Numerical simulation of mantle convection using a temperature dependent nonlinear viscoelastic model

Abstract. In the present article, the mantle convection is simulated numerically using a temperature dependent non-linear viscoelastic model for the first time. The numerical domain of problem is con sidered as a 4000 km*2000 km rectangular box and the CFD simulation is performed using finite volume method. Unlike the previous works which had been investigated the mantle convection using the linear viscoelastic models or simple nonlinear inelastic viscous equations (such as power law or cross equations), it is solved via the nonlinear Giesekus constitutive equation. Because of large-scale creeping flow in geometry and time, it is shown that the results of Giesekus equation are more reliable for this problem. The main innovative aspects of current study is investigation of temperature dependency of rheological properties of mantle including viscosity, normal stress differences and relaxation time using appropriate equations of state. The variation of gravitational acceleration with depth of Earth and the effect of the work of stress field (viscous dissipation) on mantle convection are also simulated for the first time.