elements.catalog.loss

elements.catalog.loss(
    K,
    name='loss',
    ref_port=0,
    eps=None,
    l_up=0.0,
    l_down=0.0,
    end_correction=0.0,
)

A concentrated total-pressure loss Pt_in - Pt_out = K * (1/2 rho u^2).

The element conserves mass and drops total pressure by K dynamic heads, with the head’s sign tracking the flow direction so reverse flow reverses the drop. The static state on each port is reconstructed from that port’s own area, so the loss may straddle an area change: the result is an isentropic area change (Pt-preserving static<->dynamic conversion) with the concentrated K-loss superposed.

Parameters

Name Type Description Default
K float Loss coefficient, referenced to the dynamic head at port ref_port. required
name str Element name. 'loss'
ref_port int Which incident port’s area and velocity define the reference dynamic head 1/2 rho u^2 that K multiplies – 0 (default, the upstream edge in the canonical orientation) or 1. Only matters when the ports carry different areas; tabulated K values always name their reference section, so set this to match the source. 0
eps float Per-element smoothing-width override (see ElementSpec.eps). None
l_up float Optional storage lengths [m] (default 0): an orifice’s thickness / backing length (compliance + inertance) and its end correction (inertance only). See :func:isentropic_area_change. With these the loss becomes an orifice impedance Z = R(u) + i*omega*L_eff/A (the steady resistance from J_alg, the reactance from M). 0.0
l_down float Optional storage lengths [m] (default 0): an orifice’s thickness / backing length (compliance + inertance) and its end correction (inertance only). See :func:isentropic_area_change. With these the loss becomes an orifice impedance Z = R(u) + i*omega*L_eff/A (the steady resistance from J_alg, the reactance from M). 0.0
end_correction float Optional storage lengths [m] (default 0): an orifice’s thickness / backing length (compliance + inertance) and its end correction (inertance only). See :func:isentropic_area_change. With these the loss becomes an orifice impedance Z = R(u) + i*omega*L_eff/A (the steady resistance from J_alg, the reactance from M). 0.0
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