The twodimensional benchmark test, also called the “IEA 2D test case”, was defined in 1990 to be used in the IEA Annex 20 work, but a significant number of papers have used this geometry in other CFD work.
We believe that it is attractive to a new user to stick to a geometry used by a number of other researchers. It is possible to compare the results with other authors’ results (other turbulence models, other numerical schemes, etc.). The basic knowledge behind the benchmark test has thus expanded during the years and made the test case more useful.
The benchmark test
Selected literature
19731981
 Brechnung der Luftbewegung in einem zwangsbelüfteten Raum (Peter V. Nielsen, 1973)
 Prediction of Temperature and Velocity distribution in an air conditioned room (Peter V. Nielsen, 1974)
 Moisture Transfer in Air Conditioned Rooms and Cold Stores (Peter V. Nielsen, 1974A)
 Die Berechnung von Raumströmungen (Peter V. Nielsen, 1975)
 Contaminant distribution in industrial areas with forced ventilation and twodimensional flow (Peter V. Nielsen, 1981)
19921994
 Numerical prediction of flows confined by irregular boundaries, of relevance to room ventilation (F. A. Castro and A. Restivo, 1992)
 Chen, Q. and Z. Jiang, Significant Questions in Predicting Room Air Motion, ASHRAE Transactions, Part 1, 1992, pp. 929932.
 Influence of turbulence parameters at supply inlet on room air diffusion (M.N.A. Said, D.B. Jouini, E.G. Plett, 1993)
 A Full Multigrid Method Applied to Turbulent Flow using the SIMPLEC Algorithm Together with a Collocated Arrangement (P.Johansson and L. Davidson, 1994)
 Room Air and Contaminent Flow, Evaluation of Computational Methods (A. D. Lemaire, Q. Chen, M. Ewert, J. Heikkinen, C. Inard, A. Moser, P. V. Nielsen and G. Whittle, 1993)
 Prospects for computational fluid dynamics in room air contaminant control (Peter V. Nielsen, 1994)
 Numerical computation of flow and heat transfer in airconditioned rooms by a special velocitypressure iteration and multigrid method (M. Rösler and B. Hanel, 1992)
 Said, M.N.A., D.B. Jouini and E.G. Plett, Influence of Turbulence Parameters at Supply Inlet on Room Air Distribution, ASME Winter Annual Meeting, New Orleans, 1993.
 Comparative studies of selected discretization methods for the numerical solution of room air flow problems (T. Skalický, G. Morgenstern, A. Auge, B. Hanel and M. Rösler, 1992)
 Numerical prediction of buoyant air flow in livestock buildings (K. Svidt, 1993)
19951998
 CFDsimulation of personal exposure to contaminant sources in ventilated rooms (H. Brohus, 1997A)
 Chen, Q., Comparison of Different kε Models for Indoor Air Flow Computations, Numerical Heat Transfer, Part B, 28: 353369, 1995.
 Chen, Q., Prediction of Room Air Motions by ReynoldsStress Models, Building and Environment, Vol. 3.1, No 3, pp. 233244, 1996.
 Simplified Method for Indoor Airflow Simulation (Qingyan Chen and Weiran Xu, 1997)
 Large Eddy simulations of the flow in a threedimensional ventilated room (L. Davidson and P. V. Nielsen, 1996)
 Part 1, Implementation of a large Eddy simulation method applied to recirculating flow in a ventilated room (L. Davidson, 1996)
 Part 2, Implementation of a large Eddy simulation method applied to recirculating flow in a ventilated room (L. Davidson, 1996)
 Numerical study of the influence of inlet boundary conditions on the air movement in a ventilated enclosure (P. Joubert, A. Sandu, C. Béghein and F. Allard, 1996)
 P.V. Nielsen, The Selection of Turbulence Models for Prediction of Room Airflow. ASHRAE Transactions. – 1998; Vol. 104, Part 1B. – pp. 1119 1127. – ISSN: 00012505.
 Performance of twoequation turbulence models for numerical simulation of ventilation flows (S. Peng, L. Davidson and S. Holmberg, 1996)
 A modified lowReynoldsnumber kw model for recirculating flows (S. Peng, L. Davidson and S. Holmberg, 1997)
 The twoequation turbulence kw model applied to circulating ventilation flows (S. Peng, L. Davidson and S. Holmberg, 1996)
 Evaporation controlled emission in ventilated room (C. Topp, P.V. Nielsen and P. Heiselberg, 1997)
20002004
 Collignan, B. and J. Ribéron, A Numerical Study on Pollutant Removal Effectiveness of a Room, Air Distribution in Rooms, (ROOMVENT 2000), Elsevier 2000.
 Zonal model based on airflow partitioning (S. Guernouti, M. Musy, L. Mora and G. Hégron, 2004)
 Mora, L., A. J. Gadgil and E. Wurtz, Comparing Zonal and CFD Model Predictions of Isothermal Indoor Airflows to Experimental Data, Indoor Air 2003; 13; 7785.
 Peng, S.H. and L. Davidson, The Potential of Large Eddy Simulation Techniques for Modelling Indoor Air Flows, Air Distribution in Rooms, (ROOMVENT 2000), Elsevier 2000.
 MODELING CHEMICAL REACTIONS IN THE INDOOR ENVIRONMENT BY CFD (D. N. Sørensen, C. J. Weschler, 2002)
 Sørensen, D.N. and C.J. Weschler, ModelGas Phase Reactions in Indoor Environments Using Computational Fluid Dynamics, Atmospheric Environment 36 (2002) 918.
 Teshome, E. J. and F. Haghighat, Zonal Models for Indoor Air Flow – A Critical Review, The International Journal of Ventilation, Vol. 3, No. 2, pp. 119129, 2004.
 C. Topp, P. V. Nielsen and P. Heiselberg, Influence of Local Airflow on the Pollutant Emission from Indoor Building Surfaces. Indoor Air 2001; pp. 162170.
 Comparison of Turbulence Models for Numerical Calculation of Airflow in an annex 20 Room (L. Voight, 2000)
 Numerical analysis of particle dispersion in indoor air using Lagrangian method (Z. Zhang and Q. Chen, 2004)
 CFD for simulating air distribution in buildings: the state of the art, challenges, and opportunities (Q. Chen, 2009)
 Comparison of different subgrid turbulence models and boundary conditions for largeEddysimulations of room air flows (D. Müller andL. Davidson, 2000)
 Macroscopic and microscopic analysis of zonal models ( E. J. Teshome and F. Haghighat, 2005)
 Applications of highresolution schemes based on normalized variable formulation for 3D indoor airflow simulations (K. C. Ng, E. Y. K. Ng, M. Z. Yusoff and T. K. Lim, 2008)
 Validation of the zonal method for the case of isothermal airflow in a rectangular cavity (T. Czelusniak, K. C. Mendonça, and M. O. Abadie, 2009)
 The IEA Annex 20 TwoDimensional Benchmark Test for CFD Predictions (Peter V. Nielsen, Li Rong and Inés Olmedo, 2010)
 Analysis of the IEA 2D test. 2D, 3D, steady or unsteady airflow? (Inés Olmedo and Peter V. Nielsen, 2010)
 Simulation with different turbulence models in an annex 20 room benchmark test using Ansys CFX 11.0 (L. Rong and P. V. Nielsen, 2008)
 Realtime or fasterthanrealtime simulation of airflow in buildings (W. Zou and Q. Chen, 2008)
2011 2020
 Simulation with different turbulence models in an Annex 20 benchmark test using StarCCM+ (Jérôme Le Dréau, Per Heiselberg, Peter V. Nielsen, 2012)
 A Discussion of Low Reynolds Number Flow for the TwoDimensional Benchmark Test Case (M. Weng, P. V. Nielsen and L. Liu, 2012)

CFD Benchmark Tests for Indoor Environmental Problems: Part 1 Isothermal/NonIsothermal Flow in 2D and 3D Room Model (K. Ito, K. Inthavong, etc., 2015)
 Evaluation of mean velocity and mean speed for test ventilated room from RANS and LES CFD modeling (N. Ivanov, et al., 2018)
2021 PRESENT
 Returning characteristics of pollutants for a local domain in the presence of returning and recirculating airflow in indoor environments (Eunsu Lim, Mats Sandberg, Kazuhide Ito, 2021)
IEA ANNEX 20
 Simulation of simple test cases (Q. Chen, 1991)
 Simulation of simple (twodimensional) test cases (J. Heikkinen and K. Piira, 1991)
 Simulation of simple test cases 2d1, 2d2 (A. D. Lemaire, 1991)
 Simulation of a twodimensional benchmark test case (M. N. Said, 1991)
 Simulation of simple test case, case 2d1 (M. Skovgaard and P. V. Nielsen, 1991)
 Simulation of simple test cases (N. Vogel and U. Renz, 1991)
PHD THESES
 Numerical Simulation of Turbulent Airflow in Livestock Buildings  abstract (J. C. Bennetsen, 1999)
 Numerical Simulation of Turbulent Airflow in Livestock Buildings (H. Brohus, 1997)
 Development and Implementation of Fast Implicit Multigrid Method for Large Eddy Simulations (P. Emvin and L. Davidson, 1997)
 Flow in air conditioned rooms  model experiments and numerical solution of the flow equations (P. V. Nielsen, 1974)
 Zhengen Ren, Enhanced modelling of indoor air flows, temperatures, pollutant, emission and dispersion by nesting subzones within a multizone model. PhD Thesis, The Queens University of Belfast, September 2002
 Diffusion and evaporationcontrolled emission in ventialted rooms (C. Topp, 1999)
 NavierStokes simulations of airflow in rooms and around a human body (L. Voight, 2001)
 Numerical study of three dimensional turbulent flows in a habitat with coupled heat and mass transfer ( S. Luo, 2003)