Time-step changes and parity effects in TLM thermal models

Many time domain numerical techniques for thermal and mass diffusion can display anomalies such as 'jumps-to-zero'. Investigations into transmission line matrix (TLM) networks have helped to identify the underlying causes for these and have shown how the accuracy of a TLM model can be significantly improved by the correct choice of observation point as well as placement of stubs and location of boundaries. A study of the process of TLM mesh decimation is likely to lead to a better understanding of the nature of diffusion TLM, whereby a lossy wave equation is used to model a parabolic equation.