The Rayleigh number is given as the product of this quantity and the Grashof factor, while the Peclet number is the product of this term and the Reynolds number.  
This dimensionless quantity is raised to the two-thirds power in one equation for the Chilton-Colburn j-factor, and in a case where this quantity is high, one relation concerning relative boundary layer thicknesses are given by the relation 0.975 times this quantity raised to the one-third power.  The mass transfer variety of this dimensionless quantity is known as the Schmidt number, and replaces a factor in its formulation with the mass transfer coefficient D.  The Rayleigh number is given as the product of this quantity and the Grashof factor, while the Peclet number is the product of this term and the Reynolds number.  For 10 points, name this dimensionless quantity defined as the ratio of the kinematic viscosity of a fluid to its thermal diffusivity.
This dimensionless quantity is raised to the two-thirds power in one equation for the Chilton-Colburn j-factor, and in a case where this quantity is high, one relation concerning relative boundary layer thicknesses are given by the relation 0.975 times this quantity raised to the one-third power.  
Prandtl number