Surface heat transfer measurement

What is it about?

In various applications it is required to measure the heat transfer coefficient at the surface of a solid material (like quenching or heating). Generally the heat transfer coefficient depends on the surface temperature and varies with the position on the surface with respect to the heating or cooling device. Therefore it is required to measure the time dependent surface temperature and heat flux density simultaneously. In experimental facilities it is often not possible to directly measure the surface temperature and heat flux density, because the surface is not accessible and the placement of a sensor at the solid surface changes the surface geometry, which disturbs the flow conditions at the surface in case of a cooling liquid or gas. In such cases often one or more immersed temperature sensors are used in combination with inverse modelling: The heat transfer equation is used to determine both heat flux and temperature at the surface based on the measured temperature(s) of the immersed sensor(s). The main topic of the article is to analyse the accuracy of such a measurement method and the influence of process parameters like sensor depth, sensor noise level, sampling rate, heat flux density amplitude and cooling/heating process duration.

Featured Image

Why is it important?

In most cases it is very important to carefully adjust the process parameters in order to obtain reliable and accurate results. Additionally the proper selection of the regularisation parameter required for the inverse problem solution is analysed.

Perspectives