To consider the effect of pressure and temperature variation within the domain this empirical model of laminar flame speed
In the SI units, thanks to the high octane ratings and flame speed
, alcohols such as ethanol or methanol allow to improve engine thermal efficiency while reducing knock tendency [4,5], generally resulting in lower regulated emissions .
Figure 4 shows the turbulent flame speed
contour plots for the three analyses.
The start of control is passed to the turbine from "speed zero" to safe operating speed by supplying the right amount of fuel to establish the flame speed
in a way that minimizes the fatigue cycle down.
Engine speed also contributes to cycle to cycle variation in combustion, where increasing the engine speed resulted in an increase in flame speeds
and cyclic flame speed
Both inventors of the aviation gas turbine--Hans von Ohain in Germany and Frank Whittle in England--first resorted to hydrogen fuel with its more forgiving high flame speed
, before they solved liquid fuel combustion problems.
This includes extinction behaviour (how easy it is to blow out the flame), flame speed
and stability; type and quantity of emissions; fuel droplet evaporation; and reignition at low temperatures.
Furthermore, the flammability ranges do not take into account the role of turbulence (congestion) on flame speed
, which is the main element responsible for the likelihood and severity of an explosion .
damp] is damper closing time (linear drive reaction time), S is distance between a possible initial explosion place and a damper building place (flame path); v is flame speed
Compressed Ni-Ti powder cylindrical samples for are used to investigate the flame speed
and effective thermal conductivity over a range of initial sample porosities.
CHEMKIN-PRO can also perform multi-zone modeling to replicate operating conditions in various regions of the cylinder to optimize ignition, flame speed
and emission levels.
The flame speed
is a function of pressure, temperature, equivalence ratio and diluent ratio.