The quenching of a metal component with a channel section in a water tank is numerically simulated.Computational fluid dynamics (CFD) is used to model the multiphase flow and the heat transfer in film boiling,nucleate...The quenching of a metal component with a channel section in a water tank is numerically simulated.Computational fluid dynamics (CFD) is used to model the multiphase flow and the heat transfer in film boiling,nucleate boiling and convective cooling processes to calculate the difference in heat transfer rate around the component and then combining with the thermal simulation and structure analysis of the component to study the effect of heat transfer rate on the distortion of the U-channel component.A model is also established to calculate the residual stress produced by quenching.The coupling fluid-thermal-structural simulation provides an insight into the deformation of the component and can be used to perform parameter analysis to reduce the distortion of the component.展开更多
Equipped with its Solver and-in and VBA, Microsoft Excel makes an ideal educational platform for design analyses of fluid-thermal systems. This paper illustrates this capability by considering a common type of these s...Equipped with its Solver and-in and VBA, Microsoft Excel makes an ideal educational platform for design analyses of fluid-thermal systems. This paper illustrates this capability by considering a common type of these systems;which is the double-pipe heat exchanger. While Solver is used for the optimisation analysis, VBA is used for the development of a user-defined function (UDF) that determines the optimum standard-pipe size for the system.展开更多
反应堆一回路中部分管道长期承受冷热流体的交替冲刷,局部可能出现的热分层现象使管道中的热应力进一步加大,由此产生的应力集中及疲劳问题可能危害反应堆的安全运行。基于热流固多物理场耦合方法结合ASME(American Society of Mechanic...反应堆一回路中部分管道长期承受冷热流体的交替冲刷,局部可能出现的热分层现象使管道中的热应力进一步加大,由此产生的应力集中及疲劳问题可能危害反应堆的安全运行。基于热流固多物理场耦合方法结合ASME(American Society of Mechanical Engineers)规范中适用于核一级承压设备的相关标准和分析流程,对某型号反应堆的管道系统开展了结构强度校核及疲劳分析,数值结果表明:当前工况参数及出现次数叠加作用下管道系统的应力分类结果满足规范要求,不会出现不可逆的结构损伤,且关键结构不连续位置的疲劳累积使用因子均小于1,未出现累积使用因子超限问题。展开更多
文摘The quenching of a metal component with a channel section in a water tank is numerically simulated.Computational fluid dynamics (CFD) is used to model the multiphase flow and the heat transfer in film boiling,nucleate boiling and convective cooling processes to calculate the difference in heat transfer rate around the component and then combining with the thermal simulation and structure analysis of the component to study the effect of heat transfer rate on the distortion of the U-channel component.A model is also established to calculate the residual stress produced by quenching.The coupling fluid-thermal-structural simulation provides an insight into the deformation of the component and can be used to perform parameter analysis to reduce the distortion of the component.
文摘Equipped with its Solver and-in and VBA, Microsoft Excel makes an ideal educational platform for design analyses of fluid-thermal systems. This paper illustrates this capability by considering a common type of these systems;which is the double-pipe heat exchanger. While Solver is used for the optimisation analysis, VBA is used for the development of a user-defined function (UDF) that determines the optimum standard-pipe size for the system.
文摘为了探究玻璃成型预加热段中部凹陷的形成机理及玻璃厚度、长宽比两种形状参数对其影响,基于生产线预加热炉的工艺流程,建立了流体-热场-固体多物理场耦合数值模型.同时,利用高温红外热成像技术获取预加热段结束时玻璃表面的温度场分布情况,以验证炉腔内流体-热场耦合数值模型的准确性.然后基于流体-热场-固体多物理场模型对预加热段玻璃中部凹陷形成过程进行仿真,探究玻璃中部凹陷形成的机理.最后探讨了两种形状参数对玻璃凹陷变形的影响程度.研究表明:玻璃的形状参数对玻璃的形变有重要影响,即随玻璃厚度减小,弯曲刚度也不断减小,玻璃中部凹陷越严重;玻璃的长宽比对玻璃变形也有重要影响,当玻璃长宽比从6.32减小到1.58时,玻璃的横向热应变区会增大,玻璃的凹陷深度从4.65 mm增加到9.34 mm.
文摘反应堆一回路中部分管道长期承受冷热流体的交替冲刷,局部可能出现的热分层现象使管道中的热应力进一步加大,由此产生的应力集中及疲劳问题可能危害反应堆的安全运行。基于热流固多物理场耦合方法结合ASME(American Society of Mechanical Engineers)规范中适用于核一级承压设备的相关标准和分析流程,对某型号反应堆的管道系统开展了结构强度校核及疲劳分析,数值结果表明:当前工况参数及出现次数叠加作用下管道系统的应力分类结果满足规范要求,不会出现不可逆的结构损伤,且关键结构不连续位置的疲劳累积使用因子均小于1,未出现累积使用因子超限问题。
