The orifice angle has great impact on the internal flow and discharge coefficient characteristics of oil jet nozzles. This paper presents numerical research on the internal flow and discharge coefficient behaviors of oil jet nozzles with different orifice angles. For this purpose, oil jet nozzles with different orifice angles in the range from $0^{\circ }$ to ${90}^{\circ }$ were evaluated under real injection pressure difference conditions ($0.10\sim 0.50$ MPa). The main results show that the mass flow rate, discharge coefficient and velocity coefficient decrease first and then increase with the increasing orifice angle. The value of each parameter corresponding to the orifice angle of ${90}^{\circ }$ is slightly higher than that of $0^{\circ }$. The minimum value is obtained with the orifice angle of ${30}^{\circ }$, and the relative deviation between the highest and the lowest mass flow rate exceeds 11.5%. On this basis, the prediction formula of angle coefficient with extremely high goodness of fit is obtained by using polynomial fitting method for the multiple groups of normalized discharge coefficients, and the corrected empirical correlation of discharge coefficient and mass flow rate are developed in the light of the angle coefficient. Comparing the corrected empirical correlation prediction results with the numerical simulation results, the maximum deviation of the mass flow rate is 1.9%.

孔角对喷油嘴的内部流量和排放系数特性有很大影响。本文对不同节流孔角的喷油嘴的内部流动和排放系数特性进行了数值研究。为此，具有不同孔角的喷油嘴的范围在$0^{\circ }$ 至 ${90}^{\circ }$ 在实际喷射压力差条件下进行评估（$0.10〜0.50$MPa）。主要结果表明，随着节流孔角度的增加，质量流量，流量系数和速度系数先减小后增大。每个参数的值对应于孔口角度${90}^{\circ }$ 略高于 $0^{\circ }$。最小值是通过孔口角为${30}^{\circ }$，最高和最低质量流量之间的相对偏差超过11.5％。在此基础上，采用多项式拟合方法对多组归一化的排放系数进行拟合，得到了角度系数的拟合度极高的预测公式，并针对排放系数与质量流量的经验关系式进行了修正。角度系数。将校正后的经验相关性预测结果与数值模拟结果进行比较，质量流量的最大偏差为1.9％。