抄録
Small-sized axial fan is used as air cooler for electric equipments. But there is demand for higher power of fan according to the increase of quantity of heat from electric device. Therefore, higher rotational speed design is necessary but it causes the deterioration of efficiency and increases the noise. Contra-rotating axial fan is smaller than single axial fan under the same rotational speed, and is effective against lower rotational speed design under the same diameter. In addition, contra-rotating small-sized axial fan is higher efficiency compared with single small-sized axial fan. Then the adoption of contra-rotating rotor for small-sized fan was proposed for the improvement of performance. In the present paper, experiment was conducted to investigate the effect on performance by changing the axial distance between front and rear rotors of contra-rotating small-sized axial fan. And the relationship between the performance and axial distance between front and rear rotors was clarified with the experimental results.
