Fluid transport tube

PROBLEM TO BE SOLVED: To provide a fluid transport pipe having a pipe shape such that a flow passage cross-sectional area is enlarged or reduced regularly in the forward direction of a fluid, and capable of ensuring the greater resistance reduction effect.SOLUTION: First unit flow passages 12a the cross-sectional area of which is continuously reduced downward and second unit flow passages 12b the cross-sectional area of which is continuously enlarged downward are alternately combined. A ratio A(=L/((Smax)-(Smin))) is set to fall in a range where a resistance reduction rate Rhas a positive value. A fluid transport pipe comprises: a first slit 22a that is formed in a flow passage wall of each first unit flow passage 12a in a region located radially inward of an inner wall of a maximum area portion 16; a second slit 22b that is formed in a flow passage wall of each second unit flow passage 12b in the region located radially inward of the inner wall of the maximum area portion 16; and a bypass flow passage 20 that bypasses a flow in the direction from each first unit flow passage 12a to each second unit flow passage 12b while being interposed between the slits 22a, 22b.SELECTED DRAWING: Figure 1