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<< Click to Display Table of Contents >> Slip coefficient by PFLEIDERER |
  
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<< Click to Display Table of Contents >> Slip coefficient by PFLEIDERER |
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Reduced energy transmission is expressed by decreased output coefficient p:
This coefficient can be empirically calculated in dependence of experience number ψ':
static moment from leading to trailing edge
experience number
experience number a: |
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Centrifugal impeller |
with guided vanes |
a = 0.6 |
with volute |
a = 0.65…0.85 |
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with plain diffusor |
a = 0.85…1.0 |
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Mixed flow/axial impeller |
a = 1.0 …1.2 |
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(the numbers are valid for sufficiently high Re; ψ’ strongly grows with small Re) |
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More descriptive is the decreased output factor kL:
(kL=1: for flow congruent to blade)
Circumferential component of the flow, which is congruent to blade, can be calculated as follows:
Now the outflow (slip) coefficient γ according to Wiesner can be calculated:
