Two approaches to incorporate the effects of rotation and curvature in scalar eddy viscosity models are explored. One is the “Modified coefficients approach” – to parameterize the model coefficients such that the growth rate of turbulent kinetic energy is suppressed or enhanced. The other is the “Bifurcation approach” – to parameterize the eddy viscosity coefficient such that the equilibrium solution bifurcates from healthy to decaying solution branches. Simple, yet, predictive models in each of these two approaches are proposed and validated on some benchmark test cases characterized by profound effects of system rotation and/or streamline curvature. The results obtained with both the models are encouraging.