中文摘要：

通过设置涡核模型的角度条件,使涡核模型在极限状态下仍保持收敛,进而改进了利用Biot-Savart定律计算直线涡元对空间任意一点诱导速度的模型;桨叶气动模型采用Weissinger-L升力面理论模拟;自由尾迹的求解采用PIPC松弛迭代算法结合具有二阶精度的CB2D时间步进算法.利用上述模型和算法对某型号旋翼的尾迹进行数值计算,结果显示：利用改进涡核模型计算的桨尖涡径向位移收缩更加明显,这与实际情况更加接近;利用改进涡核模型得到的自由尾迹结果与实验数据吻合的更好.上述结论可以证明,新建立的旋翼自由尾迹模型提高了原有模型的准确性.

英文摘要：

The vortex core model can keep the convergence in the limit state by setting the model angle conditions so as to improve the model of straight vortex line segment induced velocity calculated by the Biot-Savart law at every point. The model of the blade is simulated by Weissinger-L lifting-surface theory,while PIPC algorithm and CB2 D algorithm are used to solve the rotor free-wake. The models and algorithms above are then combined to numerically calculate the wake of certain rotor. The results show that the radial displacement of tip vortex calculated by the improved vortex core model contracts remarkably. This is closer to the actual situation than previous model. In addition,the result of free-wake calculated by the improved vortex core model agrees with the experimental data perfectly. Therefore,the improved free-wake model of rotor is more accurate than the original one.