主催: 一般社団法人 日本機械学会
会議名: 第94期流体工学部門講演会
開催日: 2016/11/12 - 2016/11/13
An interesting phenomenon about irreversible viscosity in the large amplitude oscillatory shear, LAOS, of the wormlike micellar solutions is found. A wormlike micellar solution exhibits a different viscosity in the CW direction compared with one in the CCW direction in each period of the LAOS flow. This phenomenon appears only when a suitable preshear is applied before the LAOS flow. The difference of the shear stress between the CW direction and the CCW direction at a several periods from the onset of the LAOS is very large and it is named the transient irreversibility. In some condition, the irreversibility keeps permanently. It is named the permanent irreversibility. The transient irreversibility becomes large in a certain shear rate in the pre-shear, but the permanent irreversibility is not affected by the shear rate of the pre-shear.