Showing papers by "S.V. Prabhu published in 2003"

Effect of Guide Vanes on Pressure Drop in a Rib Roughened Square Channel with a Sharp Cornered 180 Deg Bend

Abstract: An experimental investigation is carried out to study the effect of several turn treatments like single guide vane (short and long) and multiple guide vanes on the pressure drop distribution in a square cross sectioned rib roughened channel with a sharp 180 0 bend. The sharp 180 0 turn is obtained by dividing a rectangular passage into two square channels using a divider wall with a rounded tip at the location where the flow negotiates the turn. The ribs are configured in a symmetric arrangement with an angle of 90 0 to the main-stream flow with ribbed surfaces forming the top and bottom surfaces. The rib height-to-hydraulic diameter ratio (e/D) was maintained constant at 0.14 with a constant pitch-to-rib height ratio (P/e) of 10. The study is carried out for a divider wall thickness to hydraulic diameter (W/D) of 0.21 for Reynolds numbers of 12000, 14250 and 16500. The pressure drop distribution normalized with the mainstream fluid dynamic pressure head is presented for the outer surfaces. The results indicate that the shape and position of the guide vanes significantly affect the pressure losses associated with coolant flows through sharp 180 0 bend. Properly shaped 180 0 extended guide vanes located in the center of the bend decrease the overall pressure drop by as much as 14-20% compared to the no guide vane within the bend.