Studies(experimental study,theoretical analysis,numerical simulation and application tests in real systems)over around a half century since its discovery have provided much understanding on the turbulent drag reduction phenomenon and its value in applications.

To clarify the relation between turbulent drag reduction and self-excited vibration of flexible tubes, experiments were performed on the effects of turbulent drag reduction and the characters of self-excited vibration, by comparing the turbulent drag with, that in a rigid tube and by using a double-sleeve structure and a laser displacement sensor.

Since then, turbulent drag reduction techniques have been more and more applied in engineering equipment of convection heat transfer.

Since Toms found the turbulence drag reduction induced by the polymer,a lot of investigations have been done on the subject,but the mechanism for the drag reduction by the polymers still remains under debate.

Heating transfer enhancement to surfactant drag-reducing fluid with mesh-screen in the duct;

The results indicate that the heat transfer reduction rate of the CTAC drag-reducing fluid increases with Reynolds number when Reynolds number is below the critical value and decreases rapidly when Reynolds number exceeds the critical value,the trends of heat transfer .

The effect of concentration,mixture ratio,Reynolds number and heat flux of CTAC surfactant drag-reducing fluid has been investigated in a two-dimensional channel by using pressure difference transducer and temperature measuring system.

Based on the confirmation of the turbulent drag reduction effect of flexible tubes,an experimental study was conducted on the drag reduction effect by self-excited vibration of flexible tubes with a double-sleeve structure.

Based on there existing the effect of turbulent drag reduction in flexible tubes examined by experiment, the experimental investigation was performed on effect of turbulent drag reduction and character of flow-excited vibration.