摘要
采用有限元数值模拟的方法计算混凝土内置冷却水管的对流系数,得到了冷却水管各截面平均努赛尔数沿管长的变化曲线。结果表明:弯曲位置流场分布复杂,截面出现明显的二次流,减小了冷却水沿管程的主流速度,阻碍流动传输。努赛尔数在直管和弯管结合部位变化剧烈,沿弯曲路径逐渐降低,最大变化幅度达20%,降低了冷却水与周围混凝土的换热效率。分析表明采用近似法计算混凝土温度场时应分段施加对流换热系数,保证求解精度。
A finite element method was developed to simulate the convective coefficient of cooling water pipe in concrete,and the mean Nusselt numbers on each section in the cooling water pipe were obtained.Numerical results show that the flow field distribution was very complex with a secondary flow appeared in the bend position.The cooling water flow velocity decreased along the pipeline accompanying the secondary flow,it was not advantageous for promoting heat transfer.Nusselt number changed greatly at the joint of straight part with bend section,which decreased gradually along the pipeline with the maximum value change rate of 20%,leading to the decrease of heat transfer between the cooling water and the concrete.It suggested that the Nusselt convective coefficient should be piecewise loaded to ensure the accuracy of results,when employ an approximate method to calculate the temperature field.
出处
《混凝土》
CAS
CSCD
北大核心
2010年第12期118-120,共3页
Concrete
基金
科技部地震行业专项基金资助项目(200808021)
防灾减灾青年科技基金(201002)
关键词
有限元
混凝土
冷却水
对流系数
finite element
concrete
cooling water
convective coefficient
