University of Southampton OCS (beta), CAA 2012

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The Use of CFD to Understand Thermal Environments Inside Roman Baths: A Transdisciplinary Approach
Taylor Oetelaar, Clifton Johnston, David Wood, Lisa Hughes, John Humphrey

Last modified: 2011-12-18


            Computational fluid dynamics or CFD can provide another tool for the classical archaeologist to use when analyzing ancient structures. It is an engineering technique used to solve problems involving fluid flow and heat transfer. CFD can create an approximation of the temperature distribution, the velocity profiles, and other properties based on the geometry, materials, and environmental conditions that are supplied by archaeological research. Scholars have already applied CFD to the study of aqueducts in the Roman Empire, but there are many other possibilities for its use. This paper presents the benefits and problems of one of these possibilities – the caldaria of Imperial thermae – and provides some preliminary results from an initial case study.

            The caldarium, despite being the largest heated room in most complexes, has many unanswered questions surrounding its thermal atmosphere. For example, did the hot air rise and gather near the roof? Was the humidity localized above the pools? What air speed was created? The answers to these questions have many implications to the operation of the baths. This project uses CFD in conjunction with classical archaeology to address these questions in a case study of the Baths of Caracalla.

            CFD itself, however, is complex because multiple variables that affect the results and, as such, many analyses begin with a validation study of a documented example of similar geometry and purpose. For this project, the validation study is modelling the reconstructed bath in Turkey built for the television series NOVA, for which we have the exact dimensions, thereby eliminating archaeological uncertainty. The results from this model are extremely promising. The temperatures match those of presented by Yegül and Couch and velocities are low. Furthermore, they show that humidity did not affect the temperature drastically though it did create new air currents. Finally, the results prove the importance of an aspect often overlooked in previous thermal analyses – the doorway. The exchange with the next room is arguably the most important driving force for the environment inside the caldarium.



Yegul, F. K., & Couch, T. (2003). Building a Roman Bath for the Cameras. Journal of Roman Archaeology. 16, 153-177.


computational fluid dynamics; Roman thermae; thermal environments