Prandtl number

About: Prandtl number is a research topic. Over the lifetime, 15168 publications have been published within this topic receiving 337185 citations.

The Theory of Turbulent Jets

Abstract: This chapter contains sections titled: Theory of Free Turbulence, Prandtl's Old Theory of Free Turbulence, Application of Prandtl's Old Theory of Free Turbulence to Heat and Diffusion Problems, Theory of the Boundary Layer of a Two-Dimensional Turbulent Jet of Incompressible Fluid, Tollmien's Plane Turbulent Source, Tollmien's Axially Symmetric Turbulent Source, Distribution of Temperature and Constituent Concentration in the Main Region of a Jet According to Prandtl's Old Theory of Free Turbulence, Taylor's Free Turbulence Theory and Its Application, Prandtl's New Theory of Free Turbulence and Its Applications, Reichardt's Theory of Turbulent Mixing and Its Application, Determination of the Temperature Profile in a Jet on the Basis of the New Prandtl-Gortler Theory of Turbulence and Reichardt's Theory

Heat Transfer from Tubes in Crossflow

Abstract: Publisher Summary This chapter discusses the heat transfer and the hydraulic resistance of single tubes, and the banks of tubes of various arrangements in flows of gases and viscous liquids. The focus is on the important problems of the heat transfer and the hydraulic resistance of tubes, in particular with the heat transfer of single tubes, banks of tubes, and systems of tubes in crossflow. The chapter also highlights the influence of the physical properties of fluids on heat transfer. Extensive experimental data will be analyzed and will include investigations of banks of tubes of various arrangements, and a single tube in crossflow in the range of Prandtl number from 0.7 to 500 and that of Reynolds number from 1 to 2xl0 6 .

On the Spectrum of Isotropic Temperature Fluctuations in an Isotropic Turbulence

Abstract: The one‐ and three‐dimensional spectral equations for a field of isotropic temperature fluctuations in an isotropic turbulence are derived from the correlation equation. Then, except for the degenerate case of simple conductive decay, stationary fluctuation fields are postulated. Largely by dimensional reasoning and some simple postulates, forms of the temperature fluctuation power spectrum for particular wave number ranges are deduced and are compared with the results of previous analyses giving corresponding segments of the velocity spectrum. Finally, the relative ``effective cut‐off'' wave numbers of the two spectra are compared in terms of the fluid Prandtl number.

Progress in the Statistical Theory of Turbulence

Abstract: The fundamental notion of statistical mean values in fluid mechanics was first introduced by Reynolds. His most important contributions were the definition of the mean values for the so-called Reynolds' stresses and the recognition of the analogy between the transfer of momentum, heat and matter in the turbulent motion. In the decades following Reynolds' discoveries, the turbulence theory was directed toward finding semi-empirical laws for the mean motion by methods loaned from the kinetic theory of gases. Prandtl's ideas on momentum transfer and Taylor's suggestions concerning vorticity transfer belonged to the most important contributions of this period. I believe that my formulation of the problem by the application of the similarity principle has the merit to be more general and independent of the methods of the kinetic theory of gases. This theory led to the discovery of the logarithmic law of velocity distribution in shear motion for the case of homologous turbulence.