# Internal forced convection

Internal heat and mass transfer have significant applications in a variety of technologies, including heat exchangers and electronic cooling. Internal convective heat and mass transfer can be classified as either forced or natural convection. An initial simple approach to internal convective heat transfer is to utilize the dimensional analysis to obtain important parameters and dimensionless numbers for the steady laminar flow of an incompressible fluid in a convectional tube [1], i.e.,

 h = f(k,μ,cp,ρ,u,D,x,ΔT) (1)

The local heat transfer coefficient is a function of the fluid properties (viscosity, μ; thermal conductivity, k; density, ρ; specific heat, cp), geometry (D), temperature (ΔT), and flow velocity (u). In dimensionless form,

 $\text{Nu}=g(\operatorname{Re},\Pr ,x/D)$ (2)

The above relation indicates that the local Nusselt number for flow in a circular tube is a function of the Reynolds number, Prandtl number, and x/D. The goal of this chapter is to develop the heat and mass transfer coefficients for various internal flow configurations under different operating conditions.

## References

1. Faghri, A., Zhang, Y., and Howell, J. R., 2010, Advanced Heat and Mass Transfer, Global Digital Press, Columbia, MO.