农业工程学报
農業工程學報
농업공정학보
2013年
17期
47-53
,共7页
赵亚萍%廖伟丽%李志华%阮辉%罗兴锜
趙亞萍%廖偉麗%李誌華%阮輝%囉興锜
조아평%료위려%리지화%원휘%라흥기
水轮机%优化%流场%C型和S型叶片%流动特性%能量特性
水輪機%優化%流場%C型和S型葉片%流動特性%能量特性
수륜궤%우화%류장%C형화S형협편%류동특성%능량특성
turbines%optimization%flow field%C-type and S-type blades%flow characteristic%energy performance
为了研究不同叶片进出口边形状及位置对贯流式水轮机内部的流动特性及机组能量特性所产生的影响,并为贯流式水轮机叶片的水力设计提供参考,该文基于某4叶片灯泡贯流式水轮机模型机,利用ANSYS-Bladegen对转轮叶片进行优化设计,并通过数值研究的方法对优化前(C 型叶片)和优化后(S 型叶片)的贯流式水轮机进行流场分析和性能评估,以揭示2种形式的叶片几何参数差异所引起的水轮机内流动特性及水轮机能量特性的差异。研究结果表明:S型叶片因其进出口边位置低于C型叶片,因此流道内速度矩的消耗位置较低,转轮出口环量分布规律也呈S型分布;C型叶片具有较大的叶栅稠密度及包角,叶片表面低压区较小,相反S型叶片叶栅稠密度及叶片包角较小,叶片正背面压差较大,因此转轮能量转换能力优于C型叶片,同时S型的出水边有效的减小了转轮出口的低压区,有助于改善尾水管内的流动特性;叶片进出水边对转轮内的水流具有导流作用,且流量越小,这种趋势越明显,S 型叶片进水边形状有将水流导向轮缘的趋势,水流在流道内的流量分配也呈近似 S型分配;S型叶片叶栅排挤作用减小,转轮内的水力损失、转轮出口环量损失及尾水管水力损失也明显小于C型叶片,因此其整体能量特性优于C型叶片。
為瞭研究不同葉片進齣口邊形狀及位置對貫流式水輪機內部的流動特性及機組能量特性所產生的影響,併為貫流式水輪機葉片的水力設計提供參攷,該文基于某4葉片燈泡貫流式水輪機模型機,利用ANSYS-Bladegen對轉輪葉片進行優化設計,併通過數值研究的方法對優化前(C 型葉片)和優化後(S 型葉片)的貫流式水輪機進行流場分析和性能評估,以揭示2種形式的葉片幾何參數差異所引起的水輪機內流動特性及水輪機能量特性的差異。研究結果錶明:S型葉片因其進齣口邊位置低于C型葉片,因此流道內速度矩的消耗位置較低,轉輪齣口環量分佈規律也呈S型分佈;C型葉片具有較大的葉柵稠密度及包角,葉片錶麵低壓區較小,相反S型葉片葉柵稠密度及葉片包角較小,葉片正揹麵壓差較大,因此轉輪能量轉換能力優于C型葉片,同時S型的齣水邊有效的減小瞭轉輪齣口的低壓區,有助于改善尾水管內的流動特性;葉片進齣水邊對轉輪內的水流具有導流作用,且流量越小,這種趨勢越明顯,S 型葉片進水邊形狀有將水流導嚮輪緣的趨勢,水流在流道內的流量分配也呈近似 S型分配;S型葉片葉柵排擠作用減小,轉輪內的水力損失、轉輪齣口環量損失及尾水管水力損失也明顯小于C型葉片,因此其整體能量特性優于C型葉片。
위료연구불동협편진출구변형상급위치대관류식수륜궤내부적류동특성급궤조능량특성소산생적영향,병위관류식수륜궤협편적수력설계제공삼고,해문기우모4협편등포관류식수륜궤모형궤,이용ANSYS-Bladegen대전륜협편진행우화설계,병통과수치연구적방법대우화전(C 형협편)화우화후(S 형협편)적관류식수륜궤진행류장분석화성능평고,이게시2충형식적협편궤하삼수차이소인기적수륜궤내류동특성급수륜궤능량특성적차이。연구결과표명:S형협편인기진출구변위치저우C형협편,인차류도내속도구적소모위치교저,전륜출구배량분포규률야정S형분포;C형협편구유교대적협책주밀도급포각,협편표면저압구교소,상반S형협편협책주밀도급협편포각교소,협편정배면압차교대,인차전륜능량전환능력우우C형협편,동시S형적출수변유효적감소료전륜출구적저압구,유조우개선미수관내적류동특성;협편진출수변대전륜내적수류구유도류작용,차류량월소,저충추세월명현,S 형협편진수변형상유장수류도향륜연적추세,수류재류도내적류량분배야정근사 S형분배;S형협편협책배제작용감소,전륜내적수력손실、전륜출구배량손실급미수관수력손실야명현소우C형협편,인차기정체능량특성우우C형협편。
We studied the influence of different shapes and positions of the leading edge and trailing edge and geometric parameters of blades on the internal flow characteristics and energy characteristics of a bulb turbine, and provided a reference for the hydraulic design of bulb turbine blades and other, similar turbines. In this paper, the optimization of the blade was carried out by the use of ANSYS-Bladegen for a model bulb turbine with four blades. The flow field analysis and performance evaluation for a bulb turbine with the initial blade (C-type blade) and the optimized blade (S-type blade) were conducted numerically to reveal the influence that the two blade configurations with different geometric parameters have on the turbine flow characteristics and hydraulic energy performance, especially to analyze the hydraulic losses in each part of flow passage caused by the difference in blade geometry. The results show that for the S-type blade, due to the leading edge and trailing edge of blade are below the C-type’s, the consumption location of the velocity moment of the blade in the meridional flow passage is also lower than its [need a noun here], and the velocity moment distribution after the runner is also S-shaped. The flow from the guide vanes could be fully developed before entering the runner, which will help reduce the hydraulic losses in the runner. The larger cascade density and blade wrap angle of the C-type blade made the cavitation performance better than the S-type blade, and the area of low pressure on the blade is small, because of the small cascade density and blade wrap angle for the S-type blade, the pressure difference between the pressure side and suction side of the blade is large, so the energy conversion capability is better than the C-type’s. The low-pressure region at the outlet of the runner is reduced effectively, which helps to improve the flow characteristics in the draft tube. The leading edge and trailing edge of the blade could play a guidance role to the flow in the flow passage, and this effect is more obvious at low mass flow rate operation conditions. The S-type leading edge shape of the blade could direct the flow to the chamber of the runner, the discharge distribution in the runner shows a similar S-type;S-type runner has small cascade crowding role relative to the C-type, this type of blade could reduce the hydraulic losses in runner, the circulation loss at the outlet of the runner and efficiency loss of the draft tube effectively, and the energy characteristics are superior to the C-type blade.