elements.catalog.linear_resistance

elements.catalog.linear_resistance(
    R,
    name='resistance',
    l_up=0.0,
    l_down=0.0,
    end_correction=0.0,
)

A linear flow resistance Pt_in - Pt_out = R * mdot (a quiescent acoustic resistance).

Drops total pressure in linear proportion to the through-flow mass rate, with the drop reversing with the flow direction. Because it is linear in the flow (not the quadratic dynamic head that :func:loss uses), it survives the linearization with a non-zero coefficient even at zero mean flow – the acoustic resistance of a screen, perforate or damper in an otherwise quiescent network, where the velocity-squared loss would vanish. In a flowing network it adds an ordinary linear (Darcy-like) total-pressure drop on top of the mean state. Mass is conserved and scalars (enthalpy, composition) pass through unchanged.

Parameters

Name Type Description Default
R float Resistance coefficient >= 0 in Pa per (kg/s): the total-pressure drop per unit mass flow. As an acoustic resistance it sets the linear damping Pt' = R * mdot'. required
name str Element label. 'resistance'
l_up float Optional storage lengths [m] (default 0): paired with R they make a screen / perforate / damper carrying both resistance and reactance – the quiescent orifice impedance Z = R + i*omega*L_eff/A (the cleanest inertance test, since it is linear and survives at zero mean flow). See :func:isentropic_area_change. 0.0
l_down float Optional storage lengths [m] (default 0): paired with R they make a screen / perforate / damper carrying both resistance and reactance – the quiescent orifice impedance Z = R + i*omega*L_eff/A (the cleanest inertance test, since it is linear and survives at zero mean flow). See :func:isentropic_area_change. 0.0
end_correction float Optional storage lengths [m] (default 0): paired with R they make a screen / perforate / damper carrying both resistance and reactance – the quiescent orifice impedance Z = R + i*omega*L_eff/A (the cleanest inertance test, since it is linear and survives at zero mean flow). See :func:isentropic_area_change. 0.0

Returns

Name Type Description
ElementSpec
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