The paper is concerned with an experimental investigation of the drag reduction in turbulent channel flow over the mechanical chain. A circulating loop for the fluid flow with 0.0381 inside diameter of pipe is set up. The testing length of the system is 1.5m.Wall shear stress reduction performance has been investigated experimentally for various design geometry surfaces including a replica of bent consisting of stainless steel model scales. Attempts to optimize the net drag reduction by varying the design geometry and alignment are also discussed. The study indicated that the mechanical chain taken in water flow is capable to decrease the friction drag of a turbulent flow up to 40%. The maximum percentage was achieved in 39.37L/D at RE equal to 56733. The results show that a substantial drag reduction can be achieved by this mechanical chain in aqueous media.
Experimental investigation on friction drag reduction on an airfoil by passive blowing