### Abstract

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

Title of host publication | 33rd AIVC and 2nd TightVent Conference : Optimising ventilative cooling and airtightness for (nearly) zero-energy buildings, IAQ and comfort: Proceedings |

Number of pages | 4 |

Place of Publication | Copenhagen |

Publisher | AIVC |

Publication date | 2012 |

Pages | 270-273 |

Publication status | Published - 2012 |

Event | 33rd AIVC and 2nd TightVent Conference: Optimising ventilative cooling and airtightness for (nearly) zero-energy buildings, IAQ and comfort - Axelborg, København, Denmark Duration: 10 Oct 2012 → 11 Oct 2012 |

### Conference

Conference | 33rd AIVC and 2nd TightVent Conference |
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Location | Axelborg |

Country | Denmark |

City | København |

Period | 10/10/2012 → 11/10/2012 |

### Fingerprint

### Bibliographical note

Proceedings is handed out at the conference in print### Keywords

- Centre pivot roof window
- Discharge Coefficient
- CFD

### Cite this

*33rd AIVC and 2nd TightVent Conference: Optimising ventilative cooling and airtightness for (nearly) zero-energy buildings, IAQ and comfort: Proceedings*(pp. 270-273). Copenhagen: AIVC.

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*33rd AIVC and 2nd TightVent Conference: Optimising ventilative cooling and airtightness for (nearly) zero-energy buildings, IAQ and comfort: Proceedings.*AIVC, Copenhagen, pp. 270-273, København, Denmark, 10/10/2012.

**The Discharge Coefficient of a Centre-Pivot Roof Window.** / Iqbal, Ahsan; Afshari, Alireza; Nielsen, Peter V.; Heiselberg, Per.

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

TY - GEN

T1 - The Discharge Coefficient of a Centre-Pivot Roof Window

AU - Iqbal, Ahsan

AU - Afshari, Alireza

AU - Nielsen, Peter V.

AU - Heiselberg, Per

N1 - Proceedings is handed out at the conference in print

PY - 2012

Y1 - 2012

N2 - Accuracy in estimation of airflow through windows is the key parameter for modelling and designing of naturally ventilated buildings. The flow through windows is usually described by the orifice flow plate equation. This equation involves the discharge coefficient. In practice, often a constant value of discharge coefficient is used. The constant value of discharge coefficient leads to deceptive airflow estimation in the cases of centre-pivot roof windows. The object of this paper is to study and evaluate the discharge coefficient of the centre pivot roof window. Focus is given on unidirectional flows i.e. inflow and outflow. CFD techniques are used to predict the airflow through the modelled window. Analytical orifice flow equation is used to calculate the discharge coefficient. Results are compared with experimental results. It is concluded that the single value of the discharge coefficient leads to ambiguous estimation of airflow rates. The discharge coefficient decreases with increase in flap opening area. The discharge coefficient also depends upon the flow direction.

AB - Accuracy in estimation of airflow through windows is the key parameter for modelling and designing of naturally ventilated buildings. The flow through windows is usually described by the orifice flow plate equation. This equation involves the discharge coefficient. In practice, often a constant value of discharge coefficient is used. The constant value of discharge coefficient leads to deceptive airflow estimation in the cases of centre-pivot roof windows. The object of this paper is to study and evaluate the discharge coefficient of the centre pivot roof window. Focus is given on unidirectional flows i.e. inflow and outflow. CFD techniques are used to predict the airflow through the modelled window. Analytical orifice flow equation is used to calculate the discharge coefficient. Results are compared with experimental results. It is concluded that the single value of the discharge coefficient leads to ambiguous estimation of airflow rates. The discharge coefficient decreases with increase in flap opening area. The discharge coefficient also depends upon the flow direction.

KW - Centre pivot roof window

KW - Discharge Coefficient

KW - CFD

KW - Centre pivot roof window

KW - Discharge Coefficient

KW - CFD

M3 - Article in proceeding

SP - 270

EP - 273

BT - 33rd AIVC and 2nd TightVent Conference

PB - AIVC

CY - Copenhagen

ER -