Hydro-thermo-fluidic aspects of Oldroyd B fluid with hybrid nanostructure subject to low and moderate Prandtl numbers

PurposeThe major goal of this article is to investigate flow and thermal aspects of Oldroyd B with hybrid nanostructure subject to a radially stretched surface under the influence of low and moderate Prandtl numbers.Design/methodology/approachThe non-dimensional governing equations are solved considering BVP4C in MATLAB as instrumental.FindingsEntropy generation effect is analyzed. Radial velocity and entropy generation exhibit opposite effect in response to amplified relaxation and retardation time parameters in case of both low and moderate Prandtl numbers. Augmented relaxation and retardation time parameters controls heat transfer rate.The results show that increasing the aspect ratio increases both the average Nusselt and entropy generation numbers for each value of the Prandtl number, while increasing the prandtl number decreases both. There is also a minimum value for the entropy generation number at a given relaxation and retardation parameter.Research limitations/implicationsAssume that the Oldroyd B fluid is dispersed with hybrid nanostructure in order to ameliorate thermal conductivity of Oldroyd B fluid so as to make it as best coolant.Practical implicationsThe low range of Prandtl number comprising particles of air, gas, etc. and moderate range of Prandtl number comprising particles of honey, thin motor oil, or any non-Newtonian liquid. The hybrid nanofluid is radiative in nature. Also, the effects of significant physical parameters on entropy generation are highlighted. The entropy generation number intensifies due to the rise in temperature difference parameter at low/moderate Prandtl number effectively. Entropy minimization can lead to the amelioration of available energy thereby enhances the efficiency of several thermal systems.Originality/valueThis article's primary goal is to investigate the flow and thermal aspects of Oldroyd B with a hybrid nanostructure subject to a radially stretched surface under the influence of low and moderate Prandtl numbers.