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Aeration in a spillway shaft | |
Author | Shrestha, Ganesh Bahadur |
Call Number | AIT Thesis no.WA-82-20 |
Subject(s) | Spillways |
Note | A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
Publisher | Asian Institute of Technology |
Abstract | Surface 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. |
Year | 1982 |
Type | Thesis |
School | School of Engineering and Technology |
Department | Department of Civil and Infrastucture Engineering (DCIE) |
Academic Program/FoS | Water Resources Research Engineering (WA) |
Chairperson(s) | Prida Thimakorn |
Examination Committee(s) | Christoph, Ing. Fried ; Apichart Anukularmphai |
Scholarship Donor(s) | Government of the Federal Republic of Germany (DAAD) |
Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1982 |