Bernoulli-induced self-cleaning in drainage pipes: visual micro-Venturi validation

Area of Science:

• Fluid dynamics
• Environmental engineering
• Material science

Background:

• Conventional sediment removal from drainage systems is energy-intensive.
• Passive self-cleaning mechanisms offer a sustainable alternative.
• The Bernoulli principle can be leveraged for fluidic cleaning applications.

Purpose of the Study:

• To evaluate a passive self-cleaning mechanism for drainage systems.
• To quantify the relationship between wall shear stress and sediment removal rate.
• To develop a dimensionless factor for scaling the technology.

Main Methods:

• A laboratory-scale micro-Venturi was used to simulate sediment removal.
• Hydraulically induced wall shear stress (τ) was measured.
• The removal rate (R) of a kaolinite surrogate deposit was quantified.

Main Results:

• A strong linear correlation (r = 0.958) was found between wall shear stress (τ) and sediment removal rate (R).
• A critical shear stress (τ_c ≈ 5.8 Pa) was identified for effective deposit removal (>60%).
• Flow rates between 1-12 L·min⁻¹ generated wall shear stresses up to 102.1 Pa.

Conclusions:

• The passive self-cleaning mechanism effectively removes sediment using minimal energy.
• A dimensionless scaling factor (Π = τ/τ_c) was developed for designing larger-scale applications.
• This technology offers a promising energy-efficient solution for maintaining drainage systems.