Aimed at the disadvantage of pressure loss which exists in the vane air flow sensor

by analyzing the flow state in the pipe

it is found that the main reason of pressure loss is the too large area of wing-rib.Decreasing the wing-rib area to 20 % of original area

the rotating torqueses are calculated with the different shapes

for example

circular

fan

bow and partial circular ring.The results show that the wing-rib with bow shape has the biggest rotating torque with the same pressure loss among the 4 kinds of wing shapes

and the torque can meet the measuring acquirement in the idle state.The results also can be useful in the design of the new style vane air flow sensor.