两步法作为反应堆数值计算中的主流方法,因其受制于组件均匀化计算和堆芯扩散近似计算中引入的简化假设,对于精细化模型的计算可靠性需要进一步研究。基于DRAGON/DONJON计算BEAVRS 2.02(Benchmark for Evaluation And Validation of Rea...两步法作为反应堆数值计算中的主流方法,因其受制于组件均匀化计算和堆芯扩散近似计算中引入的简化假设,对于精细化模型的计算可靠性需要进一步研究。基于DRAGON/DONJON计算BEAVRS 2.02(Benchmark for Evaluation And Validation of Reactor Simulations Rev.2.0.2)基准题在热态零功率状态下的各项参数,先对组件进行输运计算,获得均匀化少群常数;再使用少群常数完成全堆芯扩散计算,最后比较了传统均匀化、一次多区均匀化和多次多区均匀化三种方案的计算误差。结果表明:本文计算结果与基准值相比吻合良好,临界硼浓度的误差在5×10^(-5)以内,控制棒价值的误差在5×10^(-4)以内。进一步对比裂变率发现,采用一次多区均匀化方案能将非对称燃料组件及相邻组件的平均误差从5.62%降低至3.345%,检验了两步法在精细化模型计算中的适用性。展开更多
The present paper aims at giving some general ideas concerning the micromechanical approach of the strength of a porous material. It is shown that its determination theoretically amounts to solving a nonlinear boundar...The present paper aims at giving some general ideas concerning the micromechanical approach of the strength of a porous material. It is shown that its determination theoretically amounts to solving a nonlinear boundary value problem defined on a representative elementary volume(REV). The principle of nonlinear homogenization is illustrated based on the case of a solid phase having a Green’s strength criterion. An original refinement of the so-called secant method(based on two reference strains) is also provided. The paper also describes the main feature of the Gurson’s model which implements the principle of limit analysis on a conceptual model of hollow sphere. The last part of the paper gives some ideas concerning poromechanical couplings.展开更多
文摘两步法作为反应堆数值计算中的主流方法,因其受制于组件均匀化计算和堆芯扩散近似计算中引入的简化假设,对于精细化模型的计算可靠性需要进一步研究。基于DRAGON/DONJON计算BEAVRS 2.02(Benchmark for Evaluation And Validation of Reactor Simulations Rev.2.0.2)基准题在热态零功率状态下的各项参数,先对组件进行输运计算,获得均匀化少群常数;再使用少群常数完成全堆芯扩散计算,最后比较了传统均匀化、一次多区均匀化和多次多区均匀化三种方案的计算误差。结果表明:本文计算结果与基准值相比吻合良好,临界硼浓度的误差在5×10^(-5)以内,控制棒价值的误差在5×10^(-4)以内。进一步对比裂变率发现,采用一次多区均匀化方案能将非对称燃料组件及相邻组件的平均误差从5.62%降低至3.345%,检验了两步法在精细化模型计算中的适用性。
文摘The present paper aims at giving some general ideas concerning the micromechanical approach of the strength of a porous material. It is shown that its determination theoretically amounts to solving a nonlinear boundary value problem defined on a representative elementary volume(REV). The principle of nonlinear homogenization is illustrated based on the case of a solid phase having a Green’s strength criterion. An original refinement of the so-called secant method(based on two reference strains) is also provided. The paper also describes the main feature of the Gurson’s model which implements the principle of limit analysis on a conceptual model of hollow sphere. The last part of the paper gives some ideas concerning poromechanical couplings.
