超临界流动不稳定性实验的通道不对称性研究

摘要

Due to the urgent need for experimental study on supercritical water flow instability , the parallel-channel asymmetry w hich determines the feasibility of such experiments was studied with the experimental and numerical results in parallel dual channel .The evolution of flow rates in the experiments was analyzed ,and the steady-state characteristics as well as transient characteristics of the system were obtained by self-developed numerical code .The results show that the asymmetry of the parallel dual channel would reduce the feasibility of experiments . The asymmetry of flow rates is aroused by geometrical asymmetry . Due to the property variation characteristics of supercritical water ,the flow rate asymmetry is enlarged while rising beyond the pseudo-critical point .The extent of flow rate asymmetry is affected by the bulk temperature and total flow rate ;therefore the experimental feasibility can be enhanced by reducing the total flow rate .%针对国内外超临界水流动不稳定性实验研究的匮乏，结合并联双通道实验研究和数值计算成果，对影响实验可行性的通道不对称性进行了分析和讨论。分析了超临界水并联双通道流动不稳定性实验中流量脉动的变化过程，并采用自编程序对系统的稳态特性和瞬态特性进行求解。结果表明：双通道流量不对称会降低实验的可行性；流量不对称性由几何结构不对称性引起；超临界水的物性变化规律导致流量不对称性在流体温度跨过拟临界的过程中被放大；流量不对称的程度受流体温度和双通道总流量影响，实验过程中可通过减小双通道总流量来提高实验的可行性。