# Computational Analysis of Natural Ventilation Flows in Geodesic Dome Building in Hot Climates

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## Abstract

**:**

## 1. Introduction

## 2. Literature Review

## 3. Computational Modelling

#### 3.1. Model Geometry

#### 3.2. Computational Mesh Design

#### 3.3. Sensitivity Analysis

#### 3.4. Convergence of Solution and Conservation of Property

^{−6}and 10

^{−3}as the default convergence criterion for the energy equation and all other equations respectively. However, this pre-defined convergence criterion does not apply to all types of simulations and in this study this option was not used and instead the residuals were monitored as shown in Figure 6a. The iteration process is continued until there was no difference between the iterations. In addition, quantities such as the air velocity near the roof (9 m height) and middle (3 m height) (Figure 6b,c) were also monitored. Furthermore, the conservation of properties (mass flux balance) was also achieved. The mass flux balance was below the required value or below 1% of smallest flux through the computational domain.

#### 3.5. Method Validation

_{ref}= −0.163. It can be seen in Figure 7 that the current model’s results have a good agreement with the numerical and experimental data, although the results of the current model were more consistent with the numerical data particularly beyond y/H

_{ref}= 0.2. In all cases, the u component is lower closer to the ground and increases gradually upwards while the v component decreases gradually with elevation. Figure 8 displays a comparison between the numerical results and experimental data for streamwise and cross-streamwise velocity flow profiles at z/H

_{ref}= −0.155. Similarly, the streamwise velocity flow profile was in good agreement with previous works´ numerical and experimental results, however, the cross-streamwise velocity flow profile was more consistent with the experimental data for this location. Overall, the numerical code was capable of accurately simulating the wind-flow conditions around a domed-roof building and was therefore employed in this study.

#### 3.6. Boundary Conditions

^{2}. This was set based on typical internal heat gain levels in residential buildings. This takes into account heat gains from lighting (10 W/m

^{2}), equipment (12 W/m

^{2}) and occupancy (3 W/m

^{2}) [39,40]. These values vary greatly based on many factors such as the design, use of space, indoor and outdoor conditions, etc.; however, for the purpose of this study, this was set to a constant value for simplification and should be sufficient for investigating the capabilities of the ventilation strategy to cool the indoor space. The boundary conditions for the CFD model are shown in Table 2.

#### 3.7. Case Study Location

#### 3.8. Measurement of Indoor Velocity and Temperature

## 4. Results and Discussion

#### 4.1. Wind-Induced Flows

#### 4.1.1. Velocity Distribution (Wind-Induced Flows)

#### 4.1.2. Temperature Distribution (Wind-Induced Flows)

#### 4.2. Buoyancy-Induced Flows

#### 4.2.1. Velocity Distribution (Buoyancy-Induced Flows)

#### 4.2.2. Temperature Distribution (Buoyancy-Induced Flows)

## 5. Conclusions

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## Abbreviations

ABL | Atmospheric Boundary Layer |

CFD | Computational Fluid Dynamics |

FVM | Finite Volume Method |

HVAC | Heating, Ventilation and Air-Conditioning |

RANS | Reynolds-Averaged Navier-Stokes |

SIMPLE | Semi-Implicit Method for Pressure-Linked Equations |

TKE | Turbulence Kinetic Energy |

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**Figure 3.**Different types of icosahedron-based geodesic domes [36]. Reproduced with permission from Rene K. Mueller, SimplyDifferently.org; published by 2014.

**Figure 6.**(

**a**) FLUENT solution residuals and monitoring of convergence for (

**b**) velocity at 9 m; and (

**c**) velocity at 3 m.

**Figure 7.**Comparison between numerical predictions and numerical/experimental data [37] for streamwise and cross-stream velocity results at z/H

_{ref}= −0.163.

**Figure 8.**Comparison between numerical predictions and numerical/experimental data [37] for streamwise and cross-stream velocity results at z/H

_{ref}= −0.155.

**Figure 10.**(

**a**) Streamline plot of velocity inside the dome during summer with wind-induced flow; (

**b**) Velocity contour results of the airflow distribution inside the dome (wind-induced flows).

**Figure 11.**Comparison of the airflow velocity distribution inside the dome house during winter and summer (wind-induced flows).

**Figure 12.**Mid-plane contour plot of the temperature distribution inside the dome during summer month of July (wind-induced flows).

**Figure 13.**Comparison of the airflow velocity distribution inside the dome house during winter month of January (wind-induced flows).

**Figure 14.**Comparison of the airflow temperature distribution inside the dome house during winter and summer (wind-induced flows).

**Figure 15.**Streamline plot of velocity inside the dome during winter with very low or no wind speed.

**Figure 16.**Comparison of the airflow speed distribution inside the dome house during winter and summer (buoyancy-induced flows).

**Figure 17.**Comparison of the airflow speed distribution inside the dome house during winter and summer (buoyancy-induced flows).

**Figure 18.**Mid-plane contour plot of the temperature distribution inside the dome with during summer and winter (buoyancy-induced flows).

**Figure 19.**Comparison of the airflow temperature distribution inside the dome house during winter and summer (buoyancy driven flows).

Specification | Dimensions |
---|---|

Base Diameter at A | 13.70 m |

Height at C | 2.41 m |

Height at B | 9.06 m |

Height of Riser D | 0.33 m |

Entrance Opening E | 5.46 m |

Floor area at base | 143 m^{2} |

Roof area | 329 m^{2} |

Volume | 864 m^{3} |

Parameter | Dimensions |
---|---|

Geometry | Solid zone |

Enclosure | Fluid zone |

Turbulence Model | Standard k-epsilon |

Near-Wall Treatment | Standard Wall Functions |

Velocity Formulation | Absolute |

Velocity Inlet | ABL Profile (see Section 3.6) |

Pressure Outlet | Atmospheric |

Temperature Inlet | see Temperature in Section 3.6 |

Solver Type | Pressure-Based |

Time | Steady |

Gravity | −9.81 m/s^{2} |

Points | X [m] | Y [m] | Z [m] | ||

Lower Floor | 1 | −3.6 | 3.6 | 1.2 | |

2 | 0 | 3.6 | 1.2 | ||

3 | 3.6 | 3.6 | 1.2 | ||

4 | −3.6 | 0 | 1.2 | ||

5 | 0 | 0 | 1.2 | ||

6 | 3.6 | 0 | 1.2 | ||

7 | −3.6 | −3.6 | 1.2 | ||

8 | 0 | −3.6 | 1.2 | ||

9 | 3.6 | −3.6 | 1.2 | ||

Upper Floor | 11 | −3.6 | 3.6 | 4.2 | |

12 | 0 | 3.6 | 4.2 | ||

13 | 3.6 | 3.6 | 4.2 | ||

14 | −3.6 | 0 | 4.2 | ||

15 | 0 | 0 | 4.2 | ||

16 | 3.6 | 0 | 4.2 | ||

17 | −3.6 | −3.6 | 4.2 | ||

18 | 0 | −3.6 | 4.2 | ||

19 | 3.6 | −3.6 | 4.2 |

© 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).

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**MDPI and ACS Style**

Soleimani, Z.; Calautit, J.K.; Hughes, B.R.
Computational Analysis of Natural Ventilation Flows in Geodesic Dome Building in Hot Climates. *Computation* **2016**, *4*, 31.
https://doi.org/10.3390/computation4030031

**AMA Style**

Soleimani Z, Calautit JK, Hughes BR.
Computational Analysis of Natural Ventilation Flows in Geodesic Dome Building in Hot Climates. *Computation*. 2016; 4(3):31.
https://doi.org/10.3390/computation4030031

**Chicago/Turabian Style**

Soleimani, Zohreh, John Kaiser Calautit, and Ben Richard Hughes.
2016. "Computational Analysis of Natural Ventilation Flows in Geodesic Dome Building in Hot Climates" *Computation* 4, no. 3: 31.
https://doi.org/10.3390/computation4030031