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).
Page 2 of a report detailing nozzle discharge trials with petrol, including a data table and summary of findings.
| Identifier | ExFiles\Box 36\1\ scan 048 | |
| Date | 23th May 1917 guessed | |
| (2) Contd. Nozzle Bore. Length Length:bore ratio Average coeff: of discharge observed. C1 8 80 10.0 .825 C2 8 128 16.0 .81 C3 8 176 22.0 .80 C4 8 224 26.0 .78 D1 12 128 10.7 .825 D2 12 176 14.7 .82 D3 12 224 16.7 .81 D4 12 288 24.0 .80 The liquid used was petrol and the nozzles were allowed to discharge with their axes in a horizontal direction. The following paragraphs summarise the results of these trials:- (1) For a given nozzle, the variation of discharge with head follows the usual law of being very approximately proportional to the square root of that head. (2) For nozzles in which the length bore ratio was about 10 or less as in cases A1, B1, D1, the coefficient of discharge was approximately .825, i.e. the same as for a short cylindrical orifice discharging water. This shows that the effect of skin friction in such nozzles is practically negligible and that comparison of discharges is practically merely by areas. Contd. | ||