Abstract: A numerical investigation is carried out to study the effect of splitter’s inclination angle behind an inclined square cylinder on the forced convection heat transfer in a plan channel using the lattice Boltzmann method (LBM). The simulations are conducted for the pertinent parameters in the following ranges: the Reynolds number Re=50–300, the gap ratio G/d = 2, and the splitter’s inclination angle θ = 0 ^?–90^?. The results show
that with the increase in the angle of the splitter, the drag coefficient initially decreases and then increases. Moreover, the time-averaged Nusselt number at a certain angle increases noticeably.

Key words: variable thickness, natural frequency, non-linearity, perturbation variation method