Flow Circuit with Valve and Series Flow Resistance
by S. Gabel and M. Brandemuehl  Revised for TRNSYS by N. Blair and R. Schwarz

      	This model was adapted strictly for use with the TRNSYS Program by
the Solar Energy Laboratory.

	The algorithm calculates fluid flow rate through a valve or damper (a
variable flow resistance) in series with a fixed flow resistance.  The flow rate
is determined as a function of valve position using the definition of valve
authority.  Given the valve authority and the flow characteristics of the fully 
open valve, the flow rate is determined directly as a function of valve 
position, eliminating the need to perform detailed system pressure balances.
The major restriction for application of the algorithm is that the total 
pressure drop across the pair of series components must be constant with 
changing valve position.  It is particularly will-suited to flow take-offs from
larger loops.
	Sample inputs and outputs are located in the source code.

REF:  A Toolkit for Secondary HVAC System Energy Calculations  May 25,1992
      Joint Center for Energy Management  Univ. of Colorado at Boulder