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).
Modifications made to a tank to prevent water surging and spilling.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan104 | |
| Date | 7th January 1931 guessed | |
| - 2 - MODIFICATIONS TO TANK. The tank as received from Hawkers is shown in Fig.1. on the sketches attached herewith. Connecting to the engine top water rails is a horned pipe which leads into a common pipe inlet to the tank. This pipe finishes flush with the bottom of the inside of the tank. A "pent roofed" baffle was fitted the full length of the tank to:- (1) Break up the surging of the water. (2) For supporting the tank internally. The vent was dome-shaped but not spherical as we re-commend and had a baffle plate fitted over the bottom of it, drilled for venting. The intended capacities were 2.5 gallons water and 2.8 gallons air space. The total tank capacity being 5.3 gallons. Other than the baffle no attempt had been made to direct the water flow inside the tank which is the most important feature to avoid 'spilling', and tests proved this tank to be very bad in this respect. Hawkers arrangement was removed and we applied the principle adopted (proved) in the 'Fury' header tank. Fig.II. i.e. directing the water flow to the top of the tank and then by means of a tray (sealed on three sides) on to the rear wall of the tank. The vent remained as before. This scheme was not successful in this case owing to the shallowness of the tank compared with the 'Fury' tank. Also on the 'Hart' tank the back is at right angles to its floor whereas the 'Fury' tank back is inclined which would have a 'slowing up effect' or further changing direction of the water flow (see Fig. IV.) By introducing the R.R. vent the 2" spherical type had no effect on the 'spilling'. By changing the direction of the flow of water, using two pipes instead of one as in Fig.III. introduces the scheme proved in the R.R. Tank and was also successful in this case and was adopted. WATER LEVEL. The tests were carried out trying to maintain the in-tended 2.5 gallons reserve water in the tank (although tests were also carried out with less to note the effect.) With the R.R. internal arrangements (Fig.III.) and using 2.5 gallons reserve water (or cold filling level) the water loss was greatly reduced between 90 and 100°C, but the loss was such as to render the tank unsatisfactory in our estimation, and it was found that by reducing the 'cold filling level' from 2.5 to 2.0 gallons no water loss was experienced under the most severe conditions. contd. | ||