CAJ | 학술논문

射流放水阀是水电站和水坝放水系统中广泛应用的流量控制装置.目前关于射流放水阀的数值模拟均为静止状态下的流场分析,运动状态下的流场数值模拟还未见报道.本文采用温度体模型和重叠分区背景网格方法生成射流阀动态关闭过程中的计算域网格,首次采用数值模拟方式对其动态过程进行研究.数值模拟结果显示,射流阀流量与开度呈近似线性变化规律,但在大开度和小开度范围内,流量随开度的变化较为平缓.水流经阀针后发生分离,在其背部形成主流区、剪切层区和回流区.在阀针外缘处、阀壳喉部及阀针后侧的压力远远低于阀针头部及正面压力,将导致这些区域发生汽蚀.数值模拟结果与实验观测到的现象非常吻合.
사류방수벌시수전참화수패방수계통중엄범응용적류량공제장치.목전관우사류방수벌적수치모의균위정지상태하적류장분석,운동상태하적류장수치모의환미견보도.본문채용온도체모형화중첩분구배경망격방법생성사류벌동태관폐과정중적계산역망격,수차채용수치모의방식대기동태과정진행연구.수치모의결과현시,사류벌류량여개도정근사선성변화규률,단재대개도화소개도범위내,류량수개도적변화교위평완.수류경벌침후발생분리,재기배부형성주류구、전절층구화회류구.재벌침외연처、벌각후부급벌침후측적압력원원저우벌침두부급정면압력,장도치저사구역발생기식.수치모의결과여실험관측도적현상비상문합.
Hollow-jet valve is widely used in water discharging system of hydropower station and dam. At present, the computational fluid dynamics of hollow-jet valve is under the static analysis. In this thesis, grids' reference temperature distribution and division of background grid are used to generate the dynamic grid during the closing process. The computational fluid dynamics obtain the flow rates at different valve opening. The pressure at the outer margin and backside of valve needle, throat of valve shell is much lower than front side, which will case the vortex cavitation. This result is highly identical with the phenomenon observed by experimental methods.