Diffusion turbulente dans le sillage d'un fil

Ingénieur à la Direction des Etudes et Recherches, E.D.F., Chatou.

Résumé

The turbulent heat transfer process involved in the simple case of heat diffusion in the wake of a hot wire stretched diametrically across a tube cross-section is investigated for flow Reynolds numbers of 270,000 and 560,000. The resistance thermometer specially designed for the purpose had a 4 m dia. X 0.5 millimetre long platinum wire for its sensitive element and was capable of measuring temperature differences to within 1/200 °C. The notion of a turbulent heat diffusivity coefficient is discussed in the light of the results obtained and is found to show the general properties of turbulent flow as it cannot be related to the local flow characteristics.