Teledyne HFM-300 Automobile Parts User Manual


 
Manual: 151-082010 300-302 Series Page 20 of 31
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0 5 10 15 20 25 30 35
Flow (liter/min)
Passage Thickness (cm)
Fi
g
. 3.5
Thickness of the annular ring as a function of flow rate
for a sensor with a 75 Pa drop and a 2 cm spacing.
Each shunt must have a section of the annular region upstream of the upstream sensor tap to allow the
flow to become fully developed before reaching the first tap. The entry length for the annular passage
is then:
()
πτμ
ρ
40
rQ
L
e
Δ
=
Below is a graph that demonstrates the entry length that would be required to design a flow divider for
various full scale flows. The parameters on the sensor that the flow divider must match are the same
as the ones on the previous graph.
Entrance length as a function of flow rate
for an annular ring of the size specified in figure 3.5.
(3.8)
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0 5 10 15 20 25 30 35
Flow (liter/min)
Entrance Length (cm)
Fig. 3.6