Research output: Contribution to journal › Article › peer-review
Vortex ropes in draft tube of a laboratory Kaplan hydroturbine at low load : an experimental and LES scrutiny of RANS and DES computational models. / Minakov, Andrey V.; Platonov, Dmitriy V.; Litvinov, Ivan V. et al.
In: Journal of Hydraulic Research, Vol. 55, No. 5, 03.09.2017, p. 668-685.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Vortex ropes in draft tube of a laboratory Kaplan hydroturbine at low load
T2 - an experimental and LES scrutiny of RANS and DES computational models
AU - Minakov, Andrey V.
AU - Platonov, Dmitriy V.
AU - Litvinov, Ivan V.
AU - Shtork, Sergey I.
AU - Hanjalić, Kemal
PY - 2017/9/3
Y1 - 2017/9/3
N2 - We report on the examination of several approaches to simulate computationally the unstable regime of a model Kaplan turbine operating at off-design load. Numerical simulations complemented by laboratory experiments have been performed for a 60:1 scaled-down laboratory turbine model using two Reynolds-averaged Navier–Stokes (RANS) models (linear eddy viscosity model (LEVM), and a Reynolds stress model (RSM), including realizable k-ε, k-ω SST, and LRR), detached eddy simulation model (DES), and large eddy simulation model (LES). Unlike the LEVM, the RSM, DES, and LES reproduced the mean velocity components and the intensities of their fluctuations and pressure pulsations well. The underperformance of the LEVM is attributed to the high eddy viscosity as a consequence of an excessive production of the turbulent kinetic energy due to the models’ inability to account for the turbulent stress anisotropy and the stress-stain phase lag, both naturally accounted for by the RSM. This led to a much larger modelled and a smaller resolved turbulent kinetic energy compared to those in the RSM.
AB - We report on the examination of several approaches to simulate computationally the unstable regime of a model Kaplan turbine operating at off-design load. Numerical simulations complemented by laboratory experiments have been performed for a 60:1 scaled-down laboratory turbine model using two Reynolds-averaged Navier–Stokes (RANS) models (linear eddy viscosity model (LEVM), and a Reynolds stress model (RSM), including realizable k-ε, k-ω SST, and LRR), detached eddy simulation model (DES), and large eddy simulation model (LES). Unlike the LEVM, the RSM, DES, and LES reproduced the mean velocity components and the intensities of their fluctuations and pressure pulsations well. The underperformance of the LEVM is attributed to the high eddy viscosity as a consequence of an excessive production of the turbulent kinetic energy due to the models’ inability to account for the turbulent stress anisotropy and the stress-stain phase lag, both naturally accounted for by the RSM. This led to a much larger modelled and a smaller resolved turbulent kinetic energy compared to those in the RSM.
KW - DES
KW - hydroturbine draft tubes
KW - LES
KW - pressure pulsation
KW - RANS
KW - vortex ropes
KW - TURBINE
KW - SIMULATION
KW - FREQUENCY PRESSURE PULSATIONS
KW - FLOW
UR - http://www.scopus.com/inward/record.url?scp=85018843476&partnerID=8YFLogxK
U2 - 10.1080/00221686.2017.1300192
DO - 10.1080/00221686.2017.1300192
M3 - Article
AN - SCOPUS:85018843476
VL - 55
SP - 668
EP - 685
JO - Journal of Hydraulic Research/De Recherches Hydrauliques
JF - Journal of Hydraulic Research/De Recherches Hydrauliques
SN - 0022-1686
IS - 5
ER -
ID: 10256547