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).
Calculations of comparative gas and wheel velocities at the inlet guide vanes during testing.
| Identifier | ExFiles\Box 42\3\ Scan048 | |
| Date | 1st December 1926 guessed | |
| contd :- o3o With this width there will be no interference. We can then gradually open out the throats tax till we find the width that gives us the best efficiency. (2) Inlet guide vanes. We give below comparative gas and wheel velocities at the inlet guide vanes, calculated from figures obtained during test. R.P.M. = 20,000 Absolute pressure in eye of blower. = 11.2 lbs/sq.in. Temperature in eye of blower = 10°C. Density at eye = (144 X 11.2) / (96 X 283) = .0592 lbs/cu.ft. Air delivery = 49 lbs/min. Volume per min. passing through guide vanes = 49 / .0592 = 827 cu.ft. Vane area normal to flow = 7.5 sq.ins. Velocity in guide vanes = (827 X 144) / (60 X 7.5) = 265 ft/sec. Vane angle = 45° Resolved velocity in plane of wheel = 265 cos 45° = 187 ft/sec. Wheel velocity at outer circumference of guide vanes = (20,000 X 4.5 X 3.142) / (60 X 12) = 393 ft/sec. Wheel velocity at inner circumference of guide vanes = (20,000 X 1.75 X 3.142) / (60 X 12) = 153 ft/sec. contd :- | ||