From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Water system filling procedures and tests conducted at various engine inclinations for aircraft.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan170 | |
| Date | 15th January 1931 guessed | |
| - 3 - The range of curves are 7 1/2º, 15º & 20º inclination. Although 15º is the average angle of machines when at rest (i.e. of the Fighter and light Bomber class) an extreme angle of 20º was taken to meet possible future designs but chiefly to show what would be the result when filling a water system as used on a machine (shown in the sketch attached) when standing on uneven ground which might give an inclination approximating this angle. In the example given on Curve 200F. applied to the sketch of the aircraft, the air space in cylinder jackets at 20º would be 2.175 gallons. In consequence of this we would strongly recommend that if a water system is to be filled when the machine is on uneven ground, the attitude of the machine is such that the tail is resting on the highest point (see sketch 216F). This will reduce the angle of inclination and the risk of under filling. There are plenty of aerodromes where these conditions could be met with. The method employed in obtaining the data (Curves 199F. & 200F.) was by utilizing a pair of cylinder blocks fixed on a crankcase top half resting on a trestle (see sketch 218F.). The side water pipes were fitted and lead into a common pipe (on a level with the water pump position) from which another pipe was fitted to enable the system being filled. A gauge glass was fixed at the vertical centre line of the engine and connected to the lowest point of the side water pipes. Water was then carefully measured into the cylinder jackets and the level in the gauge glass measured from the crankshaft centre line, the procedure adopted for each inclination. The sharp bend in the curve (1) 199F. Engine Level, is caused by the filling of the topmost corners of the jackets just before commencing to fill the top water rails. TEST.2. In view of the fact that water was taken from the header tank to fill up the air space in the cylinder jackets when the engine started, tests were made to find if additional water was added equivalent to that amount required for the air space, whether the header tank would be satisfactory regarding spilling from the vent at high temperatures. Using a 'Fury' tank (which under the old conditions was an excellent one regarding non-spilling) and the engine tilted at 15º, a test was made starting from cold and warming up in the normal manner, it was found that at a normal temperature of 80ºC. water was ejected from the tank vent to the extent of 1.5 gallons which represented the amount required extra to fill up the air space. contd. | ||