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 and tests to overcome water flow reversals in the 'Kestrel' 25 engine's water system.
| Identifier | ExFiles\Box 179\2\ img023 | |
| Date | 8th December 1931 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Fkn. c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to Rg.{Mr Rowledge} c. to Ly. L. ORIGINAL Hs{Lord Ernest Hives - Chair}/Fkn.1/MJ.8.12.31. x2965 x3866 REVERSALS OF WATER FLOW ON 'KESTREL' 25 WITH TWO-PIECE CYLINDERS. It was found necessary to modify the water system of the supercharged 'Kestrel' engine running under evaporatively cooled conditions, in order to overcome the reversals of water flow which occurred if the engine was throttled back quickly. These modifications which were recommended for the type test on 'Kestrel' MS-39, included a more efficient circulating pump, larger top water rails and outlet elbows, an extra pipe leading from the centre of each cylinder block to the top water rails, and 13/16" dia. restriction washers between the horn pipes and the cylinder block. (Ref: Hs{Lord Ernest Hives - Chair}/Gib.1/AD27.6.31) The behaviour, as regards reversals of flow, of the detachable head 'Kestrel' engine under evaporatively cooled conditions, has recently been investigated in accordance with Re/Tsn.1/DM.{D. Munro}23.10.31. CONDITIONS OF TEST. The following details were general to all tests - Engine. - 'Kestrel' ll's-25 with two piece cylinders and increased capacity water pump to LoP.E37267 DRS.1516. Restriction washers 3/4" dia. fitted at rear cylinder outlets. Water inlet and outlet temperatures maintained at 100°C. The outlets from the engine were led into a 'Buzzard' header tank, of the type used in steam cooled installation, situated at the same height above the pump. A gauge glass and pendulum type flow indicator were inserted in the pipe between the base of the tank and the pump inlet. Pressures were taken at the pump inlet and at various points in the cylinder block. Temperatures were taken at the pump inlet, engine outlet and in the header tank. The steam from the header tank was carried to waste and the loss made up by feeding water into the header tank. In taking the speed at which reversal occurred, the engine was run at 2250 R.P.M. and 385 BHP. (i.e. 90% of Ground Level Power) until all conditions had become stabilised and then the throttle was closed at a standard rate i.e. allowing 4-5 secs. to close from 2250 RPM. to S.R. speed. when reversal occurred the engine speed was checked. | ||