Drag reduction characteristic of seaweed fiber solution in round and spiral pipe

Energy efficiency has attracted interest of researchers. One of the attracting researches is about drag reduction in pipe by adding drag reducing agent into the fluids. Experimental research of the effects of drag-reducing bio-fiber in a spiral pipe was carried out. The aim of this research was to investigate drag reduction in spiral pipe with addition seaweed fiber solution into water. Seaweed fiber solution was prepared in concentration 20, 50, and 100 ppm and circulated by pump into spiral pipe P/Do 7.6 and round pipe ID 38 mm as comparison. Experimental was conducted from low to high Reynolds number up to 35,000. The percentage of drag reduction was calculated using the obtained experimental data, in presence of the drag reducing agent. The results showed that the addition of seaweed fiber solution into water can reduce drag either on round pipe or spiral pipe. The maximum drag reduction of concentration 100 ppm for round pipe is about 16% and for spiral pipe is about 20% at Reynolds number about 35,000. It was observed that the drag reduction increased with increasing of concentration. The seaweed fiber solution tends to spread and flow straightly at the center of the experimental pipe and a water layer develops at the wall. It reduces the wall friction and reaches the maximum drag reduction. It is believed that friction coefficient decrease on buffer layer of pipe. Based on this research, it can be concluded that seaweed fiber can be considered as drag reducing agent.