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).
Tests on engine cooling systems, focusing on header tank design, water flow, and steam formation.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan169 | |
| Date | 15th January 1931 | |
| - 2 - (e) That even when the header tank is so arranged that the cylinder jackets are full before starting, there is a displacement takes place with the rise in temperature indicating a poor water flow over and around the liners allowing steam to form locally. If steaming could be reduced to a minimum by improving water flow in the jackets (experiments are in hand with this object in view 'Wg{Mr Gill - Financial Director}/Ten2/MS.15.1.31!) then a large header tank would not be required and the advantages gained would be increased reliability of engine and installation and the saving of a considerable weight to the aircraft. Header tanks required for the 'Hart' and 'Fury' machines are unreliable if they are below a total capacity of 5.1 gallons irrespective of tank design, whereas on a French machine having a 'Hispano' engine, the total capacity of their header tank is only .55 gallons (4.4 pts.) and gives satisfactory results up to 100°C, and with the "F" engine accommodation has to be found for the displacement of 53% of the water from the cylinder jackets over and above the reserve water. The sequence of the tests made are as follows and are described later:- Test (1) To find the variation of the air space in the cylinder jackets relative to the position of the header tank, and when the system is tilted at varying angles. (2) To find the effect on the water level in the tank when the engine starts up. (3) To what extent the water level is affected by the temperature rise. From test (3) it was found that water was displaced. (4) To find if the position of the tank had any influence on the formation of steam in the cylinder jackets. DESCRIPTION OF CURVES AND TESTS MADE. TEST(1) From the curves and sketches appended, it will be seen that the air space in the cylinder block varies with the angle of inclination and the relative position of the header tank. Curve 200 F.{Mr Friese} The greater the angle of inclination and the lower the tank is mounted the greater the air space in the cylinder blocks. When the engine starts, the quantity of water required to fill this air space is drawn from the header tank thereby reducing the level in the tank by that amount. From Curve 200 F.{Mr Friese} it can be ascertained the air space in the cylinder blocks from the various water levels in the header tank at different angles. contd. | ||