Interest in oxy-fuel combustion as one of the leading carbon capture technologies has grown significantly in the past two decades. Experimental studies have shown higher CO concentration in oxy-fuel diffusion flames than in traditional air-fuel flames of both gaseous and solid fuels. The higher CO concentration changes the flame profiles, and it may have impacts on pollutants formation. This pa...

We analyze the structure of diffusion flames at high pressure in the limit of large activation energy for the particular configuration of a steady flame in counterflow. We consider the fluid to be near the thermodynamic critical point in which case the effective mass diffusivity is negligible, and Soret diffusion is the dominant mechanism for fuel mass transport. Temperature and species profile...

There is considerable interest in developing fuel-flexible, low emissions turbines for power generation. One approach is based on burning a variety of lean premixed fuels with relatively low flame temperatures. Such flames can be stabilized in a low swirl burner configuration, for example, using a variety of fuels such as pure hydrogen and hydrogen-seeded hydrocarbon mixtures. However, many hyd...

Dynamics of outwardly-propagating reaction fronts inspires both fundamental and practical interests. While for the former we can mention in pass supernovae explosions and measurements of laminar flame speeds of reactive mixtures, the latter is relevant to the operation of engines and prevention of spark-initiated hazards such as accidental or intentional explosions. While a pointy-ignited, expa...

Two new 14-step and 16-step reduced mechanisms for methane-air combustion were developed with the emphasis on their capabilities to predict NO2 formation. The systematic reduction was carried out by assuming the quasi-steady state for 26~28 species in the starting mechanism with the help of a automatic mechanism reduction code. The two reduced mechanisms reproduce NO2 formation behaviors obtain...

Studies of radiation emissions from turbulent buoyant diffusion flames impinging on structural elements have applications to the development of fire models and estimation of structural integrity under large heat loads. An experimental and numerical study of radiation emissions from turbulent buoyant diffusion flames with and without impingement on a flat plate is reported. The steel plate was s...

Microgravity combustion is fundamentally characterized by the absence of buoyancy driven flows. To facilitate a large range of diagnostics on microgravity flames, it is useful to create an equivalent microbuoyant condition in an earth-based laboratory. This experiment simulates microbuoyancy using electric fields to balance local convection in a region of the flame. Previous studies used N2 coh...

Experimental propane/air Bunsen flame at atmospheric pressure are investigated in the context of DarrieusLandau (DL) instability. Results from asymptotic theory are utilized in order to estimate the non-dimensional critical length scale δc = LD/λc (LD the flame thickness and λc the critical length scale). The non-dimensional flame thickness δ = LD/L is varied either by varying the equivalence r...

In this study, 3D premixed turbulent ammonia-hydrogen flames in air were studied using DNS. Mixtures with 75%, 50% and 25% ammonia (by mole fraction the fuel mixture) equivalence ratios of 0.8, 1.0 1.2 studied. The studies conducted a decaying turbulence field an initial Karlovitz number 10. flame structure influence ratio first It was observed that increase smoothened out small scale wrinkles ...

With the increasing need of smaller power sources for satellites, energy systems and engine equipment, microcombustion pose a potential as alternative power source to conventional batteries. As the substitute fuel source for gasoline, biobutanol shows more promising characteristics than ethanol. In this study, the diffusion microflame of liquid biobutanol under electric field have been examined...