Effect of Turn Region Treatments on the Pressure Loss Distribution in a Smooth Square Channel with Sharp 180° Bend

[摘要] An experimental investigation is carried out to study theeffect of several turn treatments like single guide vane (shortand long) and multiple guide vanes on the pressure drop distributionin a square cross-sectioned smooth channel with asharp 180° bend. The sharp 180° turn is obtained by dividinga rectangular passage into two square channels using adivider wall with a rounded tip at the location where theflow negotiates the turn. The study is carried out for a dividerwall thickness to hydraulic diameter(W/D)of 0.2 for Reynolds numbers of 13,500 and 17,000. The pressure drop distribution normalized with the mainstream fluid dynamicpressure head is presented for the outer surfaces. The resultsindicate that the shape and position of the guide vanes significantly affect the pressure losses associated with coolant flows through a sharp 180° bend. Properly shaped 180° vanes located in the center of the bend decrease the overall pressuredrop by as much as 40–45% compared to the no guide vanewithin the bend.

[学科分类] 力学，机械学