THE EXPERIMENTAL AND ANALYTICAL DETERMINATION OF FLOW CHARACTERISTICS OF PNEUMATIC RESISTANCES.
Abstract
The paper presents an experimental and analytical method of determining the set of curves, representing flow characteristics of pneumatic resistances. The flow characteristics determined by means of this method give the relationship between the intensity of air flow and the pressure drop and the resistance over the full range of pressures encountered in pneumatic control devices. Analysis of various formulas and laboratory measurements lead to the conclusion that the most convenient formula for the pneumatic resistors is the equation for quantity of flow in long pipes. The formula is obtained on the assumption that friction is not neglected and so it gives a very good approximation of experimental results. Using this formula, it is often possible to obtain all the curves of the flow characteristic from one measurement of flow quantity under particular conditions. Dimensionless coordinates, which are used here, provide a considerable simplification of analysis because, one universal characteristic is obtained for all resistances. Flow characteristics depend not only upon the diameter and length of the throttling resistance but also surface roughness, the inlet and outlet, etc. In some cases, therefore, special corrective factors must be introduced into the universal characteristics. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 23, 1966
- Accession Number
- AD0635835
Entities
People
- Lech. M. Kaminski
Organizations
- National Air and Space Intelligence Center