采用CFX软件对某600 MW空冷汽轮机低压缸内末级流道内湿蒸汽或工质的流动规律进行数值研究。结果表明:在同一质量流量工况下,随着背压的升高,末级动叶上的脱流越来越严重。在背压为11 k Pa(额定背压)工况时,叶片上未出现脱流现象。随着...采用CFX软件对某600 MW空冷汽轮机低压缸内末级流道内湿蒸汽或工质的流动规律进行数值研究。结果表明:在同一质量流量工况下,随着背压的升高,末级动叶上的脱流越来越严重。在背压为11 k Pa(额定背压)工况时,叶片上未出现脱流现象。随着背压的升高,动叶叶片根部脱流区域未变,由叶根至5%叶高处,而顶部脱流区域增大,由90%叶高至叶顶处变为70%叶高至叶顶处。同一背压下,随着质量流量的减小,脱流区在叶顶处明显增大,可以扩展到70%叶高至叶顶处,背压升高或流量降低加剧了动叶上的径向流。展开更多
Experiments have been performed to investigate the effect of mainstream turbulence on the three-dimensional distribution of the full coverage film cooling effectiveness for two enlarged actual twisted vanes with cylin...Experiments have been performed to investigate the effect of mainstream turbulence on the three-dimensional distribution of the full coverage film cooling effectiveness for two enlarged actual twisted vanes with cylindrical or shaped holes. The film cooling effectiveness was measured by transient liquid crystal technique at mainstream turbulence intensities of 2%, 9% and 15%. The mass flow rate ratios range from 5.5% to 12.5%. There are 3, 8 and 7 rows of film holes on the suction side, leading edge and pressure side, respectively. Results show that for the cylindrical hole vane the high mainstream turbulence intensity decreases the film cooling effectiveness in the top region and down region of pressure side in the low mass flow rate ratio of 5.5%, while the effect is opposite in the high mass flow rate ratio of 12.5%. The film cooling effectiveness in the middle region of pressure side decreases obviously with the increase of the turbulence at the low mass flow rate ratio of 5.5%, while the influence of increasing turbulence weakens gradually with the increase of mass flow rate ratio. Moreover, the high mainstream turbulence improves the film cooling effectiveness in the further downstream of the holes on suction side at the high mass flow rate ratio of 12.5%. For the shaped hole vane, the increase of mainstream turbulence decreases the film cooling effectiveness at all mass flow rate ratios. This study reveals the influence rule of the mainstream turbulence on the film cooling effectiveness in the different regions of the three-dimensional vane surface. The results would guide the designs of engineering heat transfer with application in gas turbine blade/vane cooling.展开更多
文摘采用CFX软件对某600 MW空冷汽轮机低压缸内末级流道内湿蒸汽或工质的流动规律进行数值研究。结果表明:在同一质量流量工况下,随着背压的升高,末级动叶上的脱流越来越严重。在背压为11 k Pa(额定背压)工况时,叶片上未出现脱流现象。随着背压的升高,动叶叶片根部脱流区域未变,由叶根至5%叶高处,而顶部脱流区域增大,由90%叶高至叶顶处变为70%叶高至叶顶处。同一背压下,随着质量流量的减小,脱流区在叶顶处明显增大,可以扩展到70%叶高至叶顶处,背压升高或流量降低加剧了动叶上的径向流。
基金the financial support from National Basic Research Program of China(China 973 Program)under number of 2013CB035702
文摘Experiments have been performed to investigate the effect of mainstream turbulence on the three-dimensional distribution of the full coverage film cooling effectiveness for two enlarged actual twisted vanes with cylindrical or shaped holes. The film cooling effectiveness was measured by transient liquid crystal technique at mainstream turbulence intensities of 2%, 9% and 15%. The mass flow rate ratios range from 5.5% to 12.5%. There are 3, 8 and 7 rows of film holes on the suction side, leading edge and pressure side, respectively. Results show that for the cylindrical hole vane the high mainstream turbulence intensity decreases the film cooling effectiveness in the top region and down region of pressure side in the low mass flow rate ratio of 5.5%, while the effect is opposite in the high mass flow rate ratio of 12.5%. The film cooling effectiveness in the middle region of pressure side decreases obviously with the increase of the turbulence at the low mass flow rate ratio of 5.5%, while the influence of increasing turbulence weakens gradually with the increase of mass flow rate ratio. Moreover, the high mainstream turbulence improves the film cooling effectiveness in the further downstream of the holes on suction side at the high mass flow rate ratio of 12.5%. For the shaped hole vane, the increase of mainstream turbulence decreases the film cooling effectiveness at all mass flow rate ratios. This study reveals the influence rule of the mainstream turbulence on the film cooling effectiveness in the different regions of the three-dimensional vane surface. The results would guide the designs of engineering heat transfer with application in gas turbine blade/vane cooling.
