This study examines the heat transfer enhancement from a horizontal rectangular fin embedded with triangular perforations （their bases parallel and toward the fin tip） under natural convection. The fin＇s heat dissi...This study examines the heat transfer enhancement from a horizontal rectangular fin embedded with triangular perforations （their bases parallel and toward the fin tip） under natural convection. The fin＇s heat dissipation rate is compared to that of an equivalent solid one. The parameters considered are geometrical dimensions and thermal properties of the fin and the perforations. The gain in the heat transfer enhancement and the fin weight reduction due to the perforations are considered. The study shows that the heat dissipation from the perforated fin for a certain range of triangular perforation dimensions and spaces between perforations result in improvement in the heat transfer over the equivalent solid fin. The heat transfer enhancement of the perforated fin increases as the fin thermal conductivity and its thickness are increased.展开更多
The triangwlar fibrocartilages(TFC) of 136 wrist joints from 48 fetuses and 20 infants fresh cadavers without any evidence of known deformity and injary were studied .Perforations of the TFC were found not only in inf...The triangwlar fibrocartilages(TFC) of 136 wrist joints from 48 fetuses and 20 infants fresh cadavers without any evidence of known deformity and injary were studied .Perforations of the TFC were found not only in infants(18.8%),but also in fetuses(25%).展开更多
文摘This study examines the heat transfer enhancement from a horizontal rectangular fin embedded with triangular perforations （their bases parallel and toward the fin tip） under natural convection. The fin＇s heat dissipation rate is compared to that of an equivalent solid one. The parameters considered are geometrical dimensions and thermal properties of the fin and the perforations. The gain in the heat transfer enhancement and the fin weight reduction due to the perforations are considered. The study shows that the heat dissipation from the perforated fin for a certain range of triangular perforation dimensions and spaces between perforations result in improvement in the heat transfer over the equivalent solid fin. The heat transfer enhancement of the perforated fin increases as the fin thermal conductivity and its thickness are increased.
文摘The triangwlar fibrocartilages(TFC) of 136 wrist joints from 48 fetuses and 20 infants fresh cadavers without any evidence of known deformity and injary were studied .Perforations of the TFC were found not only in infants(18.8%),but also in fetuses(25%).
