases from 0.1 m/s to 0.Furthermore,the thickness of solidified skull increases uniformly from 0.45 mm to 1.36 mm on the chilled substrate(belt)near the exit.
文摘在物理模拟实验的基础上,采用基于标准k-ε湍流模型的三维稳态流动与磁场耦合模型,对电磁制动(electromagnetic braking,EMBr)条件下板坯连铸结晶器中的金属流场进行数值模拟,研究了磁场强度及其分布对结晶器内金属流动的影响,并与物理模拟结果进行了对比,进一步揭示了在物理模拟中受传感器数量等限制所无法观察到的一些细微现象或局部流态及流动行为.结果表明,在流动控制结晶器(flow control mold,FC Mold)电磁制动方式下,结晶器内流场具有复杂的三维特性.此时必须注意结晶器液面流速过慢所导致的表面夹杂、横裂等问题.合适、有效的电磁制动也应与连铸工艺相匹配.
