Print from Airliners.net discussion forum
http://www.airliners.net/aviation-forums/tech_ops/read.main/326957/

Topic: Inlet Flow Distortion And Inlet Vortex
Username: surajit001
Posted 2012-12-21 11:47:29 and read 2713 times.

I really want to know the concept of inlet flow distortion. Please can anyone explain me the concept in a simple way? Also, how is inlet vortex formed?

Topic: RE: Inlet Flow Distortion And Inlet Vortex
Username: jetlife2
Posted 2012-12-21 12:10:36 and read 2701 times.

Imagine a stream of water in a channel flowing uniformly. This is undistorted flow. Now imagine the stream stops and starts. Now imagine also a block placed at the edge of the stream. Now the flow behind the block contains eddies, and swirls and is not constant with time.

The stopping and starting is wind gust variation. The block at the side creates an effect like the edge of the inlet, when the wind approaches from the side. The front of the engine sees eddies, swirls (turbulence) and non-constant (unsteady) flow.

Engines are tested to demonstrate resistance to this. And they are often tested with a screen to eliminate this distortion, when it is specifically important to have uniform inlet conditions. See here at 1:20

http://www.youtube.com/watch?v=tT5EZ5itYH4

The most common type of inlet vortex is formed when the inlet is near enough to the ground that the inlet flow coupled with a crosswind shear flow forms a vortex. There must be shearing (cross flow) to initiate a vortex. Just like a tornado is formed by shear flow. See here

http://www.youtube.com/watch?v=_5vjq38CAj0


The messages in this discussion express the views of the author of the message, not necessarily the views of Airliners.net or any entity associated with Airliners.net.

Copyright © Lundgren Aerospace. All rights reserved.
http://www.airliners.net/