One of the well-known properties of turbulent, premixed flames is that their speed of propagtion is correlated to the intensity of the turbulence they encounter. A simple consequence is that these types of flames are inherently unstable. Given a source of turbulence, if the flame is propagating faster than the mean flow, it will drift upstream and encounter increased turbulent intensities that ...

Thermal radiation properties of turbulent premixed flames have received little attention in the past perhaps because of the lower radiative heat loss compared with that for non-premixed flames. However, the high-temperature sensitivity of NO kinetics and the importance of radiation in near-limit laminar premixed flames provide fundamental reasons for studies of radiation properties of turbulent...

Nonlinear model equation for weakly turbulent premixed flames with realistic fuel expansion is proposed. The equation describes both the hydrodynamic flame instability and flame response to external turbulence in the regime of flamelets. On the basis of the proposed equation the velocity of turbulent flames is investigated for the cases of both weak and relatively strong turbulence. Comparison ...

the present study is concerned with measuring and simulating soot formation and combustion in turbulent liquid fuel spray flames. soot concentrations inside the combustor are measured by filter paper technique. the simulation is based on the solution of the fully-coupled conservation equations for turbulent flow, chemical species kinetic modeling, fuel droplet evaporation and combustion and soo...

Radiative heat transfer has a significant effect on nitric oxide (NO) formation in turbulent non-premixed flames. Consequently, predictive models of turbulent non-premixed flames must include an accurate radiation submodel. To investigate the importance of radiation submodels in modeling NO formation, multiscalar measurements of temperature and species were coupled with radiation measurements i...

A simple, semi-analytic representation is developed for nuclear burning in Type Ia supernovae in the special case where turbulent eddies completely disrupt the flame. The speed and width of the “distributed” flame front are derived. For the conditions considered, the burning front can be considered as a turbulent flame brush composed of corrugated sheets of well-mixed flames. These flames are a...

It is well known that buoyancy has a major influence on the flow structure of turbulent nonpremixed jet flames. For example, previous studies have shown that transitional and turbulent jet flames exhibit flame lengths that are as much as a factor of two longer in microgravity than in normal gravity. The objective of this study is to extend these previous studies by investigating both mean and f...

The series of workshops on Measurement and Computation of Turbulent Nonpremixed Flames (TNF) facilitates collaboration and information exchange among experimental and computational researchers in the field of turbulent combustion. The emphasis is on fundamental issues of turbulence-chemistry interaction in flames that are relatively simple in terms of both geometry and chemistry. The TNF Worksh...

Turbulent lean premixed dodecane/air flames are simulated in a doubly-periodic domain using detailed kinetics and transport over a range of Karlovitz number. We observe extensive thickening of thermal profiles through the flames that increases with turbulent intensity. The high Lewis number of the flames acts to suppress wrinkling of the flame resulting in considerably lower turbulent flame spe...

A compressible single step chemistry Direct Numerical Simulation (DNS) database of freely propagating premixed flames has been used to analyze different entropy generation mechanisms. The entropy generation due to viscous dissipation within the flames remains negligible in comparison to the other mechanisms of entropy generation. It has been found that the entropy generation increases significa...