Heat Transfer in Turbulent Flow. Part 2. Velocity and Temperature Distributions

Аннотация

Relations describing the velocity and temperature distributions are studied on the basis of an analysis of a large amount of experimental data from investigations of temperature fields in turbulent flow of different media – air, water (P ≥ 1) and liquid metal (Pr << 1). It is noted that the use of the coefficients ν_t and a_t of turbulent transfer of momentum and heat, respectively, as well as their ratio – the Prandtl number – for the calculation of the heat transfer intensity can lead to significant errors, though in so doing an apparent correspondence is observed between the experimental and computations data expressed in logarithmic coordinates in the form Nu = ƒ(Re) or Nu = ƒ(Pr), Nu = ƒ(Pe). It is concluded that in engineering calculations of heat transfer in turbulent flow it is preferable to use relations based on the velocity and temperature distributions at Pr = const.