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 discussing crankshaft stiffness and analysis methods.
| Identifier | ExFiles\Box 63\4\ scan0081 | |
| Date | 30th September 1929 | |
| G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 16/859. When Telephoning with regard to this letter please ask for Extension Number......20....... X4499 TELEGRAMS: Ballooning, South Farnborough. TELEPHONE: 108 North Camp, 361 Aldershot, & 103 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: E4/1179/15. YOUR REFERENCE: Hs{Lord Ernest Hives - Chair}/Tsn.1/MJ. ROYAL AIRCRAFT ESTABLISHMENT, SOUTH FARNBOROUGH, HANTS. September 30th. 1929. S.S. Tresilian Esq., Messrs. Rolls Royce Ltd., Derby. Dear Mr. Tresilian, 9026. I was pleased to get your letter of the 3rd. instant with its very full information concerning crankshaft stiffness. I have been awaiting the opportunity of reducing the figures to a non-dimensional basis and then examining the effects of the differences between the shaft proportions. A start has been made on this. It is possible that the outcome of the investigation will be an improvement in the formula, but one cannot be sure. Another thing that requires to be done is to apply the methods developed by Mr. Constant to the new shafts given in your letter and see how closely the results agree with your test results. I presume that you have a copy of Mr. Constant's report (R and M No.1201) which was published recently. On p.323 of the Journal of the Royal Aeronautical Society for April 1927, you will find that I have set out a comparison between the results obtained from the "Equivalent parallel rod" and "Equivalent flywheel" methods of computing natural frequencies. As the discrepancy is 20% in the case cited I think it important to determine why the simpler method gives / | ||