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).
Analysis of power curves and blower efficiency, proposing a modified blower design for an 8-cylinder engine.
| Identifier | ExFiles\Box 140\1\ scan0098 | |
| Date | 20th December 1934 | |
| -2- Hs{Lord Ernest Hives - Chair}/Smth.9/KW. 20.12.34. From these curves it will be seen that at 3250 r.p.m. a boost ratio of 1.23 is claimed to raise the power 34%. We have checked the boost pressure curve by measurements on the Graham car and consider the power increase to be highly improbable. Possibly the two power curves do not refer to otherwise identical engines. With regard to the blower efficiency, rig tests have shown that the Graham blower is only some 35% efficient at the working points. The rotor is a rough casting, there is excessive rotor clearance and no diffuser. We shall soon be testing a machined all over rotor with reduced clearance, and Hs{Lord Ernest Hives - Chair}/Aln. has schemed out a suitable blower incorporating a diffuser with an estimated efficiency of 60%. The diffuser, of course, involves a greater overall diameter, and before we construct this blower we shall want to know whether or not there is room for it on the proposed 8-cylinder engine. Hs{Lord Ernest Hives - Chair}/F.Ll.Smith. | ||