Abhishek T Mendhe
M.Tech (Heat Power)
Ramdeobaba College of Engineering & Management ,Nagpur
What do you mean by flame?
A flame is a self-sustaining propagation of a localized
combustion zone at a subsonic velocities.
Classification of Flames:-
A)laminar premixed flame B)Turbulent premixed flame
example: Bunsen burner, LPG domestic burner, SI Engine
2.Non Premixed flames or diffusion flames
example: candle flame
LAMINAR PREMIXED FLAMES
A Bunsen burner is a very good example of laminar
A jet of fuel at the base induces a flow
of air through the variable area port.
Air and fuel are mix as they flow up
through the tube.
Typically Bunsen burner consist
of duel flame,
1) Inner premixed flame
2) Outer diffusion flame
LAMINAR FLAME SPEED
It is defined as the apparent average velocity that the
unburned mixture will acquire ,if it were to pass through the conical
flame surface .
It is important for flame to remains
Stationary and flame shape.
From diag. laminar flame speed
Negligibly small heat release
Certain chemical reactions take place in this zone.
most of the chemical energy is released in the form
Decomposition of fuel takes place, leading to intermediate
Reaction zone is very thin as compared to the preheat
Temperature gradient and concentration gradient are high.
CO2 and H2O are formed;
No heat release in this zone
1.Analytic Combustion by Professor Anil W. Date.
2.NPTEL lectures by Professor D.P. Mishra.
3.An Introduction to Combustion by Stephen R. Turns.