Propagation of shock waves in the solar corona with 2-D loop structures

Motivated by recent observations of type II radio bursts, we study propagation of shock waves by the twodimensional numerical magnetohydrodynamic model. Explosion of a hot plasma is investigated for various ratios of the mass density and magnetic field intensity in a fan of coronal loops. Ducting of shock waves occurs along loop-like structure and ducting of possible radio emission in under-dense coronal loops is expected. This provides an alternative to classical explanation that two distinctly separated type II radio bursts are caused by two different shocks. The presented results support the idea that a single solar flare energy release with a single shock can generate coronal disturbances observed as two separate type II radio bursts.