The role of the basic three-modes interaction during the free decay of magnetohydrodynamic turbulenceR. De Bartolo1 and V. Carbone1, 2
1 Dipartimento di Fisica, Università della Calabria Ponte P. Bucci, Cubo 31C, 87036 Rende (CS), Italy
2 Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM) Sezione di Cosenza, 87036 Rende (CS), Italy
received 11 October 2005; accepted in final form 21 December 2005
published online 18 January 2006
We investigate the predictability of solutions of nonlinear relaxation in two-dimensional magnetohydrodynamic equations without external forcing terms (free decay). We use a Galerkin approximation for the equations of motion by retaining only three interacting wave vectors, to reduce the system to N = 6 (when the fields have only real amplitudes) or N = 12 (when amplitudes are complex) ordinary differential equations. We found that the asymptotic state of the model with real amplitudes can be predicted, while that of the model with complex amplitudes strongly depends on the time behavior of the phases of fields.
52.30.Cv - Magnetohydrodynamics (including electron magnetohydrodynamics).
52.65.Kj - Magnetohydrodynamic and fluid equation.
52.35.Ra - Plasma turbulence.
© EDP Sciences 2006