| 摘要 |
PURPOSE:To improve fan efficiency by specifying the outside diameter and the flow coefficient of a fan where fluid inside a heat exchanger such as a radiator is cooled after flow of cooling air produced with the fan is rectified by a fan shroud. CONSTITUTION:A radiator 1 consists of a radiator core 7, upper and lower tanks 5, 10, tubes 8 between both the tanks 5, 10 and air fins 9. Behind such a radiator 1, provided is a fan 2 which is mounted through a fan shroud 4 serving as flow-rectifying device for cooling-air flow A. Where such a cooling device is provided, the outside diameter D of the fan 2 is to be 280-360mm. and the flow coefficient is to meet a value between 0.08 and 0.21 from: phi=Vad/[piD<2>/ 4.(piDN/60)X3,600]Where N(rpm)=a number of revolutions of the fan 2 Vad (m<3>/h)= air volume at the maximum efficiency from this, the maximum fan efficiency can be obtained. |
