基于FLUENT的核电用文丘里管稳流性能研究

采用Realizable k-?湍流模型和Zwart空化模型对某核电用空化型文丘里管的空化流动进行了数值模拟。模拟在特定工况条件下文丘里管内流动情况，得到流量变化曲线，预测空化区域，分析稳流原理和规律。模拟不同喉部直径文丘里管稳流性能，探究喉部直径变化对空化的影响。研究结果表明:随着入口压力的增大，文丘里管将发生空化塞流。将流量变化控制在一定范围内，达到相对稳流的作用。稳流时，管路压力每升高0.1 MPa，流量增加0.06 m3·h-1；喉部直径的尺寸直接影响水力空化初生与流量增幅；在一定范围内，文丘里管喉部直径大，空化流动发展迅速且流量增幅大，喉部直径小，管路流量增长幅值小。 

Numerical Simulation on Flow Control Performance of Nuclear Venturi Tube Based on FLUENT

The cavitatingflow occurred in a nuclear power venturi tube was numerically simulated based on Realizable k-? turbulence model and Zwart (Zwart-Gerber-Belamri) cavitation model. The flow rate curves and properties inside venturi tube was analyzed and cavitation area was predicted effectively under the operated condition. The steady flow rules of the given venturi tube were studied according to the CFD simulation results. It can be concluded that: the choke flow happened in the venturi tube with the inlet pressure increasing; the flow rate changes in venturi tube could be controlled in a certain range with the flow rate increase of 0.06 m3·h-1 with the inlet pressure increasing 0.1 MPa; throat diameter determines the cavitation inception and the increment of flow rate directly; the larger throat diameter causes the faster and higher development degree of the? cavitating flow, meanwhile, the increasing of flow rate in the tube is slower with small throat diameter.