平行回転する円筒内の熱伝達

概要

論文の詳細を見る
In the purpose of investigating heat transfer characteristics in a parallel rotating cylinder, experiments had been carried out. The parallel rotating cylinders are applied to the ducts of turbine blade of jet engine, the ducts at disk rotor of brake system etc.The test cylinder was made of copper tube (O.D. 22.0 mm, I.D. 20.0mm, length of 20.0 mm). The outer side of the cylinder was heated by coiled Nichrome wire. Moreover, the outer side of heating section was insulated by calcined Calcium Sulfate and Bakelite. Also, the edges of cylinder were insulated by Bakelite. So,the heat was transferred only to the inner side of the cylinder. The cylinder was fixed with a rotating disc. To find out the temperature distribution, two types of tests had been carried out. First, five thermocouples were fixed in the radial direction. Next, five thermocouples were fixed in the axial direction. Power supply to the Nichrome wire and electric signal from thermocouples were transmitted by slip rings.The results were obtained as follows.In the radial direction, maximum air temperature was obtained at the furthest position from rotating center.In the axial direction, maximum air temperature was obtained at the middle position in the cylinder.The temperature differences between the heating surface and the room temperature were decreased by increasing the revolutions per minute. Also, the heat transfer coefficients were increased by increasing the revolutions per minute.