This paper presents the study of the effects of anisotropy on fully developed forced convection heat transfer in a horizontal cylinder with a constant heat flux applied on its outer wall side. By applying mathematical model, using continuity, momentum and energy equations, the effects of essential parameters, such as A*, Darcy number Da, modified Brinkman number Br*, as well as the presence or absence of heat generation and fractional heating on the heat transfer and fluid flow characteristics, in the horizontal cylinder were determined and depicted in graphs. Consequently, it was found that for a particular value of A* (called A*c), the sign of Nusselt number changed. Also, for special values of A* (called *VA), the relative Nusselt number deviations δ which show the relative deviations between Nusselt number with and without frictional heating term, do not change with Da numbers.
