Power gains with variable inlet guide vanes?

[Johansson]

In the excellent book "The gas turbine engine" by Jan P Norbye there is stated that having variable compressor inlet guide vanes would increase the power output by as much as 12%!

Water injection on the same engine with a PR and mass flows in line with our DIY engines was calculated to give a 10% increase.

Is variable guide vanes something that can increase the max power output of our engines with "modern" compressor designs, or was it just a way of increasing low- and midrange power output from older and less sophisticated compressor designs?



A combined 22% power increase with inlet vanes and water injection would mean a 30-40hp increase for my JU-01 turboshaft engine!

[racket]

Hi Anders

If only it was that easy .

Water injection will give gains but the engine needs to be designed with flow areas to accommodate the "steam", otherwise we only replace air with steam , also fuel burn rates increase a lot due to the latent heat of evaporation of the water .

As for variable IGVs for the comp , they're main benefit is for part power settings , they can reduce overall comp effic ( Ref bottom page 22 in my copy ) by ~4% .

Cheers
John

[Johansson]

Bugger.