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Laminar Flow

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Related Experiment Video

Updated: Apr 25, 2026

Preparation of Free-Surface Hyperbolic Water Vortices

Preparation of Free-Surface Hyperbolic Water Vortices

Published on: July 28, 2023

Vortex ventilation in the laboratory environment.

Lawrence R Meisenzahl¹

¹a Engineering Department , E.I. DuPont de Nemours and Company , Wilmington , Delaware.

Journal of Occupational and Environmental Hygiene

|September 2, 2014

Summary

A novel vortex-enhancing design significantly improves containment in chemical fume hoods at low airflow, offering better user protection and reduced operating costs. This innovation addresses long-standing challenges in ventilated enclosure performance.

Keywords:

chemical hood ventilated enclosure

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Published on: August 7, 2014

Area of Science:

Occupational Health and Safety
Mechanical Engineering
Environmental Science

Background:

Ventilated enclosures, such as chemical fume hoods, often struggle to maintain assured containment at low airflow rates.
This limitation poses risks to users and can increase operational expenses due to higher ventilation requirements.

Purpose of the Study:

To investigate if a specific interior hood shape that promotes a natural vortex can enhance contaminant containment.
To compare the containment performance of a traditional chemical fume hood with a modified design featuring an enhanced vortex.

Main Methods:

The study employed the ASHRAE 110 tracer gas test to evaluate containment effectiveness.
Tracer gas concentrations escaping a traditional hood and a vortex-enhanced hood were measured using an infrared spectrometer.
Experimental design included a defined operating procedure, data collection plan, and statistical analysis.

Main Results:

The vortex-enhancing hood design demonstrated significant improvements in containment compared to the traditional design across all tested parameters.
Analysis using the Hood Index indicated a direct relationship between containment and airflow, supporting the vortex hypothesis.
The sustained vortex effectively improved the containment of contaminants within the enclosure, even at low airflow.

Conclusions:

A vortex-enhancing interior shape can substantially improve the containment capabilities of ventilated enclosures like chemical fume hoods.
This design offers enhanced user protection and potential for lower operating costs by enabling effective containment at reduced airflow.
The findings suggest a promising approach for optimizing the performance of industrial and laboratory ventilation systems.