竖轴变攻角潮流发电水轮机性能预报流管模型研究

Streamtube models for performance prediction of vertical-axis variable-pitch turbine for tidal current energy conversion

为寻求一种快速可靠地预报竖轴变攻角直叶片潮流/河流水轮机性能的方法,给出了计算变攻角直叶水轮机水动力性能的单盘面—单流管(SDST)、双盘面—单流管(DDST)、单盘面—多流管(SDMT)和双盘面—多流管(DDMT)模型公式以及叶片转动效应的修正方法.计算和试验比较表明:低速比情况下,这4种修正的流管模型均可有效预报变攻角水轮机的能量系数;在水轮机正常工作的较高速比情况下,单盘面模型误差大,而双盘面模型与试验吻合良好,DDMT模型具有预报水轮机性能和叶片受力的优势,适合于快速进行变攻角水轮机的水动力优化设计和结构分析.

A fast reliable theoretical method was sought to predict the performance of the variable-pitch turbines for renewable tidal-current energy conversion. Four Streamtube models (single-disk single-streamtube SDST, double-disk single-streamtube DDST, single-disk multi-streamtube SDMT and double-disk multi-streamtube DDMT) based on the momentum theory with the modification of the blade rotating effect were described and compared. The numerical results based on the present modified streamtube models were compared with the experimental data, which showed that all 4 models were able to predict the energy coefficients of the variable-pitch turbines at lower tip-speed ratios, but the double-disk model was better at higher tip-speed ratios. The double-disk multi-streamtube model is more fit for the performance optimal design and structure analysis in the straight blade variable-pitch turbines.