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This paper here gives a good overview of water injection. It suggests for injecting water into the compressor, a 300 gallon tank is necessary, for a 2.2% water to core air flow ratio (the historical …

There are two factors that determine the bypass ratio (or rather, how it may change): The first is the relative diameter of the fan, compared to the core. Obviously, this is fixed in the design proc …

Water is kept out because the oil is supplied to the bearings at a higher pressure than the surrounding air, so the oil mist is blowing away the air, not the other way around.

There are two advantages; It's easier to match the compressor rotational speed with the turbine. Typically, the first stages of the compressor want to rotate slower than the turbine is required to r …

The statement about the rotor blades ("the rotors increase the speed of the air and descrease the pressure") is not correct, because Bernoulli's Equation does not apply in this situation. Hence, the s …

See this answer for the difference between a SAC and DAC combustor. The EASA type certificate for the CFM56-7 also identifies which engines have the DAC and which have the SAC. The answer depends on e …

Very simply, a turbine has fewer stages than the compressor, because the flow in the turbine is going in the direction of reducing pressure - the air wants to go that way naturally. But a compressor h …

Yes, when the AB is lit, the nozzle needs to be opened, because the increase in exhaust temperature causes a decrease in density (pressure remains about the same), and so the same mass flow needs a bi …

For the combustor, I say the answer is no, because what is limiting the fuel rate, isn't the amount of oxygen (gas turbine combustors run very lean), but the ability of the turbine materials to withst …

A geared turbofan can spin a different fan at a different speed than an otherwise equivalent non geared engine. But a geared turbofan does not have the ability to spin additional fans at the same rpm, …

TOGA thrust is not always 100% N1 (or N2), because TOGA thrust is actually not about delivering the absolute maximum thrust that can be provided. Rather, it's about delivering a guaranteed large amoun …

"N1" is the low pressure shaft speed, and "N2" is the high pressure shaft speed. N1 and N2 throttle cycles are when the throttle is moved up-down-up (or vice-a-verse), which causes the N1 and N2 speed …

The power to drive a fan through a gearbox is not beyond current technical capability. Pratt & Whitney have developed the geared turbofan, the PW1000G that first ran in 2008 and entered commercial use …

There are two primary modes of turbine blade failure, that can be predicted, and hence are used to determine the lives of turbine blades at which they need to be replaced. One is called "creep". The …

The CF34-3and CF34-10E are quite different engines. The -10 produces more thrust for a number of reasons: It has a higher mass flow. The CF34-3 has a 44 inch fan, while the -10E has a 54 inch fan. So …