Unsteady numerical simulation was conducted to study distributed propeller slipstream problem of solar unmanned aerial vehicle based on structured/unstructured hybrid grid CFD methods. Wing was segmented to eliminate the influence of finite span three-dimensional effects and simplify the research object

and the sliding mesh and transition model were applied in the numerical simulation; then the conditions of propeller in front of or behind the wing were discussed and compared with pure wing and pure propeller. The result shows that propeller in front of or behind the wing makes wing lift

drag and nose-down pitching moment increase and fluctuate periodically

while propeller behind the wing has less impact on the wing. The wing causes propeller thrust

absorbed power and efficiency increase and fluctuate periodically

while non-uniformity of flow field results in vibration of peopeller.