de Lima; Cleveland


Die Bodenkultur - Journal for Land Management, Food and Environment

Rui P. de Lima, Theodore G. Cleveland and Rita F. de Carvalho:

Infrared thermography as a heat tracer method for velocity
estimation in shallow flows

Summary

This work presents a technique that uses infrared thermography to estimate mean flow velocity, based on the time of travel of a heat tracer (hot water). A thermographic camera, installed above a flume, allows the visualization of the water surface temperature. When hot water is added to the flow, it appears in the footage as a bright mass moving downstream. This allows the quantification of its surface velocity, which corresponds to flow velocity (shallow flows). As a control, results were compared with the measurements obtained by an Acoustic Doppler Velocimeter. This technique is particularly suitable for measurements in shallow flows, where most common flow velocity equipment reveal some limitations due to incompatibilities with low water depths.

Key words: Infrared thermography, Flow velocity, Overland flow, Shallow flow, Heat tracer.