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 discussing the principles governing the flow of a viscous liquid through an orifice.
| Identifier | ExFiles\Box 178\1\ img162 | |
| Date | 22th June 1926 | |
| - 8 - Hs{Lord Ernest Hives - Chair}/Rml/T22.6.26. (ii) Those which have substantially a fixed minimum loading obtained by a spring retained valve opposing the circulation of a liquid. As a matter of interest it may be observed that the most successful of type (i) employ a rotor radially disposed in a cylinder while those of type (ii) have almost exclusively adopted a piston working in a cylinder. These mechanical details, however, could be interchanged without affecting the principles at stake. (b) Principles governing the flow of a viscous liquid through an orifice. Three main principles govern the pressure required to force liquid through an orifice. (1) There is an energy loss when any liquid whether viscous or not, is forced through an orifice not streamlined as is a venturi. This energy loss is proportional to the square of the velocity of the liquid. A loss of energy means work done in this case. (2) With a viscous fluid, the pressure required to force the liquid through any passage is directly proportional to the viscosity of the fluid. (3) The pressure required to force a liquid through a passage is directly proportional to the quantity or velocity of the liquid. It will be observed that (1) and (3) are both affected by the speed at which the axle moves. Hence any hydraulic shock damper restrains rapid movements more than slow movements. This is on the whole desirable because violent axle movements that contd. | ||