| 摘要 |
PURPOSE:To enable the loss of pressure small and to heighten the mean heat transfer rate by a method wherein at a part of fins a plural number of raised surfaces being inclined to the air flow direction, are provided. CONSTITUTION:Flowing air generates the flows to the upward perpendicularly and along the forward surface wall. At this front, since cut-and-rises 11 is inclined with air, the turning in is generated to the back surface of the cut-and- rises 11, and the secondary flow of eddy is generated slipping off 20-30 deg. from the longitudinal direction of the cut-and-rises due to the interference of each flow. The dead water area which is generated behind the cut-and-rises is nearly disappears by this eddy. In the meantime, the loss of pressure is lowered, the separation of flow being controlled by small dense holes 13 of the lower stream side. Besides, though eddys generated by the cut-and-rise and horsesho of eddys sweeped out behind pipes disappears interfering each other, but at this time the flow of air is disturbed and the dead water area behind cupper tubes are decreased, and the heat exchanger becomes of low pressure loss and high heat transfer rate. |
