The biggest among them was combustion instability
. Like a candle flickering from side to side as it seeks oxygen to burn, the single chamber F-1 engine multiplies that flicker into 1.5 million pounds of exploding thrust (the previous front runner at just over one-tenth of that power, the H-1 engine, came in at a mere 165,000 pounds of thrust).
It is also noticeable that the base biodiesel shows large gaps with no droplets between the wakes of airflow, which can lead to combustion instability
. It is speculated that lower viscosity, due to the water contents in fuel and positive changes in surface tension, helped the water-in-biodiesel fuel to exhibit a more evenly distributed spray formation with smaller droplets.
Fiala, Radiation from high pressure hydrogen--oxygen flames and its use in assessing rocket combustion instability
For various combustion systems and new combustion technologies, combustion instability
is always one of the main challenges and significant attention must be paid to these details in flows and combustion.
Nitu, "Diesel engine cold start combustion instability
and control strategy," SAE Paper 2001-01-1237, 2001.
With the trend toward increased fuel efficiency and low NOx emissions, today's gas turbines operate more efficiently but have to be closely monitored and controlled to avoid combustion instability
. This instability can damage components in the combustion chamber, as well as downstream components such as blades, resulting in avoidable downtime and loss of revenue.
Taken together, this information will populate a database that will prove useful for diagnosing and solving future combustion instability
refers to damaging pressure oscillations associated with oscillations in the combustion heat release rate.
This collection, translated from the 1999 Russian edition, includes accounts of significant work on facets of combustion instability
, including low frequency oscillations in liquid rocket combustion chambers, phenomenological models of the combustion process, the acoustic response of the combustion chamber, high frequency (acoustic) oscillations in a combustion chamber, nonlinear effects, application of the frequency-response method for studying the dynamical properties of the combustion zone, the stability of combustion of fuel drops in a flow of gaseous oxidizer, and bifurcations of steady combustion regimes and their effect on the onset of high-frequency oscillations.
Measures taken to eliminate a combustion instability
problem with one syngas fuel may actually exacerbate the problem with another fuel, and vice versa.