dominates when U> 1. The contribution of both heat transfer
and fluid friction to entropy generation are equal when
U= 1. The Bejan number Be takes the values between 0
and 1 (see [43]). The value of Be =1 is the limit at which
the heat transfer irreversibility dominates, Be =0 is the
opposite limit at which the irreversibility is dominated by
the combined effects of fluid friction and magnetic field and
Be = 0.5 is the case in which the heat transfer and fluid