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).
General conclusion and a table of leading particulars for a Graham blower.
| Identifier | ExFiles\Box 140\1\ scan0062 | |
| Date | 23th July 1934 | |
| -4- Hs{Lord Ernest Hives - Chair}/Aln.1/WJ.23.7.34. Cont'd.{John DeLooze - Company Secretary} at the eye of the casing was seen to be rotating under the drag of the entering air. This is interesting as showing that the air begins to rotate before actually entering the rotor. ADAPTATION TO BENTLEY. We estimate that with a gear of about 5.35:1 the blower would operate very well on the Bentley engine giving a boost of about 4"Hg. at around 40% adiabatic efficiency. GENERAL CONCLUSION. The Graham blower is a well proportioned design and although it is rather inefficient it could not be much improved upon without increase of cost. It is not a mere selling feature but undoubtedly gives a useful increase in power in the engine to which it is fitted. We append a table of leading particulars of the blower - Rotor Diameter 7.5". No. of blades 12. Blade thickness 0.100". Hub diameter 2.0" Air inlet diameter 2.25 " approx. Air inlet area 3.15 sq.ins. approx. Tip axial width 0.100" approx. Tip area (incl. clearance) 3.04 sq.in. Ratio dia./width. 75:1 Volute exit area 3.14 sq.in. Volute exit dia. 2" Moment of inertia of rotor with shaft .0382 lb.ft.2 Mass = 2 lbs. 1 1/4 ozs. Radius of gyration = 1.62" Equiv. M.I. on crankshaft = 1.26 lb.ft.2 Hs{Lord Ernest Hives - Chair}/F.J.Allen. | ||