Commercial/industrial water/meth products

[jellydonut]

Did you know oil companies sell water/methanol mixtures made with conformance to industry and military standards?

Aviation Fuels - Grades and Specifications - Shell Aviation
Aeroshell Book
http://www.bp.com/liveassets/bp_internet/aviation/air_bp/STAGING/local_assets/downloads_pdfs/a/air_bp_products_handbook_04004_1.pdf

Methanol/Water Mixture 45/55
The power output of an engine is directly related to the mass or weight of the airflow passing through the engine, and thus, when operating under high temperature and/or high altitude conditions where air density is low, power is reduced. Under these conditions, the power output can be restored by the injection into the airflow of special power boost fluids, which are also known as thrust augmentation fluids.

These fluids have a high latent heat of vaporisation and act by cooling the airflow to raise its density and thereby increase the weight of the airflow through the engine. This technique can also be used to augment take off power under normal atmospheric conditions. The effect can be obtained using water alone but methanol can be added to the water to prevent freezing and also to provide an additional source of fuel.

The use of these fluids is steadily diminishing and, presently, Air BP supplies only one grade, namely Methanol/Water Mixture 45/55.

The methanol and water used must be of very high purity to prevent the formation of deposits in the engines. Methanol conforms to Specification BS 506 and the water, either demineralized or distilled, meets the UK Defence Standard and the Rolls Royce Specification. Details of the components and the Methanol/Water Mixture 45/55 are shown on the following table.

Applications

Modern gas turbine engines do not require the use of either water or water/methanol mixture. For certain older designs of engine, water alone is usually used but there are some engines which use methanol/water mixture, the most significant being the Rolls-Royce Dart turboprop engine.

SHELL POWER BOOST FLUIDS
It used to be commonplace for large piston engines to require special fluids to increase their take-off power. Similar injection systems are also incorporated in some turbo-jet and turbo-prop engines. The power increase is achieved by cooling the air consumed, to raise its density and thereby increase the weight of air available for combustion. This effect can be obtained by using water alone but it is usual to inject a mixture of methanol and water to produce a greater degree of evaporative cooling and also to provide additional fuel energy.

For piston engines, methanol/water mixtures are used and these may have 1 percent of a corrosion inhibiting oil added. The injection system may be used to compensate for the power lost when operating under high temperature and/or high altitude conditions (i.e. with low air densities) or to obtain increased take-off power under normal atmospheric conditions, by permitting higher boost pressure for a short period.

Both water alone and methanol/water mixtures are used in some gas turbine engines, principally to restore the take-off power (or thrust) lost when operating under low air density conditions. Use of a corrosion inhibitor in power boost fluids supplied for these engines is not permitted.

The methanol and water used must be of very high quality to avoid formation of engine deposits. The water must be either demineralised or distilled and the only adulterant permitted in the methanol is up to 0.5 percent of pyridine if required by local regulations as a de-naturant. In the past there were several different grades of water/methanol mixtures, e.g. 45/55/0 for turbine engines, 50/50/0 for piston engines (this was also available with 1% corrosion inhibiting oil and designated 50/50/1) and 60/40/0, however, with decreasing demand Shell now only supplies 45/55/0.

The UK MoD's Defence Standard on water/methanol:
http://www.dstan.mod.uk/standards/defstans/68/253/00000200.pdf

I don't know about you but 'thrust augmentation fluid' sounds nicer than water/meth. :evil

 

[roachie]

Where do we buy this though.

 

[jellydonut]

Where do we buy this though.

Shell's site says to 'contact them for purchasing' - I can only assume that a supplier of either Shell or BP aviation fuels would be able to supply this. I don't think it's a shelf item unless you're situated in an area where there's fleets of historical aircraft, or there's air racing going on.