Sensitivity analysis of LES–CMC predictions of piloted jet flames

Abstract

The sensitivity of Large Eddy Simulation with Conditional Moment Closure

Numerical simulation of oxy-fuel jet flames using unstructured LES–CMC

“…The influence of this term is a subject for further research. However we note that previous work [14] has shown the influence of the e f term to be minor compared to the other terms. The final form of the CMC equation used in this work in integral form is…”

“…what conditional averages should be specified. This is further discussed in [14]. Both fully burning flamelets and inert distributions were tried for flame A1 and with either method it was seen that the flame was predicted to lift by around 0.5d.…”

“…We then go a step further by saying that the collection of LES cells mapped to a CMC cell become the CMC cell so that the faces of the CMC cell are the faces of the LES cells at the edge of the CMC cell. We follow the successful previous practice in LES-CMC [14] of modelling the conditional velocity as equal to the unconditional velocity, u|η = u.…”

“…Here we have chosen to take the value of D t based on the LES scale using the argument that the sub-LES grid motion will be responsible for the transport not included in the convection term. This is a modelling choice, but as noted earlier previous work [14] has shown the influence of the diffusion term to be minor compared to the other terms.…”

Study of a Turbulent Nitrogen-Diluted Hydrogen-Air Diffusion Flame Through Large-Eddy Simulations Coupled With a First Order Conditional Moment Closure Method

“…These terms are unclosed and therefore require modelling. The conditional velocity is assumed equal to the local unconditional filtered velocity, ̇| =, according to Garmory [2013]. The conditionally filtered scalar dissipation rate is modeled by the Amplitude Mapping Closure (AMC) model [O'Brien 1991]:…”