Abstract: A joint-scalar probability density function (PDF) model is used to simulate bluff-body stabilized turbulent non-premixed Sydney flames HM1. In Situ Adaptive Tabulation (ISAT) algorithm is used to accelerate chemistry calculations. A modified LRR-IP Reynolds stress model is applied to obtain mean flow and turbulent mixing fields. We consider three chemical kinetical schemes for methane chemistry. Simulation results are compared with experimental data. It shows that the model and mechanisms predict flow field, scalar field and local extinction well. C2 chemistry has minor effect on flame HM1.