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).
Letter from the Royal Aircraft Establishment comparing calculations for torsional vibration.
| Identifier | ExFiles\Box 63\4\ scan0069 | |
| Date | 9th March 1929 | |
| G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 16/859. When Telephoning with regard to this letter please ask for Extension Number 20 TELEGRAMS: Ballooning, South Farnborough. TELEPHONE: 108 North Camp, 361 Aldershot, & 108 Farnborough. All Stores to be addressed:— R.A.E. Siding, Farnborough Station, Southern Railway (L. & S. W. Section). All communications to be addressed to The Chief Superintendent. OUR REFERENCE: E4/1179/30. YOUR REFERENCE: Hs{Lord Ernest Hives - Chair}/SS{S. Smith}1/T ROYAL AIRCRAFT ESTABLISHMENT, SOUTH FARNBOROUGH, HANTS. (March) 9th.1929. ? April S.Tresilian Esqre., c.o. Messrs.Rolls Royce Ltd., Derby. Dear Mr.Tresilian, Torsional Vibration 5939 I have compared the calculations you were good enough to give in your letter of March 28th. with my own calculations and find that there are still some obscure points of difference. Enclosed is a print of Sketch No.M.3751, which is a copy of the information supplied by Messrs.Rolls Royce and upon which my calculations have been based. I took 'b' to be the half length of a short journal and allowed for extra lengths by the method you mentioned. The information given in example 4 (shaft 16.c.) led me to take the "nose" length to be 0.925" of 1.5" outside diameter shafting, whereas you give 4.75" "nose" length, which accounts for the differences in the test stiffness values for one crank. I cannot reconcile my calculated stiffness per crank for this case, i.e. 1.53 million pounds inches per radian, with your value of 1.45 millions; my working is as follows :- 1-9-1. Dimensions / When replying, mention which period. | ||