Considering crop and animal production, IAQ, gas emissions, associated health effects and socio-economic problems, one of the biggest issues, these days, in Europe as well as in the world is to measure the ventilation rate of naturally ventilated buildings. Among various direct and indirect methods, the CFD approach can produce the most practical and timely solutions because of its outstanding potential for analyzing complex air flows. In this project, the candidate will develop a free simulation tool to predict the ventilation rate of naturally ventilated agricultural buildings, such as greenhouses and livestock houses. As next generation of CFD approaches, the free simulation tool, HNVR calculator, will be built of automated user interfaces and the CFD technique so that users can directly use the program without CFD experts in simulating the air flows in and around the buildings with convenience and stable accuracy of the results. Regarding the ventilation researches, the host institute, M3-BIORES in KU LEUVEN, has accumulated knowledge and experiences over the decades, whereas the applicant has been working on simulation research and its applications. Therefore the applicant will provide new perspectives on solving problems by bring the state-of-art knowledge and experience to the host institute. In addition, active knowledge transfer between them will create a synergetic effect on completing this project and enhance the European host Institute’s position at the forefront of advances in this field. This project will also encourage long term collaborations between the European host group and the Korean research group (Aero-Environmental and Energy Engineering Lab.) which is one of the biggest leading group in the field of agricultural engineering in Korea.