Model Calculation of Concurrent Flame Spread Over a Thin Solid in a Flow Tunnel
Title | Model Calculation of Concurrent Flame Spread Over a Thin Solid in a Flow Tunnel PDF eBook |
Author | Hsin-Yi Shih |
Publisher | |
Pages | 194 |
Release | 1997 |
Genre | |
ISBN |
A Model of Concurrent Flow Flame Spread Over a Thin Solid Fuel
Title | A Model of Concurrent Flow Flame Spread Over a Thin Solid Fuel PDF eBook |
Author | National Aeronautics and Space Administration (NASA) |
Publisher | Createspace Independent Publishing Platform |
Pages | 158 |
Release | 2018-07-17 |
Genre | |
ISBN | 9781722903831 |
A numerical model is developed to examine laminar flame spread and extinction over a thin solid fuel in lowspeed concurrent flows. The model provides a more precise fluid-mechanical description of the flame by incorporating an elliptic treatment of the upstream flame stabilization zone near the fuel burnout point. Parabolic equations are used to treat the downstream flame, which has a higher flow Reynolds number. The parabolic and elliptic regions are coupled smoothly by an appropriate matching of boundary conditions. The solid phase consists of an energy equation with surface radiative loss and a surface pyrolysis relation. Steady spread with constant flame and pyrolysis lengths is found possible for thin fuels and this facilitates the adoption of a moving coordinate system attached to the flame with the flame spread rate being an eigen value. Calculations are performed in purely forced flow in a range of velocities which are lower than those induced in a normal gravity buoyant environment. Both quenching and blowoff extinction are observed. The results show that as flow velocity or oxygen percentage is reduced, the flame spread rate, the pyrolysis length, and the flame length all decrease, as expected. The flame standoff distance from the solid and the reaction zone thickness, however, first increase with decreasing flow velocity, but eventually decrease very near the quenching extinction limit. The short, diffuse flames observed at low flow velocities and oxygen levels are consistent with available experimental data. The maximum flame temperature decreases slowly at first as flow velocity is reduced, then falls more steeply close to the quenching extinction limit. Low velocity quenching occurs as a result of heat loss. At low velocities, surface radiative loss becomes a significant fraction of the total combustion heat release. In addition, the shorter flame length causes an increase in the fraction of conduction downstream compared to conduction to the fuel. The...
A Model of Concurrent Flow Flame Spread Over a Thin Solid Fuel
Title | A Model of Concurrent Flow Flame Spread Over a Thin Solid Fuel PDF eBook |
Author | Paul Vincent Ferkul |
Publisher | |
Pages | 160 |
Release | 1993 |
Genre | |
ISBN |
A Model of Flame Spread Over a Thin Solid in Concurrent Flow with Flame Radiation
Title | A Model of Flame Spread Over a Thin Solid in Concurrent Flow with Flame Radiation PDF eBook |
Author | Ching-Biau Jiang |
Publisher | |
Pages | 312 |
Release | 1995 |
Genre | Flame spread |
ISBN |
A Three-dimensional Model of Flame Spread Over a Thin Solid in Low-speed Concurrent Flow
Title | A Three-dimensional Model of Flame Spread Over a Thin Solid in Low-speed Concurrent Flow PDF eBook |
Author | Hsin-Yi Shih |
Publisher | |
Pages | 318 |
Release | 2000 |
Genre | |
ISBN |
Fourth International Microgravity Combustion Workshop
Title | Fourth International Microgravity Combustion Workshop PDF eBook |
Author | |
Publisher | |
Pages | 546 |
Release | 1997 |
Genre | Combustion |
ISBN |
Concurrent Flow Flame Spread Study
Title | Concurrent Flow Flame Spread Study PDF eBook |
Author | Hai-Tien Loh |
Publisher | |
Pages | 318 |
Release | 1986 |
Genre | |
ISBN |