An a priori analysis of subfilter-scale (SFS) species structure important to estimate chemical reaction rates in large-eddy simulation (LES) is performed using direct numerical (DNS) turbulent premixed flame at turbulence Reynolds number Re0=329 and Karlovitz Ka0=7.23 with semi-detailed finite-rate chemistry. Differences between the complete extracted from DNS those estimated LES-filtered varia...

We consider the propagation of laminar premixed flames in the presence of a parallel flow whose scale is smaller than the laminar flame thickness. The study addresses fundamental aspects with relevance to flame propagation in narrow channels, to the emerging micro-combustion technology, and to the understanding of the effect of small scales in a (turbulent) flow on the flame structure. In part,...

A method of video flame detection based on multi-feature fusion is presented in this paper. Physical characteristics of flame, including color clues, flame movement and flame flicker are incorporated into the scheme to detect fires in color video frames. Firstly, mean filtering was used to smooth the video frames and a flame color filtering algorithm was adopted to extract flame candidate regio...

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...

Tribrachial or triple flames represent a class of partially premixed flames that generally contain three spatially distinct but synergistically coupled reaction zones, namely a rich premixed, a lean premixed, and a nonpremixed reaction zone. The generally considered flow arrangement for burner-stabilized triple flames involves a rich mixture issuing from a central port and a lean mixture from t...

The title compound, C(18)H(14)Cl(10), is a decachlorinated commercial flame retardant. The structure determination confirms the relative stereochemistry. The central eight-membered ring is in a chair-type conformation. In the crystal structure, there are no significant inter-molecular inter-actions and mol-ecules are separated by normal van der Waals distances.

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...

We consider a three-dimensional thermal-diffusion model for a premixed burner flame. Many experimental and theoretical works in condensed-phase and gas combustion show that the flame front may propagate in a number of different ways. The structure and stability properties of the front depend essentially on the physical parameters of the model. This article describes the use of the symbolic mani...

Original scientific paper In the numerical simulation research of gas turbine combustor, there are plenty repetitive operations such as modelling and meshing. Parametric design idea is about simplifying it. This paper establishes a parametric modelling system of gas turbine combustor, mainly for the flame tube components, which includes parametric modelling and simple mesh generation. Taking a ...

Complicated environmental problems inevitably arise when technology advances. One major environmental problem is the presence of electromagnetic radiation. Long-term exposure to electromagnetic radiation can damage people’s health in many ways. Therefore, this study proposes producing composite boards with electromagnetic shielding effectiveness and thermal insulation by utilizing the structure...