Based on the analyses of aluminum melt flow, solidification, heat transfer during the process of twin-roll casting, a coupling mathematical model of aluminum thin-gauge high-speed casting was developed, which included...Based on the analyses of aluminum melt flow, solidification, heat transfer during the process of twin-roll casting, a coupling mathematical model of aluminum thin-gauge high-speed casting was developed, which included the casting roller shell. At the same time, Galerkin method was adopted to solve the coupling model. The fluid field and temperature field of aluminum melt in casting zone, the temperature field and thermal stress field of roller shells were simulated by the coupling model. When the casting velocity is 7m/min, and the thickness of strip is 2mm, the circumfluent area comes into being in the casting zone, and the mushy zone dominates the casting zone, while the temperature of melt decreases rapidly as it approaches the rollers. The temperature of the roller shell varies periodically with the rotation of roller, and reaches the highest temperature in the casting zone, while the temperature of roller shell decreases gradually as it leaves the casting zone. The difference of thermal stress between the inner surface and outer surface of the roller shell is very large, and the outer surface suffers tensile-compressive stress.展开更多
(Re)Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have attracted considerable concern because of their outstanding current carrying capacity in magnetic fields of high strengths.A huge electromagnetic force is gener...(Re)Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have attracted considerable concern because of their outstanding current carrying capacity in magnetic fields of high strengths.A huge electromagnetic force is generated in the superconducting coil when conducting large currents in strong magnetic field.Thus,management of stress and strain has become a key technical challenge for the stability and safety of superconducting coil during operation.To accurately predict the electro-magnetic and mechanical characteristics of superconducting coil in strong magnetic field,an electromechanical model on the basis of the H-formulation and arbitrary Lagrangian-Eulerian(ALE)method is proposed here with FE software.To verify the proposed model,the simulation outcomes of the coil during magnetization are compared with the experimental outcomes.The coupling effect of magnet at high field strengths is dependent on the position of the coil.To reduce the screening current effect,the overshoot method with plateau is found superior to the traditional overshoot method,and an increase in the stabilization time can decrease the maximum value of stress.Finally,the electromechanical behaviors of single winding coil and two-tapes co-winding coil are compared.展开更多
文摘Based on the analyses of aluminum melt flow, solidification, heat transfer during the process of twin-roll casting, a coupling mathematical model of aluminum thin-gauge high-speed casting was developed, which included the casting roller shell. At the same time, Galerkin method was adopted to solve the coupling model. The fluid field and temperature field of aluminum melt in casting zone, the temperature field and thermal stress field of roller shells were simulated by the coupling model. When the casting velocity is 7m/min, and the thickness of strip is 2mm, the circumfluent area comes into being in the casting zone, and the mushy zone dominates the casting zone, while the temperature of melt decreases rapidly as it approaches the rollers. The temperature of the roller shell varies periodically with the rotation of roller, and reaches the highest temperature in the casting zone, while the temperature of roller shell decreases gradually as it leaves the casting zone. The difference of thermal stress between the inner surface and outer surface of the roller shell is very large, and the outer surface suffers tensile-compressive stress.
基金National Natural Science Foundation of China(Nos.U2241267,12172155 and 12302278)National Key Research and Development Program of China(No.2023YFA1607304)+1 种基金Major Scientific and Technological Special Project of Gansu Province(23ZDKA0009)Fundamental Research Funds for the Central Universities(No.lzujbky-2022-48).
文摘(Re)Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have attracted considerable concern because of their outstanding current carrying capacity in magnetic fields of high strengths.A huge electromagnetic force is generated in the superconducting coil when conducting large currents in strong magnetic field.Thus,management of stress and strain has become a key technical challenge for the stability and safety of superconducting coil during operation.To accurately predict the electro-magnetic and mechanical characteristics of superconducting coil in strong magnetic field,an electromechanical model on the basis of the H-formulation and arbitrary Lagrangian-Eulerian(ALE)method is proposed here with FE software.To verify the proposed model,the simulation outcomes of the coil during magnetization are compared with the experimental outcomes.The coupling effect of magnet at high field strengths is dependent on the position of the coil.To reduce the screening current effect,the overshoot method with plateau is found superior to the traditional overshoot method,and an increase in the stabilization time can decrease the maximum value of stress.Finally,the electromechanical behaviors of single winding coil and two-tapes co-winding coil are compared.
