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035 _a.b10057870
099 9 _aAIT Thesis no.WA-82-20
100 1 _aShrestha, Ganesh Bahadur
245 1 0 _aAeration in a spillway shaft
260 _aBangkok :
_bAsian Institute of Technology,
_c1982
300 _ax, 85 p.
490 1 _aThesis ;
_vno. WA-82-20
500 _aA thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology
502 _aThesis (M.Eng.) - Asian Institute of Technology, 1982
520 _aSurface irregularities in the spillway shaft of high head, steep gradient and high flow velocity causes a serious cavitation damage. In order to prevent cavity erosion a numbers of methods were used and tested. Recently, it was found that erosion can be reduced effectively by the air-entrainment into the flow through the aeration grooves. An experimental study on the phenomena of aeration groove was carried out in the Hydraulic Model of Nam Chon Dam spillway. The Nam Chon Power Station is the major part of the Upper Quai Yai Hydroelectric Development Project. The scale of the model was derived from Froude Similarity Law. The conceptual model of air-water flow is developed according to the shear stress theory at the air-water interface. The experimental result gives acceptable agreement with the model. The results of pressure distribution along the bottom of the tunnel and air-entrainment through the aeration grooves indicate the necessity of all the grooves along the inclined shaft. Due to the negative pressure heads detected in some of the grooves, modifications in the design of the groove shape is required. The original spacing of the aeration grooves as given in prototype is found to be effective from the results of air concentration.
650 0 _aSpillways
700 0 _aPrida Thimakorn,
_eChairperson
700 1 _aChristoph, Ing. Fried,
_eExamination Committee
700 0 _aApichart Anukularmphai,
_eExamination Committee
710 2 _aGovernment of the Federal Republic of Germany (DAAD),
_eScholarship Donor
810 2 _aAsian Institute of Technology.
_tThesis ;
_vno. WA-82-20
856 _3Full-Text
_uhttp://203.159.5.9/ait-thesis/detail.php?q=B21394
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