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).
Investigation into fuel boiling and freezing problems with a Goshawk carburetter on a Kestrel engine.
| Identifier | ExFiles\Box 179b\3\ img043 | |
| Date | 17th January 1933 | |
| ORIGINAL To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Fns. c. Sg.{Arthur F. Sidgreaves - MD} Wsf. c. Rg.{Mr Rowledge} L. c. By.{R.W. Bailey - Chief Engineer} Rp. c. Lr.{Mr Ellor} Lp.{Mr Lappin} GOSHAWK CARBURETTER. INVESTIGATION OF FUEL BOILING AND FREEZING TROUBLE. WHICH WAS ENCOUNTERED ON KXP.3. CIVIL TYPE TEST ENGINE. During the Civil Type Testing of the Goshawk supercharger and carburetter on Kestrel engine No. KXP.3, considerable trouble and unstable functioning of the engine was occasioned due to freezing of the fuel in the diffusers and on the throttles, and also to flooding which was considered to be due to the fuel becoming overheated and boiling over, by an observed fuel flow of 500-600 pts/hr. after the engine had stopped. These observations were so persistent and so detrimental to the running of the engine during the duration of the type test (as to form a separate report to the Air Ministry from the A.I.D. condemning the carburetter on these points, as unairworthy)? Both the freezing and boiling troubles were observed under the same conditions, i.e. when running at the rated boost pressure at 2500 R.P.M. and at the 9/10 power position, so our investigations are mainly confined to these conditions, using D.T.D.134 fuel. Kestrel No.37 engine fitted with a Goshawk super-charger and carburetter to the same specification as KXP.3 engine, with the exception of the carburetter jacket outlet washer, (which had been fitted with a .093 orifice on KXP.3. instead of .125), was used for the tests and all tests were carried out under A.I.D. observation. The weather at the commencement of the tests being foggy and frosty with a Hygrometer reading showing 100% saturation was ideal for freezing tests, so these tests were investigated first, and took the form of endurance running at 2500 R.P.M. at 9/10 power, viz - 483 BHP. with an actual air intake temperature of 20°C. Twenty minutes running under these conditions showed no trace of freezing, the power output, boost, and fuel consumptions, which indicate freezing by varying considerably | ||