Modeling and characterization of surface roughness effect on fluid flow in a polydimethylsiloxane microchannel using a fractal based lattice Boltzmann method

In micro and nano flows, the fluid flow pattern is sensitive to many intrinsic parameters such as surface roughness. In this letter, we have presented the capture of variations in fluid flow in polydimethylsiloxane(PDMS) microfluidic channels with respect to surface roughness. The velocity of the fluid is measured experimentally and also simulated using a mesoscopic lattice Boltzmann method (LBM). For simulations, the surface roughness is implemented using a fractal based approach. The Weierstrass-Mandelbrot(WM) mathematical function is explored for realizing various rough surfaces by tuning the fractal dimension parameter. The results show that the computational fluid dynamics model, which incorporated surface roughness, has a better agreement with the experimental results than the model without roughness.