MEASUREMENT OF EDDY DIFFUSIVITY OF HEAT IN SODIUM
Measurements have been made of the eddy diffusivity of heat in a circular pipe with turbulent sodium flow. For this type of experiment a new technique has been used, in which a source of heat is injected into the central region of the pipe. From measurements of the temperature
distribution in the sodium flow downstream of the injector position, the total effective thermal diffusivity is evaluated. At a Reynolds number of 8 × 104 the eddy contribution to the total thermal diffusivity was
found to be such that ∈H/α varied between 0.7 and 0.8.