针对利用传统水平集法(level set method,LSM)进行热传导结构拓扑优化计算过程复杂及计算效率低等问题,本文将参数化水平集法(parametric level set method,PLSM)引入热传导结构拓扑优化中,通过紧支径向基函数(compactly supported-radi...针对利用传统水平集法(level set method,LSM)进行热传导结构拓扑优化计算过程复杂及计算效率低等问题,本文将参数化水平集法(parametric level set method,PLSM)引入热传导结构拓扑优化中,通过紧支径向基函数(compactly supported-radial basis functions,CS-RBFs)插值初始的水平集函数,建立了以CS-RBFs的插值系数为设计变量,结构的散热弱度为目标函数以及材料体积为约束的热传导结构拓扑优化模型,再通过移动渐近线法(method of moving asymptotes,MMA)更新CS-RBFs的插值系数,结构的优化过程转化为插值系数的更新过程,由此得到最优拓扑。数值算例结果表明利用参数化水平集法(PLSM)与传统的水平集法(LSM)得到的拓扑结果基本一致,验证了该法的可行性和有效性。展开更多
The study of transient heat conduction in multilayered slabs is widely used in various engineering fields. In this paper, the transient heat conduction in multilayered slabs with general boundary conditions and arbitr...The study of transient heat conduction in multilayered slabs is widely used in various engineering fields. In this paper, the transient heat conduction in multilayered slabs with general boundary conditions and arbitrary heat generations is analysed. The boundary conditions are general and include various combinations of Dirichlet, Neumann or Robin boundary conditions at either surface. Moreover, arbitrary heat generations in the slabs are taken into account. The solutions are derived by basic methods, including the superposition method, separation variable method and orthogonal expansion method. The simplified double-layered analytical solution is validated by a numerical method and applied to predicting the temporal and spatial distribution of the temperature inside a landfill. It indicates the ability of the proposed analytical solutions for solving the wide range of applied transient heat conduction problems.展开更多
The dynamic properties of proton conductivity along hydrogen-bonded molecular systems, for example, ice crystal, with structure disorder or damping and finite temperatures exposed in an externally applied electric-fie...The dynamic properties of proton conductivity along hydrogen-bonded molecular systems, for example, ice crystal, with structure disorder or damping and finite temperatures exposed in an externally applied electric-field have been numerically studied by Runge-Kutta way in our soliton model. The results obtained show that the proton-soliton is very robust against the structure disorder including the fluctuation of the force constant and disorder in the sequence of masses and thermal perturbation and damping of medium, the velocity of its conductivity increases with increasing of the externally applied electric-field and decreasing of the damping coefficient of medium, but the proton-soliton disperses for quite great fluctuation of the "force constant and damping coefficient. In the numerical simulation we find that the proton-soliton in our model is thermally stable in a large region of temperature of T ≤ 273 K under influences of damping and externally applied electric-field in ice crvstal. This shows that our model is available and appropriate to ice.展开更多
文摘针对利用传统水平集法(level set method,LSM)进行热传导结构拓扑优化计算过程复杂及计算效率低等问题,本文将参数化水平集法(parametric level set method,PLSM)引入热传导结构拓扑优化中,通过紧支径向基函数(compactly supported-radial basis functions,CS-RBFs)插值初始的水平集函数,建立了以CS-RBFs的插值系数为设计变量,结构的散热弱度为目标函数以及材料体积为约束的热传导结构拓扑优化模型,再通过移动渐近线法(method of moving asymptotes,MMA)更新CS-RBFs的插值系数,结构的优化过程转化为插值系数的更新过程,由此得到最优拓扑。数值算例结果表明利用参数化水平集法(PLSM)与传统的水平集法(LSM)得到的拓扑结果基本一致,验证了该法的可行性和有效性。
基金Projects(41530637,41877222,41702290)supported by the National Natural Science Foundation of China
文摘The study of transient heat conduction in multilayered slabs is widely used in various engineering fields. In this paper, the transient heat conduction in multilayered slabs with general boundary conditions and arbitrary heat generations is analysed. The boundary conditions are general and include various combinations of Dirichlet, Neumann or Robin boundary conditions at either surface. Moreover, arbitrary heat generations in the slabs are taken into account. The solutions are derived by basic methods, including the superposition method, separation variable method and orthogonal expansion method. The simplified double-layered analytical solution is validated by a numerical method and applied to predicting the temporal and spatial distribution of the temperature inside a landfill. It indicates the ability of the proposed analytical solutions for solving the wide range of applied transient heat conduction problems.
基金The project supported by National Natural Science Foundation of China under Grant No. 90306015
文摘The dynamic properties of proton conductivity along hydrogen-bonded molecular systems, for example, ice crystal, with structure disorder or damping and finite temperatures exposed in an externally applied electric-field have been numerically studied by Runge-Kutta way in our soliton model. The results obtained show that the proton-soliton is very robust against the structure disorder including the fluctuation of the force constant and disorder in the sequence of masses and thermal perturbation and damping of medium, the velocity of its conductivity increases with increasing of the externally applied electric-field and decreasing of the damping coefficient of medium, but the proton-soliton disperses for quite great fluctuation of the "force constant and damping coefficient. In the numerical simulation we find that the proton-soliton in our model is thermally stable in a large region of temperature of T ≤ 273 K under influences of damping and externally applied electric-field in ice crvstal. This shows that our model is available and appropriate to ice.