Interaction of second sound acoustic waves with a counterflow-induced turbulent field

The evolution of the flow and temperature fields produced by rectangular heat pulses on the background of a steady velocity and vortex line density (VLD) field is considered. This flow is described by a simplified linearised theoretical model exhibiting the dynamics of the VLD evolution. The Gorter-Mellink coefficient A is obtained from experiments on the decay of weak temperature pulses with distance from the heater. A comparison of experimental and theoretical temperature-time slopes yields a correction factor to the two growth and decay coefficients of Vinen's VLD evolution equation. (orig.)