Normally, the (de-ionised) water is injected just upstream of the combustion chamber, but downstream of the compressor. It lowers *** (Turbine Inlet Temperature) and JPT (Jet Pipe Temperature), thereby allowing the engine to run at a higher RPM for any given ***/ JPT. There is also a very small thrust increase due to the water/steam in the flow, but the real purpose is to supress the ***.

I believe that with water/methanol injection, this was injected somewhere in the compressor stages, and the evaporation of the methanol caused the temperature of the air to drop, thereby inceasing it's density and mass flow rate, thereby increasing thrust. I don't think the methanol was burned directly.

As long as we are limited by bearing life and a physical compressor and turbine RPM limit, rather than running on the JPT limit, I don't see that we would be able to use any potential benefit of water injection. Interesting experiment though.

Paul