In-hive temperature evolution: comparison between measurements and simulations

Nowadays beekeepers are facing environmental challenges that threaten their profession. Bee colonies are under pressure of several factors: parasites (varroa mites), invasive species (hornets), chemicals and weather. We are studying the impact of hive geometry and materials on the in-hive temperature which is a key parameter since bees have to thermoregulate the brood nest for proper development. The initial aim is to understand and quantify thermal interactions between the environment and the hive, as well as heat transfer within the hive. We will then be able to advise beekeepers on possible actions to be taken to modify the temperature inside the hive, either upwards or downwards as needed.

For this purpose, an experimental apiary is equipped with 2 instrumented empty Dadant hives with several temperature and humidity sensors. The close environment of the hives is characterized using a set of sensors (temperature, irradiance, anemometer, infrared, etc.). A thermal model of the hive and its close environment was implemented using Octave software based on a library we have developed. This library allows various volumes to be defined using Finite Volume Method. These elements are then connected together using uniform or non-uniform thermal conductances. Heat radiation in the body part of the hive is introduced using the radiosity method.

This article presents the main assumptions and equations of the model. A comparison is then performed between simulations and measurements with environmental data used as model input. A sensitivity analysis is also conducted to identify the some influential parameters on in-hive temperatures.

This research was funded by the Agropolis foundation (HaBeeTaT project) and by the European Better-B project (101081444-Better-B) in the frame of European Programme HORIZON-CL6-2022-BIODIV-02-two stage on resilient beekeeping (2023-2027).

Work In Progress