### Abstract

*L/D*ranging from 0.027 to 4.455, where

*L*and

*D*are the length of the opening and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant injection tracer gas technique. Smoke visualizations showed that the airflow patterns are highly transient and unstable, and that the airflow rate oscillates with time. Correlations between the Froude (Archimedes) number

*Fr (Ar)*and the

*L/D ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula*ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula but in other cases the measured data show clear deviations from the Epstein's formula. Thus, revised formulas for natural ventilation are proposed.

Original language | English |
---|---|

Title of host publication | The Third International Workshop on Natural Ventilation : Proceedings, March 16, 2009, Tokyo |

Number of pages | 8 |

Publisher | Tokyo University of Science |

Publication date | 2009 |

Publication status | Published - 2009 |

Event | The International Workshop on Natural Ventilation - Tokyo, Japan Duration: 16 Mar 2009 → 16 Mar 2009 Conference number: 3 |

### Conference

Conference | The International Workshop on Natural Ventilation |
---|---|

Number | 3 |

Country | Japan |

City | Tokyo |

Period | 16/03/2009 → 16/03/2009 |

### Fingerprint

### Bibliographical note

Published in a printed proceedings.### Keywords

- Natural ventilation
- Air flow rate
- Buoyancy
- Horizontal opening
- Tracer gas
- LES

### Cite this

*The Third International Workshop on Natural Ventilation: Proceedings, March 16, 2009, Tokyo*Tokyo University of Science.

}

*The Third International Workshop on Natural Ventilation: Proceedings, March 16, 2009, Tokyo.*Tokyo University of Science, Tokyo, Japan, 16/03/2009.

**Buoyancy Driven Natural Ventilation through Horizontal Openings.** / Heiselberg, Per.

Research output: Contribution to book/anthology/report/conference proceeding › Article in proceeding › Research › peer-review

TY - GEN

T1 - Buoyancy Driven Natural Ventilation through Horizontal Openings

AU - Heiselberg, Per

N1 - Published in a printed proceedings.

PY - 2009

Y1 - 2009

N2 - An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant injection tracer gas technique. Smoke visualizations showed that the airflow patterns are highly transient and unstable, and that the airflow rate oscillates with time. Correlations between the Froude (Archimedes) number Fr (Ar) and the L/D ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula but in other cases the measured data show clear deviations from the Epstein's formula. Thus, revised formulas for natural ventilation are proposed.

AB - An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant injection tracer gas technique. Smoke visualizations showed that the airflow patterns are highly transient and unstable, and that the airflow rate oscillates with time. Correlations between the Froude (Archimedes) number Fr (Ar) and the L/D ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula but in other cases the measured data show clear deviations from the Epstein's formula. Thus, revised formulas for natural ventilation are proposed.

KW - Natural ventilation

KW - Air flow rate

KW - Buoyancy

KW - Horizontal opening

KW - Tracer gas

KW - LES

M3 - Article in proceeding

BT - The Third International Workshop on Natural Ventilation

PB - Tokyo University of Science

ER -