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

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?

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

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

 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

  Case 1 2 3 4

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

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

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

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

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

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