各种两相流系统中压降的预测一直是各种研究人员大量研究的对象。该理论的大多数发展被视为与单相压降情况的处理平行，并引入了一些因素（通常通过经验获得），以修改两相应用的表达式。到目前为止，可用的理论已被用于各种系统的设计，在某些情况下，也被用于非关联式所依据的流体。各种参数（包括流量和几何形状）以复杂的方式相互作用，从而影响在两种情况下观察到的总压降- 相位系统。此外，对于存在蒸发的系统，当两相在通道中一起流动时，两相假设的各种流型进一步使预测压降的过程复杂化。这主要是因为，对于不同的流型，在获得压降估计值时，在得出流动模型时所做的假设是不同的。本研究的目的是指出现有模型在预测蒸发两相系统压降方面的一些局限性，并提出可能有助于改进现有预测方案的建议。 引文:研讨会，ASHRAE交易，第86卷，第2部分，科罗拉多州丹佛

The prediction of the pressure drop in various two-phase flow systems has been the object of numerous studies by various investigators.Most developments of the theory are seen to parallel the treatment for the single-phase pressure drop case with some factor, usually obtained empirically, being introduced to modify the expressions for two-phase applications. The available theory has been used, so far, in the design of various systems and, in some cases, for fluids other than those upon which the correlations have been based. Various parameters (both flow and geometry) interact in complex ways to affect the overall pressure drop observed in a two-phase system. Besides, for a system in which there is evaporation, the various flow regimes assumed by the two phases as they flow together in the channel further complicate the process of predicting the pressure drop. This is mainly because the assumptions made in arriving at the flow models in obtaining the pressure drop estimates are different for different flow regimes.It is the purpose of this study to point out some of the limitations of existing models for predicting the pressure drop in an evaporative two-phase system and to offer suggestions that might prove useful in the improvement of the existing prediction schemes.