Abstract Direct and large eddy simulations (DNS and LES) of ...


22 Φεβ 2014 (πριν από 3 χρόνια και 5 μήνες)

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Direct and large eddy simulations (DNS and LES) of turbulent combustion including
pollutant formation and radiative heat transfers are conducted coupling three specific
parallel fortran codes though the specialized language CORBA. CORBA allows to
couple codes written in different programming languages and running on distant
computers. Data’s exchanges are made via Internet protocols.

The CERFACS’s code called AVBP is used to compute turbulent combustion and a self-
modified AVBP version to compute NOx production. Radiative heat transfer is computed
by using a self-adapted version of EM2C Laboratory’s codes (ray-tracing method as
radiative transfer method and CK model as gas radiative properties model). The
combustion code solves Navier-Stokes, main species and energy balance equations.
From these data, the second code estimates NOx formation whereas third one
determines radiative heat transfer of gases CO2 and H2O.

The different kinds of calculations are very hard to be simulated together because of the
time scale of each phenomenon. Radiative heat transfer is based on a convective time
of large structures, pollutant formation on a chemical time and acoustic phenomenon
induced by combustion on an acoustic time. Our approach takes advantage of the
different characteristic time scales involved to reduce the overall computational times.
Successful validation cases show the effect of the radiative heat transfer on temperature
fields and then on pollutant species fields. Pollutants species levels are very sensitive to
temperature and then decrease.