Prateep Chatterjee

Laminar Smoke Point Based Subgrid Soot Radiation Modeling Applied to LES of Buoyant Turbulent Diffusion Flames

Large eddy simulations (LES) of gaseous buoyant turbulent flames have been conducted with the application of a flamelet based soot-radiation model. The subgrid model applies a turbulent eddy description of soot formation, oxidation and radiation and is based on the laminar smoke point concept. Two parameters, a local turbulent strain rate and prior enthalpy loss/gain fraction influence the soot formation and radiation. Radiation heat transfer is simulated by solving the finite volume discretized form of the radiative transfer equation (RTE) with the subgrid soot-radiation model implemented. The radiant heating of surfaces in close proximity of the flames is computed and predicted heat fluxes and surface temperatures are compared against experimental data. Fire growth in a rack storage arrangement is simulated with the application of a pyrolysis model. Computed heat release rate (HRR) is compared against experimental data.

Development of a Standard Flammability Test for Water-Based Hydraulic Fluids

This paper is a review of the development of a standard flammability test method for hydraulic fluids since the 1970s. Over the past years, the test methodology for qualifying hydraulic fluids has been transformed from a qualitative assessment to a quantitative and model based assessment. The present standard test method deals with the calorimetric measurement of heat release rate of a highly atomized spray fire, fire point temperature measurement, and the determination of adiabatic flame temperature utilizing an existing NASA Combustion Equilibrium and Application Code. In this paper, we have emphasized on the detailed development of evaluating water-based hydraulic fluids.

Sustained Burning of Water-based Paint Sprays

Water-based paints used in automotive paint spray booths are prone to ignition and combustion might occur for these types of paints when finely dispersed in electrostatic spraying. An experimental study accompanied by equilibrium calculations of adiabatic stoichiometric flame temperature ( ad T ) has been conducted to investigate the burning behavior of water-based spray paints. Several spray fire tests have been carried out and the heat release rates of the flames have been measured. To compare the paints burning behavior, acetone has been added at various concentrations for the spray fire tests. The results have been compared against computed ad T values for the paint-acetone mixtures. Elemental compositions of the paints and their heats of combustion have been measured to compute ad T . A critical temperature ( cr ad T , ) at which combustion will not sustain itself is proposed to characterize the water-based paints. Completeness of combustion ( comb η ) of paint-acetone mixture spray fires has also been used to evaluate the burning behavior of the paints. Based on the critical temperature and completeness of combustion, two regimes of combustion have been identified.