Linear fluid resistance using switching valves and a tank
Abstract
An active linear fluid resistance is demonstrated using the switched capacitor concept from electronics. For the analogous fluid component, this requires using switching valves to alternately fill and empty a tank. Analysis shows that the equivalent linear resistance is directly proportional to the switching period and inversely proportional to the tank capacitance. For fluid components the linearity is restricted to those cases where complete filling and emptying is achieved. The time period required to insure linearity is derived in terms of fluid circuit variables. As a result there is a lower limit on the magnitude of resistance that can be obtained for a given fluid circuit. This magnitude depends on circuit component values as well as on the desired operating pressure range. However, the net result is that we may construct a linear fluid resistance that has no dependence on orifice sizes, discharge coefficients or Reynolds Number.
 Publication:

20th Anniversary of Fluidics Symposium
 Pub Date:
 1980
 Bibcode:
 1980asme.symp...17K
 Keywords:

 Flow Resistance;
 Fluid Switching Elements;
 Linear Systems;
 Tanks (Containers);
 Circuit Diagrams;
 Oscillators;
 Performance Tests;
 Valves;
 Fluid Mechanics and Heat Transfer