Abstract
Drag reduction due to biodegradable surfactant aqueous solution was investigated in the turbulent flow range. Experiments were curried out by measuring the pressure drop of a pipe flow. Test surfactant solutions are alkylpolyglycoside solutions, which are small environmental loading. It is obtained about 40 % in the maximum drag reduction ratio of the friction factor. Drag reduction effect slightly depends on the particle size in the solution. The mechanical degradation of the drag reduction due to the alkylpolyglycoside solution did not occur in this experimental condition.
