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Euler number (physics)

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(Redirected from Ruark number)

The Euler number (Eu) is a dimensionless number used in fluid flow calculations. It expresses the relationship between a local pressure drop caused by a restriction and the kinetic energy per volume of the flow, and is used to characterize energy losses in the flow, where a perfect frictionless flow corresponds to an Euler number of 0. The inverse of the Euler number is referred to as the Ruark Number with the symbol Ru.

The Euler number is defined as

where

  • is the density of the fluid.
  • is the upstream pressure.
  • is the downstream pressure.
  • is a characteristic velocity of the flow.

An alternative definition of the Euler number is given by Shah and Sekulic[1]

where

  • is the pressure drop


See also

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References

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  1. ^ Shah and Sekulic, Fundamentals of Heat Exchanger Design, John Wiley & Sons, Inc. 2003

Further reading

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  • Batchelor, G. K. (1967). An Introduction to Fluid Dynamics. Cambridge University Press. ISBN 0-521-09817-3.