DekEn

อัปเดต 2026-09-07

Two-phase / marching

flashing / condensing

The rigorous marching engine integrates properties along each pipe — for flashing, condensing, or otherwise property-varying two-phase streams.

เมื่อไรจึงใช้
  • Vaporizing risers, condensing lines, evaporation duties, two-phase pipe segments.
ค่าที่ต้องกรอก
ค่าคำอธิบาย
Fluid & inlet stateA real fluid with a two-phase envelope; inlet P/T/quality.
Heat / ambientOptional ambient heat transfer along the pipe (U·ΔT per segment).
คำนวณอย่างไร

The pipe is marched in small steps. At each step we find the flow pattern and liquid holdup, evaluate a separated-flow friction gradient, and add the in-situ-density static head and the acceleration term from expansion — integrating pressure, enthalpy, and quality along the pipe.

สมการ
Pressure-gradient balance
G = mass flux, θ = pipe inclination. The three terms are integrated segment by segment.
In-situ (holdup) density
α = void fraction from the holdup correlation — this ρ, not the mixing-cup density, drives the static head.
Vapor quality
Mass fraction of vapour, updated by the enthalpy/flash along the pipe.
ข้อควรระวัง
noteFirst solve after a restart JITs the numba kernels (warmed on startup).
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