Hydraulic resistance of a rod with artificial microroughness at its flowing along

Results of experimental investigation into hydraulic resistance of a rod with regularly alternating microroughness under isothermal conditions in wide regime range are given. The rod has trapezoidal form with rounded edges with r/h rounding radii, being eqUal to 0.5 at the tops and 2.0 in the bases of bulges (the height of bulges equals 0.1 mm, the width - 0.2 mm), and s/h=10 specific spacing. Obtained emprical dependences are recommended to use for hydraulic calculations of rod beams with suggested roughness form