LAUSR

The stability characteristics of the viscous fluid–viscoelastic fluid interface are investigated in a region confined by two rigid cylindrical surfaces. Walter’s B viscoelastic fluid is taken for the analysis and the fluid phases are transferring heat along with mass from one phase to the other. The gravitational acceleration effect is neglected and therefore, the interface is unstable due to surface tension. Using the linear stability analysis, the implicit expression for the critical wave number is derived analytically in terms of associated physical parameters and solved through the Newton–Raphson method. The various plots are made in terms of perturbations growth rate and critical wave number showing the behavior of flow variables. It is found that the instability of the interface decreases if the transfer of heat is increased. Walter’s B viscoelastic fluid interface is more unstable than the equivalent Newtonian fluid interface. The density of Walter’s B fluid resists the perturbation’s growth while viscoelasticity has an inverse effect.