HNVR-Calculator

Handy Natural Ventilation Rate Calculator – Based on Computational Fluid Dynamics

< Marie Curie Actions – International Fellowship >

Overview



VENTILATION IN LIVESTOCK HOUSES AND GREENHOUSES


A well-controlled ventilation rate is essential to provide animals and plants in livestock houses and greenhouses with good environment while minimizing additional heating and cooling cost. The quantification of ventilation rate is crucial in terms of control of indoor air quality and emission of pollutants. Especially in naturally-ventilated buildings, measuring the ventilation rate is more elusive because of dynamic and complex air flow patterns induced by natural wind.

WHY DO WE NEED CFD SIMULATION?

Computational fluid dynamics (CFD) uses numerical methods to describe fluid flow. The result is a wealth of predictions for flow velocity, temperature and mass concentration.

CFD is a very compelling, non-intrusive, virtual modelling technique with powerful visualisation capabilities and has outstanding potential for analysing complex air flows with advantages of insight, foresight and efficiency.

However, CFD simulation requires a high level of technical expertise. Using a well-known commercial CFD package and hiring a CFD expert are usually costly. The reliability of CFD analysis has been a perennial problem and depends heavily on the skill and experience of the modeller.

WHAT IS "SYS" ?

  • “SYS (Simulate YourSelf)” is a CFD solution to automate pre, main and post processes of computational fluid dynamics simulations and to analyse ventilation performance of a naturally ventilated agricultural buildings

  • It consists of graphical user interfaces dealing with open-source OpenFOAM CFD packages and a visualisation toolkits

  • It provides simulation results of local ventilation effects as well as overall ventilation performance and shows graphical representations of results

  • It provides general users (consultant, researcher, company, university) with quick and practical solutions for ventilation performance and researchers with highly accurate computing solutions for scientific purposes

  • By simply designing your building, you can discover airflows and ventilation rates in your building

HOW DOES IT WORK?

OpenFOAM and ParaView Python were used for CFD simulation and visualisation respectively because they are free and open source software. The simulation tool was developed using Microsoft Visual Basic (VB) and Python to provide automation of general processes of the CFD simulation, such as building geometry, meshing and computing, and the GUI for users. Based on the input by the user, a computational domain with a cylindrical shape was built to realise 16 wind directions and filled with 3D meshes using the SnappyHexMesh technique. Two new steady-state solvers that involved physiological models for animals and plants were developed, and used to compute incompressible turbulent buoyant flows. A solver to calculate the ventilation effectiveness, such as the local mean age (LMA) and the local mean residual-life-time (LMR), was also developed and included in the simulation tool. The simulated results were shown to the user by the interactive visualisation interface based on the Visualisation Toolkit (VTK) source.

VISUALISATION

The final simulation results are shown as a report that describes ventilation rates at each ventilation openings and the overall ventilation rate, and as a 3D visualisation through the 3D interactive visualisation window. in the visualisation window, the user can zoom in, zoom out, move and rotate the viewpoint by keyboard and mouse. The LMA, LMR, velocity, pressure, temperature, turbulence quantities and airflow vectors can be displayed on the sliced plane, which can be controled by the user.

DOWNLOADS

tutorials

tutorial examples

Installation files

Program files (No installation version)

summary

Final report

Brochure

tutorials.pdf






summary.pdf
finalreport.pdf
brochure.pdf

CONTACT US

Scientist in Charge:

Daniel Berckmans

Division Head

M3-BIORES: Measure, Model & Manage Bioresponses

Katholieke Universiteit Leuven

Kasteelpark Arenberg 30, B-3001 Leuven, Belgium

http://www.M3-BIORES.com

Fellow:

Se-Woon Hong (hsewoon@jnu.ac.kr)

For any comments or questions concerning the project, send email