矩形渦発生体の傾斜角度, 迎え角度, 及び配列が伝熱性能に及ぼす影響

抄録

We have studied the enhancement of heat transfer by vortex generators. Experimental test was done on rectangular-type vortex generators which were mounted on a parallel-plate heater. Heat transfer coefficient of the heater surface and the pressure drop in the duct were measured. These measurements indicated that a rectangular-vortex generator (called double-inclined winglet) with the inclination angle of the vortex generator surface to the heater surface (β) at 60 degrees and the attack angle to the flow direction (γ) at 45 degrees maximizes local Nusselt number of the heater surface. It was also found that the double-inclined winglet has an optimal arrangement in the winglet array, longitudinal pitch and transverse pitch, that maximizes the ratio [Colburn's heat transfer modulus j_H]/ [friction factor f]. Numerical calculation result showed that the double-inclined winglet was superior to the conventional rectangular vortex generator in heat transfer.