NERI Technical report no. 541. Regulatory odour model development: Survey of modelling tools and datasets with focus on building effects. Olesen, H.R., Løfstrøm, P., Berkowicz, R. & Ketzel, M. 2005. 62 pp.

 

Summary

This report forms an initial part of a project on improving an atmospheric dispersion model. The dispersion model concerned (OML) is to be used for calculation of odour from animal production.

The OML model is used for regulatory applications in Denmark, and it is the candidate model to be used also in future in relation to odour problems and ammonia deposition due to animal farming. However, the model needs certain improvements and validation in order to be fully suited for these purposes.

The report represents a survey of existing literature, models and data sets. It includes a brief overview of the state-of-the-art of atmospheric dispersion models for estimating local concentration levels in general. However, the report focuses on some particular issues, which are relevant for the subsequent work on model improvements in relation to dispersion of odour from stables.

One issue of primary concern is the effect that buildings (stables) have on flow and dispersion. The handling of building effects is a complicated problem, and a major part of the present report is devoted to the treatment of building effects in dispersion models.

In the subsequent work within the current project, various paths will be followed. As a main path, the potential of integrating OML with PRIME will be explored. PRIME is separate model that specifically addresses building effects; it was developed in the USA during the late 90's.

There are various alternatives to that of using PRIME, and their merits will also be considered during the subsequent work with model development and assessment.

A second issue of concern to odour problems in general is how to deal with the complexities of odour perception and regulation. The report provides an introduction to this topic.

A third issue, which receives considerable attention throughout the report, is the question of obtaining data for model improvement and model assessment. This is necessary for the project, but it is by no means straightforward. Basically, there are three approaches to ob-tain data for model verification:

a) field measurements;

b) wind tunnel simulation;

c) data obtained by more detailed models than the one being inves-tigated, in particular CFD modelling.

 

All three approaches have limitations, so it is relevant to consider all of them - possibly in combination - when assessing model performance. The advantages and disadvantages of the three approaches are discussed, and the information is summarised in tabular form in the conclusion (Chapter 7).

 

Furthermore, the report provides an overview of relevant data sets for model assessment. A substantial number of data sets are mentioned; however, only a small number of these data sets will eventually be selected for actual use within the project.

In general, the present report is a tool to be used for subsequent work on model improvement and model assessment, with focus on the OML model.

 

Full report in pdf format (440 kB).