Drag reduction and degradation characteristics of nata de coco suspension in spiral pipe

Recently, the research of energy efficiency in some areas is an important topic to be developed. In fluid flow, some techniques are developed in order to decrease the pressure drop. Therefore, some researchers add several kinds of additives in order to obtain drag reduction. The purpose of this research is to investigate the effect of nata de coco fiber suspension due to the drag reduction characteristic in the spiral pipe. The experiment was conducted from low-to high-Reynolds number, up to 20,000. 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 nata de coco fiber suspension into water can reduce drag either on circular pipe or spiral pipe. The maximum drag reduction of concentration 60 ppm for spiral pipe is about 24.7%, and for circular pipe is about 22.1%, at a Reynolds number of about 19,000. It was observed that the drag reduction tended to be constant, with an increase in concentration after 60 ppm. The nata de coco 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. Further, the nata de coco fiber suspension is good for the mechanical degradation effect. Based on this research, it can be concluded that nata de coco can be considered as a drag reducing agent.