Effect of Agar Jelly Coating in Rectangular Pipe to Flow Drag Reduction


1 Department of Mechanical Engineering, University of Indonesia, Jakarta 16424

2 Department of Mechanical Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo 192-0397, Japan


Drag reduction phenomena can be obtained using additive polymer that can generate turbulence damping by fluid movement and characteristic. Measurements were carried out to investigate pressure losses in square and rectangular horizontal ducts coating of additive Agar solution, with aspect ratios (e) = 1.0 and 0.5, respectively. The increment concentrations are ranged up to 2 times and drag reduction effect was obtained up to 1.5 times bigger. This research analysis was done using friction coefficients and Reynolds numbers relation to put forward drag reduction phenomena. The effect of Agar coating delayed the transition regime. The research results using 1 mm of thickness Agar coating with concentration 20% and 40% concentrations were obtained maximum drag reduction phenomena about 19% at the Reynolds number about 2,600.