Laminaro CFD

Examples

Five solved studies you can open in Inventor

Each example ships solved, with a guided tour through the real windows. Open it from Explore LaminaroCFD › Examples inside the add-in, or download it here.

Wind on a silo

The wind load on a free-standing silo on open ground, the case EN 1991-1-4 §7.9 covers with a force coefficient. Laminaro builds the air around the part and the log-law wind over the terrain.

Set-up

Part
Ø3 × 6 m silo standing on the ground
Wind
EN 1991-1-4 log-law profile, terrain category II (z0 = 0.05 m); 22.74 m/s at the reference height
Fluid
Air at 20 °C
Out
Drag, lift, Cd, pressure on the walls, the wake, report and video

Result

Drag2 044 N ± 0.1 %
Cd0.365 ± 0.1 %
Lift1 274 N
Checked against: the reference case silo on open ground: cf 0.354 against 0.350 from EN 1991-1-4 §7.9, +1.1 %. The code's cf uses the wind pressure at the top of the silo; the mean force in a log-law wind is about 0.70 of that, so the fair reference is cf0·ψλ·0.70. Laminaro's Cd is the real mean force, which is why it sits below a code cf taken at face value.
Download the solved example (.zip)
The silo example in Laminaro's post-processing window: drag 2 044 N, Cd 0.365, lift 1 274 N, and the pressure on a section cut.
6 Post-processing › Check: the result, its ±, the verdict and the AI review.
Pressure on a section cut through the silo: high on the windward side, suction in the wake.
Explore: pressure relative to the outlet on a cut through the silo.

Pipe with a sudden expansion

Air through a pipe that steps from Ø50 to Ø100 mm. The textbook case for a loss coefficient, with four measurements along the pipe.

Set-up

Part
Ø50 → Ø100 mm, 1.2 m of pipe
Flow
Air at 20 °C, 10 m/s at the inlet
Model
k-ω SST, chosen from Re 3.3·10⁴
Measured
Inlet, outlet, before and after the step

Result

Pressure drop45.64 Pa ± <0.1 %
K0.758
Flow19.51 l/s
Checked against: Borda–Carnot. The loss at the step alone is K = (1 − (d/D)²)² = 0.5625; the reference case for this step gives 0.5594, −0.5 %. The example's K of 0.758 is from inlet to outlet, so it holds the pipe friction as well as the step.
Download the solved example (.zip)
The pipe-expansion example in Laminaro: pressure drop 45.64 Pa, loss coefficient 0.7582, streamlines coloured by velocity, and the four measurements.
Check: the pressure drop, K, the flow rate, and the measurements before and after the step.

Water through a pipe bend

A 90° bend in a Ø50 mm water pipe. For a liquid with one inlet and one outlet, Laminaro leads with the numbers a valve or fitting datasheet gives: the flow coefficients Kv and Cv.

Set-up

Part
Ø50 mm pipe, 90° bend with R 75 mm (R/D 1.5), 5 D before and 10 D after the bend
Flow
Water at 20 °C, 2 m/s (14.1 m³/h)
Mesh
Standard, 515 k cells, converged at 315 iterations

Result

Pressure drop872 Pa
Kv151 m³/h
Cv174
K0.437
Checked against: the hand estimate of Kv, about 150 for this pipe. The K of 0.437 is for the whole pipe: about 0.30 is straight-pipe friction and about 0.14 the bend. The bend's own loss is in the reference suite: K 0.168–0.176 on three meshes against 0.17–0.21 in Idelchik's diagram 6-1 (see Verification).
Download the solved example (.zip)
Velocity on a section through the pipe bend: the flow speeds up on the inside of the bend and separates just after it.
Velocity on a cut through the bend: the fast inner side and the slow zone just after it.
Streamlines through the pipe bend, coloured by velocity, inside the semi-transparent pipe wall.
Streamlines from the inlet, coloured by velocity.

Hot and cold water mixing in a tee

Cold water along a Ø50 mm main pipe meets hot water from a Ø32 mm branch. Each inlet brings its own temperature; Laminaro carries it with the flow and tells you how well the two streams have mixed by the outlet: the length a sensor or a thermostat needs downstream.

Set-up

Part
Ø50 mm main pipe (0.9 m), Ø32 mm branch from above, 0.3 m from the cold inlet
Flow
Cold water 15 °C at 1 m/s, hot water 60 °C at 1.5 m/s
Model
Temperature carried with the flow (mixing; the walls pass no heat)
Mesh
Standard, 531 k cells

Result

Outlet32.1 °C
Pressure drop1 160 Pa
Flow3.15 l/s
Checked against: the heat balance of the two streams: the flow-weighted mean of 15 °C and 60 °C over the two inlets' flows is the mixed temperature the outlet must reach, and the run's outlet sits on it.
Download the solved example (.zip)
Streamlines through the mixing tee, coloured by temperature: the hot jet from the branch bends over with the cold stream and rides on top of it as a warm layer.
Streamlines coloured by temperature: blue 15 °C, red 60 °C. The hot jet rides on the cold stream before it mixes.

Diameter study

Which diameter gives the lowest pressure drop? The pipe's diameter D is an Inventor parameter; Laminaro runs one case per value and marks the best.

Set-up

Part
A 1 m pipe whose diameter D is a named Inventor parameter
Values
D = 60, 80 and 100 mm
Flow
Air at 20 °C, 5 m/s at the inlet
Mesh
Standard, about 493 k cells per case

Result

D 60 mm7.798 Pa
D 80 mm5.69 Pa
D 100 mm ✓4.479 Pa
Checked against: the pipe-friction reference cases (Colebrook): −2.0 % at Re 10⁶ and −8.2 % at Re 10⁵. This study runs at lower Reynolds numbers still, so its ranking is more certain than its absolute pressure drops. The AI review says so too: the best case sits at the end of the range, so it is the best value tried, not an optimum.
Download the solved example (.zip)
The diameter study in Laminaro: a table of the three diameters with their pressure drops, D 100 mm marked best, and the AI review warning that the best case sits at the range's end.
Check: the three cases, the best one marked, and the AI review's note on the range.