A simplified system for indoor airflow simulation

Even though it is possible to accurately predict some features of airflow within ventilated thanks to advances in computationnal fluid dynamics (CFD) and computer power, it would consume a lot of time to get convergence.
Thus, in order to make predictions in short time on a personal computer it is important to develop simple models and methods to simulate indoor airflow. The main factors affecting the simulation speed are the method of describing inlet boundary conditions [1], turbulence model used [2], and the numerical method of solving the discrete equations [3].
The following sections will present an air supply opening model (ASOM) called «N-point ASOM» and a new numerical method of solving algebraic equations called error pre-treatment method. Together with an existing zero-equation turbulence model, the simplified simulation system can quickly predict indoor airflow with acceptable accuracy for engineering applications.

1. Project context

The 4fastsim-ibat project aims to reduce and control energy consumption in existing buildings while working on identifying potential energy-saving and testing their efficiency before any improvement work is done.

This project is a collaboration between two engineering companies: Cemosis and Synapse-Concept.

Cemosis was created in January 2013 by Christophe Prud’homme and is hosted by IRMA (the Institute of Advanced Mathematical Research). Cemosis is the Strasbourg Centre for Modelling and Simulation. It offers expertise in Modeling Simulation and Optimization (MSO), Data Science, Big Data, Smart Data (DS), High Performance Computing, Parallel Computing, Cloud Computing (HPC) and in Signal and Image processing (SI).

Synapse-Concept is a company specialised in engineering and technical studies. This company was created in November 1999. The main fields of the company are Digital Simulation, Energy savings, Air and Water Care, Laser scanning and Building Intelligence Modelling.

2. Presentation of the internship

The objective of this internship is to deepen the study of the 0-equation model which had been approached during the project of the second semester of the master 1 CSMI that Mariam Grigoryan, Anita Klein and myself did.

  • Reading and detailed description of the article "A simplified system for indoor airflow simulation" [4].

    • Models (fluid + aerothermal)

    • Variational formulation

    • Benchmarks

  • Study of the turbulence model from a numerical point of view.

  • Study of stabilization.

  • Understand the use of the fluid and heat-fluid toolboxes.

I worked under the supervision of Vincent Chabannes.

3. Plan

References

  • [1] Nielsen PV. Description of supply openings in numerical models for room air distribution. ASHRAE Transactions 1992;98(1):963–71.

  • [2] Xu Weiran. New turbulence models for indoor airflow simulation. Ph.D. thesis, Massachusetts Institute of Technology, USA, 1998.

  • [3] Liu Chaoqun. Multigrid method and application in computational fluid dynamics. Beijing: Tsinghua University Press, 1995 [in Chinese].

  • [4] Chen Qingyan, Xu Weiran. A Simplified Method for Indoor Airflow Simulation. Energy and Building, Massachusetts Institute of Technology, 1997.