A numerical study of surface roughness effects on the flow behavior of Nanofluid in the microchannel

Abstract:
This paper numerically investigates the effect of surface roughness on the flow behavior of AL2O3-H2O nanofluid in rectangular microchannels with the finite element method. Two-dimensional simulations were carried out at different rough rectangular microchannels, the rough surface of which was is defined by fractal geometry method based on W-M wave function with fractal dimension D and root mean square roughness σ. During the research process, the corresponding changes of flow characteristics are analyzed by adjusting the parameters and associated with the relative roughness length ratio epsilonl to facilitate comparative analysis. Results show that epsilonl has a great effect on both y-direction velocity and pressure drop change rate, and the velocity component in the y-direction has a larger fluctuation amplitude near the wall while epsilonl is increased greatly, and the pressure drop change rate increases as epsilonl increases. The influence order of parameters on Po is obtained through epsilonl with H, σ, D, and L in turn.