Validation of a method for fluid flow rate measurement in square ducts by means of laser velocimetry

The paper deals with the introduction of an alternative method for the evaluation of the fluid flow rate through a square pipe, by directly measuring the flow mean velocity at a fixed location in the section area. The authors of this paper have previously introduced a way for the evaluation of the fluid flow rate, by measuring a single point flow velocity in square pipes. In this study, the authors perform a series of considerations aimed at the validation of the proposed methodology, by comparing it with prescribed procedures described by ISO 3966:2008 standard. In this standard a method for the evaluation of fluid flow rate (under specific fluid dynamic conditions) is stated from velocity measurements performed in a-priori fixed points (in a given test section and to be defined according to the cross-section shape), using a static Pitot-tube (or equivalent equipment). In this work, the authors validate the proposed simplified method against the Log-Thebycheff procedure (according to the same standard). A Laser Doppler Anemometer (LDA) has been used.