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Units with rational exponents #46

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@DagBruck

For Modelica there is a discussion about introducing fractional exponents. See modelica/ModelicaSpecification#3012.

One such case is the valve flow equation:

w = Kv*sqrt(dp/(rho/rho0))

where w is the mass flow rate (kg/s), dp is the pressure drop (Pa = N/m2 = kg.m/(s2.m2) = kg/(m.s2)), rho is the inlet density (kg/m3), and rho0 is the reference density (cold water, also in kg/m3).

The unit of Kv is a bit weird: kg/s / (kg/(m.s2))^(1/2) = (kg.m)^(1/2)

Affects 4.4.2 Units of the specification.

Activity

  1. added this to the 2.1-alpha milestone on Mar 10, 2025
  2. removed this from the 2.1-alpha milestone on Dec 10, 2025
  3. pmai commented on Dec 10, 2025

    @pmai
    Collaborator

    F2F WS 2025-12-10: Currently this is not yet supported in FMI, which would make SSP support slightly more pressing in practical terms - given this situation, this is not seen as a high priority item for release 2.1.

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