  In this paper, we applied the Shan-Chen multiphase Lattice Boltzmann method
to simulate two different parameters, contact angle (a static parameter) and
slip length (a dynamic parameter), and we proposed a relationship between them
by fitting those numerical simulation results. By changing the values of the
strength of interaction between fluid particles (SIF) and the strength of
interaction between fluid and solid surface (SIFS), we simulated a series of
contact angles and slip lengths. Our numerical simulation results show that
both SIF and SIFS have little effects on the relationship between contact angle
and slip length. Using the proposed relationship between slip length and
contact angle, we further derived an equation to determine the upper limit of
nano-particles' diameter under which drag-reduction can be achieved when using
nano-particles adsorbing method.
