Re: Water injection ?

From:         alexandc10@aol.com (Alexandc10)
Organization: America Online, Inc. (1-800-827-6364)
Date:         31 Oct 95 00:31:29 
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"water injection" actually refers to a solution of water and methanol,
injected in a finely atomized spray into the engine's intake zone.  This
helps performance in the following way:  The atomized spray evaporates
immediately, absorbing heat (585/cal/gm3) and effectively lowering the
temperature of intake air.  Lower temperature air is denser than higher
temperature air.  Turbine engines provide greater thrust, at lower
internal temperatures, when provided with denser ambient air.

H20/meth is quite effective, however it is expensive, and also corrosive.
It can only be used during take-off.  It is not seen on more modern
aircraft, as modern powerplants have sufficient power.  The 707 (have you
ever watched a 707 take off roll at gross weight?) was essentially
underpowered.

Alex