Originally Posted by
GlosMikeP
First of all, there is no value using water to cool a jet engine. You can't carry enough of it and it would be counter-productive anyway to have super-heated steam chasing around the airframe rapidly corroding everything in sight.
Mike, I don't believe anyone is suggesting cooling the engine externally, if this is what you mean. The Harrier system does work by injecting water into the combustion chamber and turbine inlet flow; this has the effect of cooling the exhaust gas flow permitting the addition of more fuel to allow the engine to spin faster and therefore develop more thrust. Arming the water injection system in the cockpit has the effect of rasing the JPT and RPM datums to their 'wet' values.
Hilife, thanks for your input. You summarise what I'd more or less concluded myself, that material, design and technology advances have more or less made water injection redundant on the latest engine variants.
Thank you all.