Pressure drop 872 Pa (0.00872 bar) at 14.1 m³/h → Kv 151 m³/h (Cv 174) · Water through a pipe bend.ipt: internal flow, inlet 2 m/s, Water (20 °C)

LaminaroCFD · Laminaro add-in v0.46.0 · 2026-10-29 05:46:38Z UTC

Design: Water through a pipe bend.ipt as of 2026-10-29 05:39 UTC · a copy is kept with this run (design.ipt)

Kv (from the total-pressure drop)151 m³/h

Cv = 1.156 · Kv174

Pressure drop (total)0.00872 bar (871.9 Pa)

Flow rate14.1 m³/h (3.907 l/s)

Loss coefficient K = Δp ÷ ½ρv² (v: mean inlet velocity)0.4367

Good enough for engineering use. The pressure drop is steady within ±0.7 % (last 200 iterations); mass balance 0.00 %. The remaining unsettledness is mostly next to the walls.

Set-up

Part	Water through a pipe bend.ipt
Study	Example · Water through a pipe bend
Where the fluid is	Modelled fluid body (flow inside the part)
Fluid	Water (20 °C) (ρ 998.2 kg/m³, ν 1.004e-06 m²/s)
Inlet	2 m/s
Time behaviour	steady (mean values)
Turbulence	k-ω SST (automatic: Re ≈ 10·10⁴: turbulent)
Mesh level	Standard

Convergence

Pictures

What this result rests on

Good enough for engineering use. The pressure drop is steady within ±0.7 % (last 200 iterations); mass balance 0.00 %. The remaining unsettledness is mostly next to the walls.
One mesh only: mesh independence was not checked.
Steady RANS (k-ω SST): mean values. Vortex shedding, peaks and fluctuating loads are not resolved.
Stopped at iteration 312: converged (the pressure drop steady within ±0.7 % over 200 iterations, residuals low).

Notes

Mesh 514537 cells; values = mean of the last 10 % of 313 iterations.
Δp = area-averaged pressure inlet → outlet; K = Δp_total / (½ρU²) with the inlet velocity; Re = 9.96e+04 (hydraulic diameter 0.05 m).
Kv = Q · √((ρ/1000) / Δp) with Q in m³/h and Δp in bar: 14.1 m³/h through the part at a total-pressure drop of 0.00872 bar inlet → outlet (ρ = 998.2 kg/m³) gives Kv 151 m³/h; Cv = 1.156 · Kv = 174 (US gpm at 1 psi). A valve's datasheet Kv is usually measured between pressure taps in straight pipe upstream and downstream; this one is between the part's own openings.

Every number on this page comes from this run's own files (summary.json, the force-coefficient history, the solver log). The raw data is in the data folder. Print this page to PDF for a quick hand-out.
Run folder (for your files and for support): C:\Users\niels\Dropbox\Brain Vault\Brain\Projects\Laminaro\jobs\Water through a pipe bend · Example · Water through a pipe bend · run 1 2026-10-29 0639\results