Related Resources: calculators

Compressible Flow through a Constriction Equations and Calculator

Compressible Flow through a Constriction Equations and Calculator

Figure 1 depicts compressible fluid flow through a constriction in a conduit. The various parameters are shown at point 1 in the larger section and point 2 in the smaller section. This configuration is similar to the convergent nozzle (Fig. 2), but it differs because the cross section at point 1 is generally not large enough to neglect velocity v1.

Compressible flow through a constriction.
Figure 1, Compressible flow through a constriction.

Convergent nozzle.
Figue 2, Convergent nozzle.

Preview Compressible Flow through a Constriction Calculator

The weight flow rate for compressible flow through a constriction can be determined from the equation

Eq. 1

G = A 2 1 ( p 2 / p 1 ) 2 / k ( A 2 / A 1 ) 2 2 g k k 1 p 1 γ 1 [ ( p 2 p 1 ) 2 / k ( p 2 p 1 ) ( k + 1 ) / k ]

Eq. 2

A n = π ( d n 2 ) 2

where

G = weight flow rate, lbs/ft2, (N/m2)
d1 = inlet area diameter, ft, (m)
d2 = inlet area diameter, ft, (m)
A1 = inlet area, ft2, (m2)
A2 = constriction area, ft2, (m2)
g = acceleration of gravity, ft/sec2 (m/sec2)
k = specific heat ratio
p1 = pressure inside the tank, lbs/ft2, (N/m2)
p2 = pressure inside the tank, lbs/ft2, (N/m2)
γ1 = specific weight of fluid inside the tank, lbs/ft3, (N/m3)
R = Gas constant, ft/°R, (m/K)

Schaum's Outline of Fluid Mechanics and Hydraulics

Related