Spiral defect chaos in a model of Rayleigh-Benard convection

A numerical solution of a generalized Swift-Hohenberg equation in two dimensions reveals the existence of a spatio-temporal chaotic state comprised of a large number of rotating spirals. This state is observed for a reduced Rayleigh number $\epsilon=0.25$. The power spectrum of the state is isotropic, and the spatial correlation function decays exponentially, with an estimated decay length $\xi \approx 2.5 \lambda_{c}$, where $\lambda_{c}$ is the critical wavelength near the onset of convection. Our study suggests that this spiral defect state occurs for low Prandtl numbers and large aspect ratios.