Fish Passage though Hydropower Turbines: Simulating Blade Strike using the Discrete Element Method
Abstract
mong the hazardous hydraulic conditions affecting anadromous and resident fish during their passage though turbine flows, two are believed to cause considerable injury and mortality: collision on moving blades and decompression. Several methods are currently available to evaluate these stressors in installed turbines, i.e. using live fish or autonomous sensor devices, and in reduced-scale physical models, i.e. registering collisions from plastic beads. However, a priori estimates with computational modeling approaches applied early in the process of turbine design can facilitate the development of fish-friendly turbines. In the present study, we evaluated the frequency of blade strike and nadir pressure environment by modeling potential fish trajectories with the Discrete Element Method (DEM) applied to fish-like composite particles. In the DEM approach, particles are subjected to realistic hydraulic conditions simulated with computational fluid dynamics (CFD), and particle-structure interactions—representing fish collisions with turbine blades—are explicitly recorded and accounted for in the calculation of particle trajectories. We conducted transient CFD simulations by setting the runner in motion and allowing for better turbulence resolution, a modeling improvement over the conventional practice of simulating the system in steady state which was also done here. While both schemes yielded comparable bulk hydraulic performance, transient conditions exhibited amore »
- Authors:
- Publication Date:
- Research Org.:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1178518
- Report Number(s):
- PNNL-SA-102698
WC0100000
- DOE Contract Number:
- AC05-76RL01830
- Resource Type:
- Conference
- Resource Relation:
- Conference: Proceedings of the 27th Symposium on Hydraulic Machinery and Systems (IAHR 2014), September 22-26, 2014, Montreal, Canada. IOP Conference Series: Earth and Environmental Science, 22(6):Paper No. 062010
- Country of Publication:
- United States
- Language:
- English
- Subject:
- CFD; fish; turbine; hydropower
Citation Formats
Richmond, Marshall C., and Romero Gomez, Pedro DJ. Fish Passage though Hydropower Turbines: Simulating Blade Strike using the Discrete Element Method. United States: N. p., 2014.
Web. doi:10.1088/1755-1315/22/6/062010.
Richmond, Marshall C., & Romero Gomez, Pedro DJ. Fish Passage though Hydropower Turbines: Simulating Blade Strike using the Discrete Element Method. United States. https://doi.org/10.1088/1755-1315/22/6/062010
Richmond, Marshall C., and Romero Gomez, Pedro DJ. 2014.
"Fish Passage though Hydropower Turbines: Simulating Blade Strike using the Discrete Element Method". United States. https://doi.org/10.1088/1755-1315/22/6/062010.
@article{osti_1178518,
title = {Fish Passage though Hydropower Turbines: Simulating Blade Strike using the Discrete Element Method},
author = {Richmond, Marshall C. and Romero Gomez, Pedro DJ},
abstractNote = {mong the hazardous hydraulic conditions affecting anadromous and resident fish during their passage though turbine flows, two are believed to cause considerable injury and mortality: collision on moving blades and decompression. Several methods are currently available to evaluate these stressors in installed turbines, i.e. using live fish or autonomous sensor devices, and in reduced-scale physical models, i.e. registering collisions from plastic beads. However, a priori estimates with computational modeling approaches applied early in the process of turbine design can facilitate the development of fish-friendly turbines. In the present study, we evaluated the frequency of blade strike and nadir pressure environment by modeling potential fish trajectories with the Discrete Element Method (DEM) applied to fish-like composite particles. In the DEM approach, particles are subjected to realistic hydraulic conditions simulated with computational fluid dynamics (CFD), and particle-structure interactions—representing fish collisions with turbine blades—are explicitly recorded and accounted for in the calculation of particle trajectories. We conducted transient CFD simulations by setting the runner in motion and allowing for better turbulence resolution, a modeling improvement over the conventional practice of simulating the system in steady state which was also done here. While both schemes yielded comparable bulk hydraulic performance, transient conditions exhibited a visual improvement in describing flow variability. We released streamtraces (steady flow solution) and DEM particles (transient solution) at the same location from where sensor fish (SF) have been released in field studies of the modeled turbine unit. The streamtrace-based results showed a better agreement with SF data than the DEM-based nadir pressures did because the former accounted for the turbulent dispersion at the intake but the latter did not. However, the DEM-based strike frequency is more representative of blade-strike probability than the steady solution is, mainly because DEM particles accounted for the full fish length, thus resolving (instead of modeling) the collision event.},
doi = {10.1088/1755-1315/22/6/062010},
url = {https://www.osti.gov/biblio/1178518},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Dec 08 00:00:00 EST 2014},
month = {Mon Dec 08 00:00:00 EST 2014}
}