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Title: The effects of sampling location and turbulence on discharge estimates in short converging turbine intakes

Abstract

Standards provide recommendations for best practices when installing current meters to measure fluid flow in closed conduits. A central guideline requires the velocity distribution to be regular and the flow steady. Because of the nature of the short converging intakes typical of low-head hydroturbines, these assumptions may be invalid if current meters are intended to be used to estimate discharge. Usual concerns are (1) the effects of the number of devices, (2) the sampling location and (3) the high turbulence caused by blockage from submersible traveling screens usually deployed for safe downstream fish passage. These three effects were examined in the present study by using 3D simulated flow fields in both steady-state and transient modes. In the process of describing an application at an existing hydroturbine intake at Ice Harbor Dam, the present work outlined the methods involved, which combined computational fluid dynamics, laboratory measurements in physical models of the hydroturbine, and current meter performance evaluations in experimental settings. The main conclusions in this specific application were that a steady-state flow field sufficed to determine the adequate number of meters and their location, and that both the transverse velocity and turbulence intensity had a small impact on estimate errors. However,more » while it may not be possible to extrapolate these findings to other field conditions and measuring devices, the study laid out a path to conduct similar assessments in other applications.« less

Authors:
; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1357717
Report Number(s):
PNNL-SA-122068
Journal ID: ISSN 1994-2060; WC0102000
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Engineering Applications of Computational Fluid Mechanics; Journal Volume: 11; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
virtual current meter (VCM); computational fluid dynamics (CFD); hydropower; turbine; intake

Citation Formats

Romero-Gomez, P., Harding, S. F., and Richmond, M. C. The effects of sampling location and turbulence on discharge estimates in short converging turbine intakes. United States: N. p., 2017. Web. doi:10.1080/19942060.2017.1313176.
Romero-Gomez, P., Harding, S. F., & Richmond, M. C. The effects of sampling location and turbulence on discharge estimates in short converging turbine intakes. United States. doi:10.1080/19942060.2017.1313176.
Romero-Gomez, P., Harding, S. F., and Richmond, M. C. Sun . "The effects of sampling location and turbulence on discharge estimates in short converging turbine intakes". United States. doi:10.1080/19942060.2017.1313176.
@article{osti_1357717,
title = {The effects of sampling location and turbulence on discharge estimates in short converging turbine intakes},
author = {Romero-Gomez, P. and Harding, S. F. and Richmond, M. C.},
abstractNote = {Standards provide recommendations for best practices when installing current meters to measure fluid flow in closed conduits. A central guideline requires the velocity distribution to be regular and the flow steady. Because of the nature of the short converging intakes typical of low-head hydroturbines, these assumptions may be invalid if current meters are intended to be used to estimate discharge. Usual concerns are (1) the effects of the number of devices, (2) the sampling location and (3) the high turbulence caused by blockage from submersible traveling screens usually deployed for safe downstream fish passage. These three effects were examined in the present study by using 3D simulated flow fields in both steady-state and transient modes. In the process of describing an application at an existing hydroturbine intake at Ice Harbor Dam, the present work outlined the methods involved, which combined computational fluid dynamics, laboratory measurements in physical models of the hydroturbine, and current meter performance evaluations in experimental settings. The main conclusions in this specific application were that a steady-state flow field sufficed to determine the adequate number of meters and their location, and that both the transverse velocity and turbulence intensity had a small impact on estimate errors. However, while it may not be possible to extrapolate these findings to other field conditions and measuring devices, the study laid out a path to conduct similar assessments in other applications.},
doi = {10.1080/19942060.2017.1313176},
journal = {Engineering Applications of Computational Fluid Mechanics},
number = 1,
volume = 11,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2017},
month = {Sun Jan 01 00:00:00 EST 2017}
}