Air Intake Not Rotating

csper · February 24, 2018

Hi, air intake fan is not rotating..

FragBum · February 24, 2018

i know right even the wheels on vehicles don't seem to rotate,.. :P:D

AlphaOneSix · February 24, 2018

I'm pretty sure, and I know someone will correct me if I'm wrong, but...

Those aren't supposed to rotate, it's the inlet guide vanes you see, not the first stage of the compressor.

Ramsay · February 25, 2018

That's interesting. When the engines are running it appears that this is actually the static compressor inlet, but when you shut the engine down and the rotation slows, it's clearly visible that the static compressor inlet is missing and the first stage of the compressor is visible which is rotating.

The inlet guide vane pitch is variable (0-35°), AFAIK when the engine is stopped they should be angled and at full power - edge on, to the air flow.

Looks like BST might have animated the IGV's but the animation has the open/closed stages mixed up?

However, I can't even see the IGV's in 2.5 with deferred shading. So I guess I should say well done to the OP for finding the correct sun angle where he can see them using F2 but can't help thinking he's nit picking.

For the J85-GE-13 (T-38 ) engine, the IGV's are linked to the inter-stage bleed valves and are full open (0°) when the bleed valves are fully closed (and vice versa)

Although the J85-GE-21 bleed schedule is likely different, IMHO it's unlikely the F-5E's IGV's are closed (35°) at full power as shown in the OP's picture.

The compressor has variable inlet guide vanes which are mechanically linked to the interstage (3rd, 4th, and 5th) bleed valves so that the vanes are deflected the greatest when the valves are fully open.

The inlet guide vane-interstage bleed schedule is a function of the inlet temperature and corrected engine speed.

Normally the bleed valves are scheduled from full open at 80 percent corrected speed to full closed at 94 percent corrected speed.