Secondary currents: Measurement and analysis

Abstract

RESUMENque describen la distribución de velocidades. Algunos fenómenos naturales que presentan estas funciones son los huracanes, los cuales son generados por las diferencias de presión; los ciclones, cuya fuente primaria de energía es el gradiente horizontal de temperatura, y los remolinos, que están ligados al gradiente de presión hidrostático. En el caso particular de los remolinos, éstos generan velocidades secundarias, las cuales son fenómeno también se observa en tornados, donde la fuerza centrífuga es mayor en la parte superior y luego va disminuyendo hacia el fondo, mientras que en los ríos se detecta particularmente en curvas y uniones -terización es fundamental. El objetivo de este estudio fue estimar las velocidades secundarias en la unión de dos ríos, a partir de mediciones de campo realizadas con medidores acústicos Doppler. Un segundo objetivo lo que su entendimiento ayudará a pronosticar cambios morfológicos en los ríos. ABSTRACTFluid dynamics has the purpose of understanding the movement of liquids and gases by functions that describe the distribution of velocities. Some natural phenomena that present these functions are hurricanes, generated by pressure differences; cyclones, developed by the horizontal temperature gradient; and eddies, associated with a hydrostatic pressure gradient. In the particular case of eddies, they generate addition, this phenomenon is observed in tornados, where the centrifugal force is greater in the upper layer and decreases towards the bottom, whereas the pressure gradient moves from a high to a low pressure; while in rivers it is detected particularly in bends or joins. Understanding the development of secondary hence their characterization is fundamental. The objective of this study was to obtain the secondary velocities developed as an effect of the union of two water currents, based on data acquired from Doppler Atmósfera 29 (1), 23-34 (2016(1), 23-34 ( ) doi: 10.20937/ATM.2016 © 2016 Universidad Nacional Autónoma de México, Centro de Ciencias de la Atmósfera. This is an open access article under the CC BY-NC-ND License (http://creativecommons.org/licenses/by-nc-nd/4.0/). 24 G. A. Priego-Hernández and F. Rivera-Trejo effect, a kind of results that are difficult to obtain in any other way. The flow mechanisms are related with erosion and sedimentation processes; therefore, understanding them might help to evaluate and predict morphological changes in rivers.

Flow Structure and Short-Term Riverbed Evolution in Curved Flumes

“…Vriend et al [1] conducted important field measurements in two successive sharply curved short bends in the river Dommel, the Netherlands. Priego-Hernández et al [2] performed field experiments in a natural river using a RiverCat ADCP from SonTek. Despite the importance of fieldwork, significant advances have also been made in the design of generalized models to investigate the flow structure and bed evolution characteristics in naturally curved rivers.…”

Adcp, Multi-Frequency Analysis for Flow Measurements in Rivers

“…Acoustic devices have become increasingly popular due to their efficiency, rapidity, and quality in flow measurement (Rennie et al, 2002;Muste et al, 2003;Winterwerp et al, 2006;Priego-Hernandez and Rivera-Trejo, 2016). They can measure velocity fields in three directions (3D) as well as quantifying sediment transport in suspension (Stone and Hotchkiss, 2007;Czuba et al, 2011;Thorne and Hurther, 2014;Ehrbar et al, 2017).…”

Hydrodynamics and measurement of natural currents in a plain river using acoustic Doppler equipment

“…Currently, these variables are measured using acoustic Doppler equipments, also known as acoustic Doppler current prolers (ADCPs) (Winterwerp et al 2006). ADCPs have become popular due to their eciency, speed and quality in ow measurement (Szupiany et al 2007, Priego-Hernández andRivera-Trejo 2016). They use frequencies greater than 25 kHz, which allows them to quantify the vibration of particles suspended in water.…”