The analytical modeling of a turbulent diffusion flame behind a backward facing step

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5238147

Tsau, F H

A conventional high-Reynolds-number model using a law of the wall submodel as boundary conditions and a recently developed low Reynolds number model employing available experimental information in the near-wall region are tested, respectively. When species fluctuations are taken into account in numerical simulations, two different statistical models are postulated and incorporated in the combustion models. Hydrogen (H{sub 2}) and methane (CH{sub 4}) are the two gaseous fuels chosen for this study. The results of this research are primarily five-fold: (1) The high-Reynolds-number model predicts a shorter reattachment length than the low-Reynolds-number model does, and the high-Reynolds-number model is regarded to be inadequate in describing reacting flows. (2) The effect of combustion is to shorten the reattachment length of the flow field, and the reattachment length is more a function of the amount of heat input to the system than a function of the injection velocity or a function of the type of fuel in a reacting flow. (3) The effects of the fluctuation of the fuel mass fraction are small for the Reynolds number of the flow examined in this study. (4) Results from different statistical models are almost identical. (5) The chemical kinetics of the H{sub 2}-air system are fast enough so that the non-equilibrium effect is small in the flow under investigation.

• Research Organization: Georgia Inst. of Tech., Atlanta, GA (USA)
• OSTI ID: 5238147
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
ALKANES
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
DIFFUSION
ELEMENTS
FLAMES
FLOW MODELS
HYDROCARBONS
HYDROGEN
KINETICS
MATHEMATICAL MODELS
METHANE
NONMETALS
ORGANIC COMPOUNDS
REACTION KINETICS
REYNOLDS NUMBER
TURBULENCE