Runner cone boundary layer control
2007 (English)In: Proceedings of the 2nd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems, Timisoara,Romania, October 24-26, 2007 / [ed] R. Susan-Resiga; S. Bernad; S. Muntean, Timişoara, 2007, 153-158 p.Conference paper (Refereed)
The runner cone plays an essential role in the performance of elbow draft tube and de facto of low head machines. An earlier separation on the runner cone deteriorates the pressure recovery and thus the overall efficiency of the machine. Control of the separation point on the runner cone is therefore of interest to improve efficiency at any regime. Onealternative to control the separation on the runner cone may be to rotate the runner cone with a different angular velocity than the runner blades. In the present work, the effect of runner cone angular rotation on elbow draft tube, typical in Kaplan turbine, is investigated using numerical simulations. The Turbine-99 test case (T-99) is used as benchmark at the top of the propeller curve. Simulations are performed for 4 different angular rotations: -595(stipulated in T-99), 0, +600 and +1200 rpm. The results indicate a delay of the separation on the cone at 0, +600 and +1200 rpm. The mean pressure recovery increases in all cases. The improvement reaches 6.6 % for the mean pressure recovery for an angular velocity of +600 rpm where separation disappear, while the loss factor decreases with 23.6 %.
Place, publisher, year, edition, pages
Timişoara, 2007. 153-158 p.
, Transaction of Mechanics, Scientific Bulletin of the Politehnica University of Timisoara, Romania, ISSN 1224-6077 ; 52(66)
Research subject Fluid Mechanics
IdentifiersURN: urn:nbn:se:ltu:diva-34823Local ID: 920beeb0-86f4-11dc-a4a5-000ea68e967bOAI: oai:DiVA.org:ltu-34823DiVA: diva2:1008074
IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems : 24/10/2007 - 26/10/2007
Godkänd; 2007; 20071030 (cervante)2016-09-302016-09-30Bibliographically approved