What is considered high compression ratio?
Anything over 10:1 is a high compression ratio. Anything over 12:1 is “highly compressed”. 87 Octane is both a high and low compression fuel. There are no different levels of high compression beyond calculated ratio and personal opinion.
Does fuel consumption decrease with altitude?
Yes, fuel consumption decreases with altitude. A: Yes, the fuel burn affects the weight of the airplane. As fuel is consumed, the weight decreases. This results in less lift being required to maintain altitude, consequently less fuel is needed to produce the necessary thrust.
How does altitude affect the compression ratio of an engine?
Altitude doesn’t affect the compression ratio. If 50 cm3 is compressed down to 5 cm3 then the compression ratio is 10:1 regardless of how much air is actually in the initial 50 cm3. Thanks guys. Perhaps I was a little inspecific.
Why does jet engine fuel consumption decrease with weight?
Hight altitude – Less air density – Lesser resistance – Less fuel required to spin the compressor faster. There is an optimum altitude in reference to speed and thrust which increases as weight reduces.
Why does fuel consumption decrease with increasing aircraft altitude?
At the left, we see that the thrust decreases with altitude. At the right, we observe that the TSFC actually decreases with altitude as well. However, I think this is counter-intuitive. I understand that decreases with altitude, since density (and therefore mass flow rate) decreases when the airplane goes up.
How is the fuel-air ratio of a ramjet determined?
The fuel-air ratio, , depends on the fuel properties (), the desired flight parameters (), the ramjet performance (), and the temperature of the atmosphere (). Figure 11.13:Control volume over the burner 11.6.3.3Specific impulse, The specific impulse for the ramjet is given by