Unsteady oblique stagnation point flow with improved pressure field and fractional Cattaneo–Christov model by finite difference-spectral method

Unsteady oblique stagnation point flow, heat and mass transfer of generalized Oldroyd-B fluid over an oscillating plate are investigated. The upper-converted derivative is introduced to the constitutive equation of fractional Oldroyd-B fluid. The terms of pressure are inventively solved by means of the momentum equation far from the plate. Furthermore, fractional Cattaneo–Christov double diffusion model is employed firstly. It is worth mentioning that the numerical solution of oblique stagnation point flow is obtained by finite difference-spectral method for the first time. The convergence is verified by constructing numerical example. Finally, the influence of related parameters on the velocity, temperature and concentration are performed graphically in detail. It is interesting that the velocity, temperature and concentration intersect respectively with different order of the fractional derivative, which reflects the memory characteristic of fluid. The larger Nusselt number and Sherwood number are, the stronger convective heat and mass transfer will be, so that the temperature and concentration are increased respectively.