TY - GEN
T1 - 3D-numerical optimisation of an asymmetric orifice in the surge tank of a high-head power plant
AU - Gabl, R.
AU - Achleitner, S.
AU - Neuner, J.
AU - Götsch, H.
AU - Aufleger, M.
PY - 2011/1/1
Y1 - 2011/1/1
N2 - In this presented work, the results of 3D-numerical investigations will be utilized to improve the 1D-numerical calculation of water hammer and surge tanks of high-head power plants. Usually, tabular values are used to quantify local head losses as a first approach. For existing high head power plants, the coefficients can be calibrated based on measurements. In a planning stage, physical laboratory tests and 3D-numerical simulations provide an alternative to assess loss quantities. In case of the presented work, a 3D simulation using ANSYS-CFX is carried out to calculate the local head loss coefficients. Furthermore, the investigated orifice is optimised for stationary and non-stationary cases. The present investigations on an asymmetric orifice, which is located in an elbow and part of a restricted entry surge tank, have shown that the local loss coefficient for the numerical simulations is higher than the simplified theoretic approach (tabular value). The findings using a 3D numerical approach are in agreement with earlier laboratory experiments. Thus, the numerical method was applied to optimise the orifice geometry with respect to the asymmetric effects of the orifice and to minimise the construction costs.
AB - In this presented work, the results of 3D-numerical investigations will be utilized to improve the 1D-numerical calculation of water hammer and surge tanks of high-head power plants. Usually, tabular values are used to quantify local head losses as a first approach. For existing high head power plants, the coefficients can be calibrated based on measurements. In a planning stage, physical laboratory tests and 3D-numerical simulations provide an alternative to assess loss quantities. In case of the presented work, a 3D simulation using ANSYS-CFX is carried out to calculate the local head loss coefficients. Furthermore, the investigated orifice is optimised for stationary and non-stationary cases. The present investigations on an asymmetric orifice, which is located in an elbow and part of a restricted entry surge tank, have shown that the local loss coefficient for the numerical simulations is higher than the simplified theoretic approach (tabular value). The findings using a 3D numerical approach are in agreement with earlier laboratory experiments. Thus, the numerical method was applied to optimise the orifice geometry with respect to the asymmetric effects of the orifice and to minimise the construction costs.
KW - 3D-numerical analysis
KW - Asymmetric orifice
KW - High-head power plant
KW - Surge tank
UR - http://www.scopus.com/inward/record.url?scp=84894435037&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84894435037
T3 - 34th IAHR Congress 2011 - Balance and Uncertainty: Water in a Changing World, Incorporating the 33rd Hydrology and Water Resources Symposium and the 10th Conference on Hydraulics in Water Engineering
SP - 2428
EP - 2435
BT - 34th IAHR Congress 2011 - Balance and Uncertainty
PB - International Association for Hydro-Environment Engineering and Research (IAHR)
T2 - 34th IAHR Congress 2011 - Balance and Uncertainty: Water in a Changing World, Incorporating the 33rd Hydrology and Water Resources Symposium and the 10th Conference on Hydraulics in Water Engineering
Y2 - 26 June 2011 through 1 July 2011
ER -