1. The problem asks about the stability of travelling wave solutions of the radially symmetric Stefan problem in 3 dimensions. 2. The Stefan problem models phase changes, such as melting or freezing, with a moving boundary whose position depends on heat diffusion. 3. Travelling wave solutions describe interfaces moving at constant speed without changing shape. 4. Stability analysis involves perturbing the travelling wave solution and studying whether perturbations grow or decay over time. 5. For the radially symmetric Stefan problem in 3D, the governing equations include heat equations in each phase and boundary conditions at the moving interface. 6. Linearizing around the travelling wave solution leads to an eigenvalue problem determining stability. 7. Typically, stability depends on parameters like surface tension, latent heat, and initial conditions. 8. Results in literature show that under certain conditions, travelling wave solutions are stable, meaning perturbations decay and the wave shape persists. 9. Conversely, instability can lead to interface deformation or pattern formation. 10. In summary, the stability of travelling wave solutions in the 3D radially symmetric Stefan problem depends on physical parameters and can be analyzed via linear stability analysis of the governing PDEs and boundary conditions.