Specific power input and local micromixing times in turbulent Taylor-Couette flow

In the present work, the distribution of the local dissipation rate of turbulent kinetic energy in Taylor-Couette flow was studied with the help of the particle image velocimetry (PIV). The experimental values of dissipation rate are strongly affected by spatial resolution of PIV measurements. Therefore, a reference value of the average specific power input is needed. Such a value was achieved from an independent torque measurement. Using these values it was possible to quantify the true local values of the dissipation rate. The distribution of mixing times in the gap could thus be calculated and was found to become more homogeneous with increasing turbulence intensity.