Experiments were conducted to study the drag-reduction characteristics of a newly synthesized zwitterionic surfactant solution (oleyl trimethylaminimide) in a two-dimensional channel.Ethylene glycol aqueous solution (EG/W) with mass fraction of 20% was used as solvent for measurements at subzero temperatures.The surfactant mass concentration ranged from 5×10-5 to 1×10-3

and the temperature was -5℃ and 25℃ respectively.Turbulence features of the surfactant drag-reducing flow were also measured by using particle image velocimetry (PIV) technique.It was found that the novel zwitterionic surfactant solution showed drag-reduction characteristics which were greatly affected by both concentration and temperature.The maximum drag-reduction could reach 83%.The addition of NaNO2 to the novel surfactant solution could improve the drag-reduction performance at low temperatures and concentrations

whereas it had a negative effect at high temperatures and concentrations.Turbulent velocity and vortex fluctuations were suppressed and Reynolds shear stress was diminished by adding surfactants into the turbulent flow.