Aerodynamic characteristics of low aspect ratio wing equipped with Gurney flaps were studied by wind tunnel test at low Reynolds numbers of 2.0×105 and 5.0×105. Aspect ratio of the low aspect ratio wing was 1.67

with 1%-4% chord height Gurney flaps. Balance force measurements and surface pressure distribution investigation were implemented. The results suggest that lift coefficient of the low aspect ratio wing equipped with Gurney flaps was improved significantly at low Reynolds number. The lift drag ratio of wing was improved also when the wing was equipped with 1% chord height Gurney flaps. This is due to the increased lift of the wing introduced by the suitable height of the Gurney flap

while the drag has not been increased significantly at the Reynolds numbers in test. Comparing the effect of Gurney flaps with different Reynolds numbers in test

it indicates that Gurney flaps can diminish the negative effect of flow separation at low Reynolds number

and this mechanism takes more effect when the Reynolds number is lower. It requires more fine flow visualization technique to study the impact on the laminar separation phenomenon of wings with Gurney flaps at low Reynolds numbers.