CFD Case Study: How Louvre Blade Design Reduces Wind Noise and Improves Airflow

Shahram Derakhshan
Oct 6
2 min read

CFD airflow simulation comparing flat and curved louvre blades by Deratec.

Project Overview

At Deratec, we help designers and manufacturers create smarter façades and ventilation systems through advanced Computational Fluid Dynamics (CFD) and acoustic simulation.

In this case study, we compared two ALSPEC louvre profiles — one flat (LV80) and one curved (LVE80) — to understand how blade geometry affects airflow and wind-induced noise at a typical façade face velocity of 5 m/s.

CFD model showing the LV80 flat louvre arrangement and LVE80 curved elliptical louvre arrangement used for airflow and noise generation simulation at 5 m/s face velocity. — CFD geometry comparison of the flat LV80 and curved LVE80 louvre blade configurations used in the aerodynamic and acoustic analysis.

Project Snapshot

Parameter	Setting
Profiles	LV80 (flat) – Pages 30–31 · LVE80 (curved/elliptical) – Pages 52–53
Blade angle	45°
Pitch	65 mm
Face velocity	5 m/s
Model	2D section with 3 blades
Analysis	Airflow + 1/3-octave acoustic spectrum (250–5 000 Hz)

Engineering drawings showing the ALSPEC LV80 flat blade and LVE80 curved elliptical louvre blade geometries, both with a 45° blade angle, used in the CFD and acoustic study.

Comparison of ALSPEC LV80 (flat) and LVE80 (curved) louvre blade profiles used in the CFD analysis.

CFD Insights

CFD visualisation revealed that the curved LVE80 profile produced smoother airflow and fewer large vortices, while the flat LV80 blade generated stronger separation and fluctuating pressure zones. These flow instabilities are the main source of vortex-induced noise and higher acoustic energy.

By streamlining the flow path, the curved LVE80 redistributed acoustic energy — lowering the low-frequency “rumble” and shifting some sound to higher, less perceptible frequencies. The result is a quieter and more uniform acoustic signature, characteristic of efficient aerodynamic design.

CFD visualisation showing wake structure and turbulence intensity for curved versus flat louvre designs. — The LVE80’s curved geometry reduces separation and vortex formation compared with the flat LV80.

Noise Spectrum Comparison

A detailed 1/3-octave band analysis was conducted for the 250–5000 Hz range — the most sensitive range of human hearing and the dominant band for façade noise perception.

Sound pressure level comparison between flat and curved louvres. — LVE80 achieved up to 10 dB reduction across 250–5,000 Hz — the range most audible to humans.

Metric	LV-80	LVE-80	Difference
OASPL (250–5,000 Hz)	93.7 dB	83.8 dB	−9.9 dB

The curved LVE-80 blade achieved nearly 10 dB lower overall noise, equivalent to a ten-fold reduction in acoustic energy or roughly half the perceived loudness.

Practical Takeaways

Curved blades can lower perceived noise while maintaining airflow efficiency.
CFD + acoustic analysis enables data-driven optimisation before fabrication.
Designers gain confidence that louvres meet both comfort and compliance goals.
Noise generation can be tuned through geometry, pitch, and edge profile design.

Conclusion

This CFD case study illustrates how minor design adjustments can yield significant performance improvements. At a modest 5 m/s airflow, the LVE-80 curved louvre reduced total aerodynamic noise by around 10 dB compared with the flat LV-80 design — a clear validation of aerodynamic optimisation for façade systems.

By integrating CFD and acoustic simulation, Deratec helps clients design façades that are smarter, quieter, and more efficient — balancing airflow, comfort, and compliance with confidence.