Patent ID: 7337831

Claim:
A heat transfer device having linear or tubular heat transfer objects which are in heat transfer contact with a heat carrier fluid, and heat transfer fins which are integrally formed with the heat transfer object for heat transmission therebetween, the heat transfer object having a circular cross-section, comprising: a pair of guide fins positioned on both sides of said heat transfer object in the vicinity of the heat transfer object, the guide fins being configured for delaying a position of separation of the heat carrier fluid, an upstream end of the guide fin being located on an upstream side of a center of the heat transfer object, a downstream end of the guide fin being located on a downstream side of the center, each of said guide fins having an upper edge in the form of a straight line or curved line gradually increasing in height in a direction of flow of said heat carrier fluid for generating a longitudinal vortex behind the guide fin, each of the guide fins having a base on a plane of said heat transfer fin and being oriented at an attack angle α in a range from 10° to 60° relative to the direction of flow of said fluid to define a fluid passage for the heat carrier fluid between the guide fin and the heat transfer object, the passage diverging toward an upstream side of the heat transfer object and converging toward a downstream side of the heat transfer object, an altitude (h) at a highest part of the guide fin being dimensionally set to be equal to or greater than one half of an interval (Pf) of said heat transfer fins, a length (L) of said base being greater than a radius (R) of the heat transfer object, a ratio of the length (L) the base to the altitude (h) at a highest part of the guide fin being set to be in a range from 2 to 7, the downstream end of the guide fin being spaced from the heat transfer object to form a narrow gap for spouting the heat carrier fluid therethrough, so that said fluid entering an area between said heat transfer objects is accelerated between the heat transfer object and said guide fin and conducted to the rear of said heat transfer object for reducing a separation wake zone behind said heat transfer object and generating, behind the guide fin, a swirl flow deflected in accordance with an obliquity of said guide fin.