1. Mahnameh TAHERI, Ardeshir MAHDAVI
An efficient approach to the parametric assessment of airflow conditions in architectural spaces based on a limited set of CFD-based simulation runs
Mahnameh TAHERI, Ardeshir MAHDAVI
Department of Building Physics & Building Ecology
TU Wien, Austria
CESB 2016

2. Question:
Can we obtain basic air flow field information
for a LARGE variety of design configurations
based on a SMALL number of full-fledge CFD simulation runs?

3. CFD modelling scenarios
a shoebox model
simple rectangular zone, without openings
Commercially available CFD tool (DesignBuilder)
multiple design variables pertaining to diffuser configurations and airflow rates

4. 3 different ceiling inlet/outlet configurations Various airflow rates
First scenario:
3 different ceiling inlet/outlet configurations Various airflow rates
Question:
Can we simulate in detail one air flow field velocity to predict others?
Layout A
Layout B
Layout C

5.  Strong linear relationship
First scenario:
Simulation result
f2 = 2 f1
30/60
45/90
f2 = 3 f1
30/90
45/135
 Strong linear relationship
More than 350 grid nodes at the height of 1.1 m from the floor level

6. Case 1 2 3 4

7. Cumulative distributions of relative errors and percentage of results within different bins of absolute error

8. Air flow field simulated for layouts A, B and C Various airflow rates
Second scenario:
Air flow field simulated for layouts A, B and C
Various airflow rates
Question:
Can we predict the air flow field in layout C based on detailed CFD simulations for A and B?
Layout A
Layout B
Layout C

9. Mathematical superimposition of the results of A and B:
Averaging the values at each grid node
Test:
Comparison of simple calculations of the air flow field velocity in layout C with detailed CFD simulations
Case
Air flow rate (l.s-1)
A, B C 1 30 60 2 45 90 3
120

10. Cumulative distributions of relative errors and percentage of results within different bins of absolute error

11. Conclusions
Encouraging congruence between simple calculation results and those of full CFD
Potential to reduce the extent of computational resources for routine architectural ventilation tasks
Next step:
further evaluation of the proposed approach
involving a broader set of instances and options
with regard to factors such as space geometry, diffuser configurations, and boundary conditions

12. Mahnameh TAHERI, Ardeshir MAHDAVI
An efficient approach to the parametric assessment of airflow conditions in architectural spaces based on a limited set of CFD-based simulation runs
Mahnameh TAHERI, Ardeshir MAHDAVI
Department of Building Physics & Building Ecology
TU Wien, Austria
CESB 2016