An opposite combined vertical linear electromagnetic stirring(CV-LEMS)was proposed,which is applied in the final solidification zone of bloom continuous casting.The melt flow,heat transfer,and solidification under CV-...An opposite combined vertical linear electromagnetic stirring(CV-LEMS)was proposed,which is applied in the final solidification zone of bloom continuous casting.The melt flow,heat transfer,and solidification under CV-LEMS were investigated by establishing a three-dimensional numerical simulation model and a pilot continuous casting simulation experiment and compared with the conventional rotary electromagnetic stirring(REMS).The results show that a longitudinally symmetric linear magnetic field is formed in the liquid core of the bloom by applying CV-LEMS,which induces a strong longitudinal circulation flow both on the inner arc side and the outer arc side in the liquid core of the bloom.The height of the melt longitudinal effective mixing range under CV-LEMS reaches 0.9 m,which is greater than that of the REMS and makes up for the deficiency of REMS sensitivity to the position of the final solidification zone.CV-LEMS strongly promotes the mixing of upper melt with high temperature and the lower part melt with low temperature in the liquid core,improves the uniformity of melt temperature distribution and significantly increases the melt temperature near the solidification front,and the width of the liquid core increases by 4.2 mm at maximum.This shows that the appliction of CV-LEMS is more helpful to strengthen the feeding effect of the upper melt to the solidification shrinkage of the lower melt than the conventional REMS and inhibits the formation of porosity,shrinkage cavity and crack defects in the center of the bloom.展开更多
In this paper,a two-step iteration method is established which can be viewed as a generalization of the existing modulus-based methods for vertical linear complementarity problems given by He and Vong(Appl.Math.Lett.1...In this paper,a two-step iteration method is established which can be viewed as a generalization of the existing modulus-based methods for vertical linear complementarity problems given by He and Vong(Appl.Math.Lett.134:108344,2022).The convergence analysis of the proposed method is established,which can improve the existing results.Numerical examples show that the proposed method is efficient with the two-step technique.展开更多
A one_step smoothing Newton method is proposed for solving the vertical linear complementarity problem based on the so_called aggregation function. The proposed algorithm has the following good features: (ⅰ) It solve...A one_step smoothing Newton method is proposed for solving the vertical linear complementarity problem based on the so_called aggregation function. The proposed algorithm has the following good features: (ⅰ) It solves only one linear system of equations and does only one line search at each iteration; (ⅱ) It is well_defined for the vertical linear complementarity problem with vertical block P 0 matrix and any accumulation point of iteration sequence is its solution.Moreover, the iteration sequence is bounded for the vertical linear complementarity problem with vertical block P 0+R 0 matrix; (ⅲ) It has both global linear and local quadratic convergence without strict complementarity. Many existing smoothing Newton methods do not have the property (ⅲ).展开更多
In this paper,we discuss the perturbation analysis of the extended vertical linear complementarity problem(EVLCP).Under the assumption of the row W-property,we derive several absolute and relative perturbation bounds ...In this paper,we discuss the perturbation analysis of the extended vertical linear complementarity problem(EVLCP).Under the assumption of the row W-property,we derive several absolute and relative perturbation bounds of EVLCP,which extend some existing results.Several numerical examples are given to show the proposed bounds.展开更多
基金the National Natural Science Foundation of China(Grant No.U1760206 and Grant No.51574083)the 111 Project(2.0)of China(No.BP0719037)for the financial support。
文摘An opposite combined vertical linear electromagnetic stirring(CV-LEMS)was proposed,which is applied in the final solidification zone of bloom continuous casting.The melt flow,heat transfer,and solidification under CV-LEMS were investigated by establishing a three-dimensional numerical simulation model and a pilot continuous casting simulation experiment and compared with the conventional rotary electromagnetic stirring(REMS).The results show that a longitudinally symmetric linear magnetic field is formed in the liquid core of the bloom by applying CV-LEMS,which induces a strong longitudinal circulation flow both on the inner arc side and the outer arc side in the liquid core of the bloom.The height of the melt longitudinal effective mixing range under CV-LEMS reaches 0.9 m,which is greater than that of the REMS and makes up for the deficiency of REMS sensitivity to the position of the final solidification zone.CV-LEMS strongly promotes the mixing of upper melt with high temperature and the lower part melt with low temperature in the liquid core,improves the uniformity of melt temperature distribution and significantly increases the melt temperature near the solidification front,and the width of the liquid core increases by 4.2 mm at maximum.This shows that the appliction of CV-LEMS is more helpful to strengthen the feeding effect of the upper melt to the solidification shrinkage of the lower melt than the conventional REMS and inhibits the formation of porosity,shrinkage cavity and crack defects in the center of the bloom.
基金supported by the Scientific Computing Research Innovation Team of Guangdong Province(no.2021KCXTD052)the Science and Technology Development Fund,Macao SAR(no.0096/2022/A,0151/2022/A)+3 种基金University of Macao(no.MYRG2020-00035-FST,MYRG2022-00076-FST)the Guangdong Key Construction Discipline Research Capacity Enhancement Project(no.2022ZDJS049)Technology Planning Project of Shaoguan(no.210716094530390)the ScienceFoundation of Shaoguan University(no.SZ2020KJ01).
文摘In this paper,a two-step iteration method is established which can be viewed as a generalization of the existing modulus-based methods for vertical linear complementarity problems given by He and Vong(Appl.Math.Lett.134:108344,2022).The convergence analysis of the proposed method is established,which can improve the existing results.Numerical examples show that the proposed method is efficient with the two-step technique.
文摘A one_step smoothing Newton method is proposed for solving the vertical linear complementarity problem based on the so_called aggregation function. The proposed algorithm has the following good features: (ⅰ) It solves only one linear system of equations and does only one line search at each iteration; (ⅱ) It is well_defined for the vertical linear complementarity problem with vertical block P 0 matrix and any accumulation point of iteration sequence is its solution.Moreover, the iteration sequence is bounded for the vertical linear complementarity problem with vertical block P 0+R 0 matrix; (ⅲ) It has both global linear and local quadratic convergence without strict complementarity. Many existing smoothing Newton methods do not have the property (ⅲ).
基金supported by the National Natural Science Foundation of China(Nos.11961082,12071159 and U1811464).
文摘In this paper,we discuss the perturbation analysis of the extended vertical linear complementarity problem(EVLCP).Under the assumption of the row W-property,we derive several absolute and relative perturbation bounds of EVLCP,which extend some existing results.Several numerical examples are given to show the proposed bounds.
