Building a grey box model to model the energy and mass transfer in an imperfectly mixed fluid by using experimental data

A model concept has been developed and described in which a physical model is linked with a mathematical identification procedure to model the micro-environment (temperature and mass concentration) within an imperfectly mixed fluid (a ventilated space). The objective of this paper is to explain this new concept and to give experimental results that confirm the value of this approach. Experimental data are available as measured in a ventilated space for different values of the ventilation rate and heat supply with corresponding differences in the quantified air flow pattern and resulting measured and visualised position, shape and dimensions of the well mixed zones of temperature. Possibilities and problems are given to apply this technique to other variables and to apply it for control purposes.