摘要
研究的两流体不平衡模型，用来计算初始滞止状态为饱和或过冷流体通过通道的临界流量，模型中既考虑了两相之间的动力学不平衡，也考虑了相间热力学不平衡──温度差异。引入汽泡运动弛豫时间方程，结合两相质量守恒方程，动量守恒方程组成五方程模型。通过解汽泡在无限大介质中边界层非稳态导热问题，获得界面热负荷，井利用两相混合物能量方程，获得液相过热度，从而计算出蒸发速率。引用合适的经验关系式，计算界面摩擦切应力，壁面摩擦切应力。提出厂圆弧入口和直段入口两类边界条件的处理方法，设置异质汽核密度为可调参数，当其值取为２．５×ｌ０１１时，在较阔的压力范围内，对不同的长径比Ｌ／Ｄ，预测结果和实验值符合较好。
The non-equmbrium two-fluid model presented in this paper has been used to calculate the critical mass flux of initially saturated or subccoled water discharging from channel.Both inter-phase relative motion and interphase thermal non-equilibrium are all considered in this model.The bubble moving conservation equation constitutes a five-equation model.The interphase heat flux is obtained by solving the boundary unsteady-state heat conduction problem,and the liquid superheat temperature is acquired by sOlving the two-phase mixture energy equation,then the steam evaporation rate is obtained.Some empirics are introduced to calculate the interphase shear stress and wall shear stress.The method of treating the curved inlet and sharp-edged inlet boundary is presented,and the bubble number density is considered to be the adjustable parameter.Predictions compare favorably with experimental data over a wide range of pressures and for different pipe length/pipe diameter ratio as the bubble number density being adjusted to be 2.5×l011/m
出处
《核科学与工程》
CAS
CSCD
北大核心
1995年第1期16-26,共11页
Nuclear Science and Engineering
基金
国家自然科学基金
国家核安全局资助项目
关键词
临界流
两流体模型
相间不平衡
critical flow two-fluid model interphase non-equilibrium
