The exhaust device of gas-driven fan propulsion system (for a VTOL aircraft) adopts vector exhaust guide vane (VEGV) to achieve vector thrust in the range of 0-90°, which requires that the deflection angle of the VEGV reach about $\pm {45}^{\circ }$ and the total pressure recovery coefficient above 0.985. Therefore, the exhaust device needs a wide-range and low-loss VEGV to ensure efficient operation of the propulsion system. And the key of this VEGV is to eliminate the separation of the suction side under large deflection angle. So, this paper designed a new type of VEGV that can meet the demands by reducing the inverse pressure gradient of the suction surface (one of the necessary conditions for two-dimensional separation). In order to realize this design process, the spectral method of small disturbance equation (SMSDE) for two-dimensional subsonic flow was developed. Then, two VEGVs were designed by the SMSDE and verified by numerical simulation with Reynolds number 10⁶ and blade solidity 1.18. The results show that the two VEGVs eliminate the separation of suction side at inlet Mach number of 0.25 and blade stagger angle of 45°. And the VEGV with lateral blade guarantees this characteristic up to Mach 0.3. Besides, when the inlet Mach number is below 0.3, the VEGV with lateral blade can ensure that the total pressure recovery coefficient is greater than 0.985, the outlet area ratio is greater than 0.95 and the exhaust angle error is less than 3.5°. Finally, Experimental verification of the vector exhaust device using the VEGV with lateral blade was carried out. The results show that the new VEGV has a higher total pressure recovery coefficient and outlet area ratio than the traditional VIGV at large deflection angles.

气驱风扇推进系统（VTOL飞机）排气装置采用矢量排气导叶（VEGV）实现0-90°范围内的矢量推力，要求VEGV的偏转角达到约 $\pm {45}^{\circ }$总压恢复系数在0.985以上。因此，排气装置需要宽范围、低损耗的VEGV来保证推进系统的高效运行。而这款VEGV的关键是消除了大偏转角下吸力侧的分离。因此，本文设计了一种新型的VEGV，通过降低吸力面的逆压力梯度（二维分离的必要条件之一）来满足需求。为了实现这一设计过程，开发了二维亚音速流动小扰动方程谱法（SMSDE）。然后，SMSDE 设计了两辆 VEGV，并通过雷诺数为 10 ^{6 的}数值模拟进行验证和刀片坚固性 1.18。结果表明，两种VEGV消除了进口马赫数为0.25、叶片交错角为45°时的吸力侧分离。带有侧向叶片的 VEGV 保证了高达 0.3 马赫的这一特性。此外，当进口马赫数在0.3以下时，带有侧向叶片的VEGV可以保证总压力恢复系数大于0.985，出口面积比大于0.95，排气角误差小于3.5°。最后，对采用横向叶片VEGV的矢量排气装置进行了实验验证。结果表明，在大偏转角下，新型VEGV比传统VIGV具有更高的总压恢复系数和出口面积比。