Sierra 240-VTP, 241-VTP instruction manual Calculations for Liquid

Series 24-HP Instruction Manual Appendix C Fluid Calculations

Calculations for Liquid

Use this formula to determine the settings for “Goyal-Dorais” selections

and “Other Liquid” selections entered in the Fluid Menu. The liquid cal- culations were taken from Richard W. Miller, Flow Measurement Engi- neering Handbook (Second Edition, 1989).

Density

The liquid density is found using the Goyal-Doraiswamy Equation. Goyal-Doraiswamy uses the critical compressibility, critical pressure and critical temperature, along with the molecular weight to find the density. The equation for specific gravity is:

G			pc Mw 		0.008			T f 
	F	=				−			
			T		Z 0.773
							0.01102T 
			c		c			C 

The specific gravity can then be converted into density.

Viscosity

The liquid viscosity is found by Andrade's equation. This uses two vis- cosities at different temperatures to extrapolate the viscosity.

Andrade's equation:

∝	= AL exp		BL
			T
			deg R
To find A and B
B	= Tdeg R1Tdeg R 2 ln(∝1 / ∝2 )
L		Tdeg R 2 − Tdeg R1
AL	=	∝1
		exp(BL / Tdeg R1 )

The temperatures are all in degrees Rankin. Do not believe the subscript

R means they are reduced temperatures.

IM-24-HP C-3