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).
Test report on the Falcon X supercharger, detailing test conditions, results, and an impeller failure.
| Identifier | ExFiles\Box 42\3\ Scan014 | |
| Date | 15th October 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/AR. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} X3841 Hs.{Lord Ernest Hives - Chair} away. Hs{Lord Ernest Hives - Chair}/AR/LG15.10.26. FALCON X - SUPERCHARGER. H4550 X.3841 Test conditions. The supercharger was tested on a rig. Power input was measured from the torque reaction on the supercharger casing and its characteristics were obtained by restricting the air flow to the carburetter, and discharging at approximately atmospheric pressure. Air measurement was by means of a calibrated venturi. A Claudel Hobson carb. was fitted with 56 mm. chokes. Results. These are given in the attached curves. The efficiencies obtained at 20,000 r.p.m. are higher than obtained on the previous supercharger, but are still about 15% low. The difference between the total efficiency and adiabatic efficiency curves gives the mechanical losses in the supercharger. The results obtained at 18,000 r.p.m. show greater promise, but we were unable to complete the series of readings owing to a blade breaking off the impeller. The attached sketches show the slight differences exist between the diffuser as made, and as recommended by Mr. Ellor of the R.A.E. The mean axis of the passage between adjacent vanes now makes an angle of 11.5° with the tangent to the rotor, as compared with 9.7° recommended. The width of this passage is now 0.234" at the neck, as compared with contd:- | ||