000			02970nam a2200397 4500
005			20260817162014.0
008			200598 th eng
035			_a.b10063742
099		9	_aAIT Thesis no.WA-85-53
100	0		_aAdith Suthinsak
245	1	0	_aAir entrainment from aeration device
260			_aBangkok : _bAsian Institute of Technology, _c1985
300			_a93 p.
490	1		_aThesis ; _vno. WA-85-53
500			_aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology
502			_aThesis (M.Eng.) - Asian Institute of Technology, 1985
520			_aCavitation erosion at the surface of the hydraulic structure subjected to the high velocity flow is caused by the surface irregularities. A successful and cheap method to prevent the erosion is to supply an amount of air into the flow through an aeration device. An experimental study on the phenomena of the air entrainment from aeration device was carried out in the hydraulic model of two types of device, namely; (i) plane groove type and, (ii) combined groove-deflector type. Air concentration at the chute bottom from the groove type is found too low to protect the surface from cavitation erosion. For the combined type the efficiency is much improved, air concentration found in the flow downstream of the jet impingement shows a typical distribution. A conceptual model was developed from the "Mixing length" theory of the velocity distribution and the free jet assumption to determine the air flow from the device. A linear relationship of the measured air concentration and the air discharge estimated from the model is found. A Model of aeration device with 1:2 scale ratio was constructed according to the Froude law of similarity. The measured air concentration is very low comparing with the prototype result, the model size is considered too small to be used for the purpose of comparison.
650		0	_aWater _xAir entrainment
650		0	_aCavitation
700	0		_aPrida Thimakorn, _eChairperson
700	0		_aTawatchai Tingsanchali, _eExamination Committee
700	1		_aWang, Tsan-Wen, _eExamination Committee
710	2		_aThe Government of France, _eScholarship Donor
810	2		_aAsian Institute of Technology. _tThesis ; _vno. WA-85-53
856			_3Full-Text _uhttp://203.159.5.9/ait-thesis/detail.php?q=B20183
907			_a.b10063742 _bmnait _cs
902			_a240409
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909			_aBarcode : 30050120573323 _bCREATED : 2014-02-04 _cRECORD # : i12785179 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
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