管内圧力調整のための二段オリフィスにおける組合せ特性の解析と考察

DOI Web Site

書誌事項

タイトル別名
  • Analysis on the Characteristics of Dual Orifices for Pressure Control in Conduits
  • カンガイヨウ カンスイロ ノ アツリョク チョウセイ ニカンスルケンキュウ 2
  • Pressure dissipation in closed conduits used in irrigation system (II)
  • カンガイ用管水路の圧力調整に関する研究 (II)

この論文をさがす

抄録

The effect of orifice pressure dissipation is very effective in controlling pressure in closed conduits.<BR>In this paper, controlling pressure in closed conduits is discussed with the employment of dual orifices arranged in a series special consideration is given to determining the proper diameters for the dual orifices so that the required discharge and required pressure dissipation can be satisfied, and in an effort to make sure that the safety factors for each orifice to cavitation is equal.<BR>Incipient and critical cavitations are treated as the allowable limits for cavitation. The results are as follows:<BR>1) The optimal combination of the orifice to the pipe diameter ratio for the dual orifice system is given by<BR>_??_(1)<BR>where β is the orifice to the pipe diameter ratio, f (β) is the coefficient of head loss, and σal is the allowable limit of cavitation.The subscripts, 1 and 2, refer to the orifices arranged downstream and upstream, respectively.<BR>2) When incipient cavitation is used as the allowable limit for cavitation, σal is given by<BR>σal=4.5β+0.5...(2)<BR>when critical cavitation is used, <BR>σal=3.3β...(3)<BR>3) The optimal distributive ratio of head loss to dual orifices is given by (h2/h1) opt>1 in the system of optimal combination of the orifice to the pipe diameter ratio.Where h1 is the head loss caused by the orifice arranged downstream;h2 is the head loss upstream.Therefore, the optimal combination of orifices is obtained when the amount of pressure control for the orifice arranged upstream is greater than that of the orifice arranged downstream.<BR>4) The diagram for selecting the combination of the orifice to the pipe diameter ratio can be made by solving the above mentioned equation (1) of the optimal combination of orifice to pipe diameter ratio in the dual orifice system.

収録刊行物

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ