Experimental and numerical investigation of the effect of angle of attack on air flow characteristics around drop-shaped tube

Abstract

The effect of angle of attack on fluid flow characteristics around a single drop-shaped tube is studied for the first time experimentally and numerically. The study covers the Reynolds numbers Re = (13.2-30.4) × 103 and flow angles of attack (θ = 0°-50° and 130°-180°). The results of the drop-shaped tube were compared with those of a circular tube having the same equivalent diameter. Numerical computational fluid dynamics modeling using the finite volume discretization method is used to predict the flow pattern around tubes. It was found that the drop-shaped tubes delay the separation of the boundary layer from the tube wall. The drop-shaped tube showed its superiority over a circular tube in terms of reduced drag and friction factor under the same operating conditions. The values of the friction factor for the arrangement of θ = 50°, 150°, and 170° are lower than those obtained for a circular tube by about 2.6-2.9, 2.6, and 2.6-3.2 times, respectively.