A robust methodology to develop phase diagrams of binary fluid mixtures at fixed thermodynamic conditions (pressure, temperature, and mole fraction) as well as of two initially separated fluids undergoing mixing near critical conditions are presented for fluids and conditions relevant to rockets, gas turbines, and diesel engine applications. Phase equilibria of mixtures are first examined to provide insight into the continuous-phase mixing behavior (including but not limited to supercritical behavior), and to develop a broadly applicable phase-diagram for binary fluid mixtures at fixed conditions. Next, adiabatic mixing theory and reduced Helmholtz equations of state are used to predict the thermodynamic conditions required to attain continuous-phase binary fluid mixing near critical conditions. Then, a 3D surface diagram ($P$, $T_{fuel}$, $T_{amb}$) separating single and two-phase regions is constructed by varying the ambient pressure and the initial temperatures of the two fluids. Polynomial fits of the 3D surfaces for 10 different binary mixtures are tabulated for nitrogen–alkane and methane–oxygen blends relevant to air-breathing and propellant based engines, respectively.

针对与火箭、燃气轮机、和柴油发动机应用。首先检查混合物的相平衡，以深入了解连续相混合行为（包括但不限于超临界行为），并为固定条件下的二元流体混合物开发广泛适用的相图。接下来，绝热混合理论和简化的 Helmholtz 状态方程用于预测在临界条件下实现连续相二元流体混合所需的热力学条件。然后，一个3D表面图（$P$,${吨}_{F你\mathrm{电子}升}$,${吨}_{A米b}$) 分离单相和两相区域是通过改变环境压力和两种流体的初始温度来构建的。表中列出了 10 种不同二元混合物的 3D 表面的多项式拟合，分别用于与吸气式发动机和基于推进剂的发动机相关的氮-烷烃和甲烷-氧混合物。