8

This depended strongly on the flight altitude. Staying at low level for the full mission meant that the Me-262 would run out of fuel within 40 to 50 minutes. Climbing above 6 km (20,000 ft) would extend that time to 90 minutes. Time to climb to 9 km was 13.2 minutes, so that would leave a time for engaging the enemy of 60 minutes. Considering that typical ...


6

The airplanes in the photo are quite far apart, at least 1-2 lengths between each (it's just the long lens making them look cheek by jowl), and while in line going straight, they are only using a little over idle thrust to get rolling when required, so the jet blast effects are negligible. The main factor is FOD (foreign object damage) kicked up, and at ...


4

The ambient air will only move through the engine from back to front when the aircraft is on the ground. Even then, the engine would have to be off for that to happen. Otherwise, the thrust from the engine would be too great. Even the electric or air starter should have enough torque to overcome the ambient air pressure before fuel ignition is achieved. Go ...


4

Only when on the ground, and at the inlet end, where a strong wind from the side and behind could influence the engine's ability to draw air in the front at low power settings. Some engines have limitations or restrictions on how power is applied during takeoff in strong tail or quartering winds, because of initial flow disruptions at the front from air ...


3

What you propose is used as a dust filter for helicopter engines, but even there the plug is not variable. Instead, air spills over the rounded edges of the intake if less is needed. Intake vanes never close to a point where they would block the intake; instead, they direct the flow such that it hits the compressor blades at the desired angle of attack. ...


3

For a compression system operating in normal condition, a mass-flow reduction leads to an increase of pressure rise. By reducing continuously the mass-flow, you reach the point of maximum pressure ratio after which the compressor operates differently. This could bring aerodynamic stall in flow and degrade performance. Rotating stall (often called stall) is ...


3

The reason comes down to the principle of operation of the compressors - a centrifugal compressor, as it's name implies, just spins around really fast, and the centrifugal force compresses the air. As you can see in the image below, the vanes of the impeller of a centrifugal compressor just help push the air around in a circle (unlike an airfoil) and ...


3

This is the result from the simple momentum balance. In order for the propulsor to produce thrust, the exit speed after the propulsing element ($v_e$) must be higher than the incoming speed ($v$): $$T=\dot{m}(v_e-v)$$ where $\dot{m}$ is the total mass flux through the propulsor. So the correct way to read the efficiency formula is: the closer the exit ...


2

It is a very large question and it will be difficult (even with all information) to give a strict answer. Both LEAP-1A (A320neo family) and CFM56-5B (A320ceo family) are turbofan engines which means they have two cores (HP and LP core) and two flows, and where total airflow is created by a Fan. As you said, LEAP-1A has a larger diameter allowing higher by-...


1

There are really two things about this experiment, one is good science (if of dubious practicality), the other bad. To take the bad first, the experimental setup is extremely crude and the thrust measurement/calculation inaccurate. There are far better ways to measure thrust. Another answer has commented on this. From this perspective, the experiment is ...


1

No, it's not measuring thrust. It might be measuring a proxy for thrust density (force per unit area). Anybody could use their setup to measure a ducted fan or a turbojet or even a rocket, but nobody does. They themselves could have calibrated their rattling-ball instrument with a conventional thruster of known, conventionally measured, thrust (a $20 ...


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