Numerical study of the Winter-Kennedy method for relative transient flow rate measurement
2019 (English)In: IOP Conference Series: Earth and Environment, ISSN 1755-1307, E-ISSN 1755-1315, Vol. 405, no 1, article id 012022Article in journal (Refereed) Published
Abstract [en]
The Winter-Kennedy (WK) method is used to estimate relative flow rate using the differential pressure between two taps located at a radial section of a spiral casing (SC). It is widely used in index testing, for double regulated turbines optimization and sometimes for continuous discharge measurement in low head plants. This paper explores the possibility of using the WK method for relative transient flow rate measurements. A numerical model of a Kaplan model turbine from the penstock to the distributor has been developed. Unsteady RANS simulations with k-ω SST turbulence model are performed. Previously conducted experiments on the model turbine are used to validate the numerical results. In the simulations, the guide vanes (GVs) are closed from 26.5°, the best efficient point (BEP), to about 5° opening angle. Two azimuthal locations of the SC and four different WK configurations at each location are considered. The variation of the WK coefficients with time are investigated and compared to the ones at several stationary GV angles. The results showed a difference between the WK coefficients obtained at transient and stationary operations. However, there may be a possibility of using the WK method during transients by locating the pressure taps in appropriate locations for an acceptable variation of the WK coefficient from its BEP value.
The research has been funded by Swedish Hydropower Centre (SVC).
Place, publisher, year, edition, pages
Institute of Physics (IOP), 2019. Vol. 405, no 1, article id 012022
Keywords [en]
Winter-Kennedy, transient flow rate, hydro power
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
URN: urn:nbn:se:ltu:diva-77298DOI: 10.1088/1755-1315/405/1/012022ISI: 000562376700022Scopus ID: 2-s2.0-85078108189OAI: oai:DiVA.org:ltu-77298DiVA, id: diva2:1382924
Conference
IAHR International Workshop on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems, Stuttgart, October 9-11, 2019
Note
Konferensartikel i tidskrift
2020-01-072020-01-072020-09-25Bibliographically approved