Pressure Drop Characteristics in Continuum-Based Laminar Compressible Microconvective Flow

Pressure drop (Δp) in microconvective flows is of basic importance in several applications in which fluid flows through micropassages for heat removal. This investigation studies the effects of variations in air properties due to convective heat transfer on basic laminar microflow parameters: wall shear stress, Fanning friction factor, pressure drop, and Darcy friction factor. These effects are classified as direct and indirect. The direct effects are due to the variations in fluid flow parameters, gas density (ρ) and dynamic viscosity (μ), which determine the axial velocity field, wall shear stress, and pressure drop. The indirect effects are due to the variations in fluid thermal parameters, specific heat at constant pressure, and thermal conductivity, which affect the temperature field; consequently, ρ and μ are affected. Numerical results show that microflow characteristics are significantly influenced by variable fluid properties, and predicted Δp drastically differed at low Reynolds number and high heat flux.

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