Engines diagram
 

Hi,

Does anyone have a diagram that shows where are the vsv ( variable stator vanes?? no idea ...) located in the engines?

I trying to understand more about them...btw....are there other types of vanes in a jet engine?

from what i read so far, it seems they are used to direct/align air flow...that's pretty much all i know about vanes...:O

Many thanks.

Yes there are other types of vanes, one could write a book about how the various component work in the different jet engine types (Pure Jet, Low/High bypass etc).

I'd suggest you invest in Rolls Royces The Jet engine - Rolls-Royce The jet engine book, it'll tell you everything you need to know.

Neupielot

The vsv's you are asking about are generally in the forward portion of the compressor section in the engine. The vanes rotate (twist) to optimize the efficiency of the compressor across the operating conditions of the engine, not just the cruise condition. By being able to rotate (open or close) the stationary vanes, the total performance of the compressor can be optimized while maintaining acceptable stall margins.

There are other vanes in the turbine section of the engine which are fixed and do not rotate. The function of turbine stationary vanes (non-rotating airfoils) is to pick up the air from the trailing edge of the rotating turbine blades in front and redirect the air to enter the leading edge of the rotating turbine blades behind it at the proper angle.

Hope this helps your understanding.

TD

You may have had a typo. The vsv's control the angle of attack of airflow directed to stationary vanes (every other vane is variable attacking the stationary). They are designed to allow for the maximum amount of compression W/O stalling the airflow over fixed vanes. VBV's bleed the compression for the same effect. The VSV's are generally located in the compressor only and are every other blade to the fixed compressor vane.

Variable Stator Vanes... Job description
 

Variable Stator Vanes are generally used in the high stage compressor sections of Turbine Engines. Physical description would be that of a typical stator vane (or Stationary Vane) that is designed to rotate along its longitudinal axis and is controlled by any number of engine control units and typically pneumatically or hydraulically actuated. The purpose is to control the compressed air's angle of attack on the next compressor blade (rotor stage). This both increases the engines efficiency for a given speed/load and prevents compressor stalls via the ability to control blade/stage loading.
At least that is the way it's used on the aircraft I'm familiar with.
Cosmo

I'm with cosmo.

First 3 or so sets of stators in an multi stage axial flow compressor. The one right at the front before the first rotor is normally called the inlet guide vane and is often variable in pitch (to use the propeller term).

The primary goal of VSV's is to match pumping capacity of the front vs back end of the compressor. At low rpm, the front end tries to pump more air than the back end can handle, so the control system closes the front-end VSV's to re-match the stages.

And in so doing, the AOA of all the front-end airfoils is reduced to stall-free levels. Using a vector diagram, I could demonstrate this effect - reducing AOA on both rotor blades and stator vanes - but so far I have not found the vector diagram online.

This might help!