What is Sherwood number formula?
where Sh is the Sherwood number, defined as Sh = kL dB/ D, where D is the diffusivity of the dissolved gas in the liquid and which can be estimated.
What does the Sherwood number tell us?
Sherwood number represents the ratio between mass transfer by convection (β) and mass transfer by diffusion (δ/L). It is the mass transfer equivalent of Nusselt Number, Nu, and is a function of Reynolds Number, Re, and Schmidt Number, Sc.
What are the physical significance of Schmidt number and Sherwood number?
The Schmidt number is the ratio of the shear component for diffusivity viscosity/density to the diffusivity for mass transfer D. It physically relates the relative thickness of the hydrodynamic layer and mass-transfer boundary layer. The heat transfer analog of the Schmidt number is the Prandtl number (Pr).
What is the significance of Graetz number?
This number is useful in determining the thermally developing flow entrance length in ducts. A Graetz number of approximately 1000 or less is the point at which flow would be considered thermally fully developed.
What is meant by mass transfer coefficient?
In engineering, the mass transfer coefficient is a diffusion rate constant that relates the mass transfer rate, mass transfer area, and concentration change as driving force: Where: is the mass transfer coefficient [mol/(s·m2)/(mol/m3)], or m/s.
What is Lewis number in mass transfer?
The Lewis number (Le) is a dimensionless number defined as the ratio of thermal diffusivity to mass diffusivity. It is used to characterize fluid flows where there is simultaneous heat and mass transfer.
What is the dimension of the Schmidt number?
What is the dimension of the Schmidt number? Explanation: Schmidt number = v/D and it has no dimensions. 4.
What is GZ in fluid mechanics?
In fluid dynamics, the Graetz number (Gz) is a dimensionless number that characterizes laminar flow in a conduit. The number is defined as: Gz = D H L Re Pr. Pr is the Prandtl number.
How is Graetz number calculated?
The Graetz number equals the product of the specific heat capacity, diameter, characteristic length, characteristic speed and the mass density divided by the thermal conductivity and length.
What is the Sherwood number analogous to?
Since Re and Sc are both dimensionless numbers, the Sherwood number is also dimensionless. These correlations are the mass transfer analogies to heat transfer correlations of the Nusselt number in terms of the Reynolds number and Prandtl number.
What is kC in mass transfer?
The convective mass transfer coefficient kC is a function of geometry of the system and the velocity and properties of the fluid similar to the heat transfer coefficient, h. 2.3 Significant Parameters in Convective Mass Transfer. Dimensionless parameters are often used to correlate convective transfer data.