In this study, a cam-shaped cylinder immersed in the cross-flow is investigated numerically, which is made of two circular cylinders joined by their two common tangents. The equivalent diameter of the cam-shaped cylinder D-eq is constant, which is maintained by adjusting the diameters of and the distance between the front and rear cylinders. The present study systematically investigates the effects of shape transformation of a base circular cylinder into different shapes of the cam-shaped cylinder on the flow and heat transfer characteristics. The cam-shaped cylinders with different relative diameter ratios of cylinder 1 (D-1/D-eq, = 0.2-0.84), and different relative diameter ratios of cylinder 2 (D-2/D-eq = 0.5-0.9) for the two Reynolds numbers (Re = 100, and 200) are considered. The functional dependence of drag coefficient (C-D) and lift coefficient (C-Lmax) on D-1/D-eq, and D-2/D-eq are examined. C-D decreases with an increase in Re and a decrease in D-2/D-eq, respectively, while the Strouhal number (St) increases with a decrease in D-2/D-eq. The average Nusselt number ((Nu) over bar) increases with an increase in Re and decreases with a decrease in D-2/D-eq. The change in (Nu) over bar is almost negligible for a low D-1/D-eq. Different regimes are proposed for the design parameters selection for high (Nu) over bar and low C-D. In the regime of constrained design and flow conditions, the present cam-shaped cylinders show their superiority over the other bluff bodies in terms of enhanced heat transfer and reduced drag. (C) 2018 Elsevier Ltd. All rights reserved.