| 释义 |
Prandtl|prænt(ə)l|
[Name of Ludwig Prandtl (1875–1953), German physicist.]
Prandtl number: a dimensionless parameter used in calculations of heat transfer between a moving fluid and a solid body, equal to cpv/k, where cp is the heat capacity of unit volume of the fluid, v is its kinematic viscosity, and k its thermal conductivity.
1933W. H. McAdams Heat Transmission iv. 96 Prandtl number = 1/Stanton group. 1954R. Stephenson Introd. Nucl. Engin. vi. 245 The ratio of the quantity of heat transferred by convection to the quantity of heat transferred by conduction is given by the value of the Prandtl number for the fluid. 1958[see Nusselt]. 1974F. M. White Viscous Fluid Flow ii. 84 Table 2-1 gives values of the Prandtl number for various fluids at 68°F. It shows that liquid metals have [a] very small Prandtl number, gases slightly less than unity, thin liquids somewhat higher than unity, and oils a very large value of Pr. |