1
$\begingroup$

Anybody knows the name of this intake? look at the bellow images:

enter image description here

enter image description here

Why don't Airbus and Boeing use the conventional NACA inlet? Why did they invent this kind of intake? I can see some parts of these aircraft that the conventional NACA inlet are embodied in.

$\endgroup$
2
$\begingroup$

Those inlets don't require the NACA duct profile because the openings are presented toward the airflow, being on a sloping surface relative to the freestream. The NACA profile in those locations serves no useful purpose and is a probably less effective, if anything.

The NACA duct profile was developed for inlets on surfaces that are completely parallel to the airflow, like along the straight sides of a fuselage or nacelle, where the freestream flow just passes on by (like a static port you might say). They were developed as a low drag alternative to the traditional scoop projecting into the airstream that you would normally have to use in such a location.

The sides of the NACA Profile, induce a change in direction of the ram air free stream without any projections (it's thought that the sides of the ramp act like vortex generators and it's the vortices that "pull" the free stream down the ramp) so that ram air is drawn down the ramp to the inlet opening. On a sloping surface like a wing root fairing as in those pictures, the ram air is directly impinging on the opening (as if it was a scoop sticking out) and doesn't need any "airflow redirection tricks" like the curved sides on the NACA inlet ramp.

enter image description here

$\endgroup$
1
$\begingroup$

This answer says that it is the ram air inlet for the cabin air conditioning. My take is that they've changed the design from the NACA duct to make it open and close on demand. It is harder to make a variable NACA duct due to the curvatures involved.

$\endgroup$
1
  • 1
    $\begingroup$ Interesting! because in that answer the LH RAI is a conventional NACA duct but in new versions of A380 that I have posted its images in my question, the LH RAI intake is changed. $\endgroup$ – Roh Dec 23 '20 at 11:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.