The results in Fig nbsp a nbsp
The streamwise velocity variation along the tube axis and near (r/R = ±0.7, r AGN 205327 radial distance from the axis, R is internal radius of the tube) inner, outer, top, bottom wall is plotted in Fig. 7a. The velocity is normalized with the sonic speed and the axial distance is normalized with the length of the test section after the tube has been unfolded. The sudden drop in the centerline velocity and the streamwise velocity along the outer and top/bottom wall near the bend is noticed from the figure. However, the streamwise velocity near the inner wall (r/R = +0.7) sharply increases near the bend. The slip velocity at the inner, outer and top/bottom walls is shown in Fig. 7b. The maximum slip occurs at the inner wall corner (X/L = 0.5) while the minimum slip occurs at the outer wall corner. An intermediate value of the slip velocity is noted at the top/bottom walls in the vicinity of the bend. Notice endothermic the trend reverses after the bend. These different flow behaviors indicate the complexity of the flow near the bend plane (the region is divided in three zones, Fig. 7) for the purpose of analysis in the next section.