Hot and cold water mixing in a tee.ipt · Example · Hot and cold water mixing in a tee · Run 2 · 2026-10-29
Pressure drop 1 160 Pa at 3.15 l/s
Hot and cold water mixing in a tee.ipt: internal flow, 2 inlets → 1 outlet, Water (20 °C) · outlet 32.09 °C
Converged · good enough for engineering useStandard mesh
Pressure drop (total)
1 160Pa
±0.22 %
Flow rate
3.15l/s
11.4 m³/h
Loss coefficient K
1.79
±0.22 % · Δp ÷ ½ρv², v = mean inlet velocity
Outlet temperature
32.1°C
SettledGood enough for engineering use. The pressure drop is steady within ±0.2 %, the flow through inlet 1 within under ±0.1 %, the flow through inlet 2 within under ±0.1 % (last 200 iterations); mass balance 0.00 %. The remaining unsettledness is mostly next to the walls.
Results in detail
Total-pressure drop, inlet → outlet
1 160 Pa
Static-pressure drop, inlet → outlet
1 730 Pa
Flow rate
3.15 l/s(11.4 m³/h)
Loss coefficient K = Δp ÷ ½ρv²
1.79
Flow per opening
Opening
Role
Flow [l/s]
Share of outflow [%]
Total pressure [Pa]
Inlet 1 (at x -300, y 0, z 0 mm)
inlet
1.96
2 250
Inlet 2 (at x 0, y 250, z 0 mm)
inlet
1.2
2 830
Outlet (at x 600, y 0, z 0 mm)
outlet
3.15
100
1 310
Pressure drop per path
Path
Total [Pa]
Static [Pa]
Inlet 1 (at x -300, y 0, z 0 mm) → Outlet (at x 600, y 0, z 0 mm)
937
1 750
Inlet 2 (at x 0, y 250, z 0 mm) → Outlet (at x 600, y 0, z 0 mm)
1 520
1 710
What this result rests on
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 387: the pressure drop is steady within ±0.2 % over 200 iterations; the residuals levelled off at about 2 × 10⁻², so parts of the flow keep moving (likely unsteady regions): fine for the pressure drop, not for the detailed flow pattern.
Pictures
Figure 1. Streamlines coloured by velocity; the walls coloured by their pressure.Figure 2. Velocity in a section along the flow path.Figure 3. The mesh the flow was computed on.
Convergence
Iterations
389 of 1 500 planned
Movement of the pressure drop
±0.22 % over the last 200 iterations
Mass balance (in vs out)
below 0.01 %
Final residuals
pressure 0.00765 · velocity 0.0149
Residuals measure how far the solver's equations are from being exactly satisfied in each cell; they shrink as the solution settles. Here they levelled off at about 1 × 10⁻² instead of below the usual 10⁻⁴, so the flow field may still change a little. The key result moved by ±0.2 % over the last 200 iterations, so it is settled.
Figure 4. Residuals per iteration (log scale, left). Low and flat: the solution has settled.
Hot and cold water mixing in a tee.ipt as saved 2026-10-29 10:41 UTC; a copy is kept with this run (design.ipt)
Notes
Mesh 530854 cells; values = mean of the last 10 % of 389 iterations.
Δp = flow-weighted total pressure of the inlets minus that of the outlets; per path: area-averaged inlet minus outlet. K with the mean inlet velocity; Re = 5.68 × 10⁴ (hydraulic diameter 0.05 m, first inlet).
Every number on this page comes from this run's own files (summary.json, the solver's histories); none is typed in by hand or written by AI. The raw data is in the data folder. Print this page (A4) for a hand-out. Run folder: C:\Users\niels\Dropbox\Brain Vault\Brain\Projects\Laminaro\jobs\Hot and cold water mixing in a tee · Example · Hot and cold water mixing in a tee · run 2 2026-10-29 1141\results