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).
Carburetter petrol flow velocity, including a formula and a corresponding graph.
| Identifier | ExFiles\Box 66a\1\ scan0074 | |
| Date | 26th November 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. -2- Expl. No. REF:HS{Lord Ernest Hives - Chair}/ACL/LG26.11.25 through the carburetter also govern the amount needed. The following example will illustrate the point. The velocity of petrol flow (v) may be expressed by the following formula :- v² = Wo/w v₀² - 2 gh. { v₀ = vel. of air flow. { Wo = density of air. { w = density of petrol. { h = level of petrol below jet. This equation is not strictly true as it takes no account of the change of density of air and gain or loss of heat but is a close approximation used for the sake of simplicity and from it the following curve has been drawn. This curve shows how the richening tendency is far more marked at low speeds. GRAPH: Title: PETROL DELIVERY FOR VARIOUS AIR VELOCITIES. Table: PETROL LEVEL .450" | SP.{Mr Spinney} GR{George Ratcliffe} PETROL .75. Y-axis: PETROL VEL. FT/SEC X-axis: AIR VELOCITY FT/SEC Caption: OBTAINED FROM THE ABOVE FORMULA. | ||