In current engineering fluid flow systems, space is restricted and turning a fluid while trying to minimize pressure loss and maintain flow uniformity can be a challenge. Attempts to solve this problem have mainly been through the use of a trail and error methodology both experimentally and numerically, which invokes some experiential knowledge or intuition. With recent developments in design optimization research, certain methods can now be used to remove the qualitative and imprecise nature of intuition and experience. Since this problem involves finding the shape of the vanes as well as their number and distribution, it seems appropriate to investigate it using a topology optimization technique. Topology optimization presents a general design optimization approach that can produce non-conventional designs. This technique has been used in the structural dynamics field for the design of bridges and aerodynamic structures, among others. Recently, the fluid dynamics community has adopted topology optimization for low to moderate Reynolds number flows. These applications mainly consider the design of channel walls and not the design of the internal structures with fixed boundaries, like turning vanes for a fluid flow system. Design of turning vanes is an important issue for engineering applications due to size and space constraints. Developing tools to optimize these designs can reduce costs and produce more efficient fluid flow systems for heating and cooling or fuel injection. In this study, a topology optimization technique using a low-fidelity potential flow model as a surrogate for a high-fidelity viscous flow model is proposed with the goal of finding the optimal design and layout of turning vanes in moderate to high Reynolds number flow.