Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
COMPARISSON BETWEEN THE DRAG REDUCTION IN AXIAL FLOW IN A CONCENTRIC ANNULI SPACE AND A TUBE
Submission Author:
Michell Luiz Costalonga , ES
Co-Authors:
Edson Soares
Presenter: Michell Luiz Costalonga
doi://10.26678/ABCM.ENCIT2016.CIT2016-0011
Abstract
The drag reduction (DR) by injection of small amounts of polymers, surfactants and fibers in turbulent flow has been studied for over seventy years. The applications include transport of liquids in pipelines, firefighting operations, bio-medicine among many others. Up to now, the most part of the works is related flow in tubes, channels and rotating geometries. In fact, as far as we known, there is not any paper in which the drag reducing flow in an annular space has been considered and this is the main point of the present work. It is worth noting that the axial flow in annular space occurs in many industrial applications and it is relevant in several processes, as those in the drilling industry. Hence, in attempt to understand the main difference between the drag reduction in annular spaces in comparison to other geometries, specially that one observed in tubes, we conducted a sequence of experiments by aid of an experimental setup. We used different polymer solutions with different concentrations. Our main data are presented in terms DR over the number of pass through our system. By doing so, in addition to DR, we were able to take into account the fall of efficiency caused by mechanical polymeric degradation, which was displaced in terms of the relative drag reduction. Such a relative drag reduction is the current value of DR divided by its maximum value obtained at the first pass through the system.
Keywords
drag reduction, concentric annuli space, polymeric solutions
