Numerical Study On Flow And Heat Transfer Of Internal Spillover Ribs In Gas Turbine Blades

Under the situation of increasing electricity power demand and conforming to the trend of energy saving and emission reduction,New energy power generation has been the rapid development.The gas generation develops fast,and especially the superiority of Gas-Steam combined cycle generation unit is more obvious.The efficiency of current gas turbine is improved by increasing the inlet temperature before the turbine.But due to the restrictions of material development,improving cooling structure and modes are usually used to intensive the cooling effect now.Therefore,that the research of heat transfer and improvement of cooling structure in the internal blade of gas turbine is very improvement.The article simplifies the straight channel portion of serpentine cooling channel that is inside the gas turbine blade to become straight channel with square cross-section,which has spoiler ribs.This article researches the different cooling structure parameters that impacts on heat transfer and flow characteristics of the channel by numerical study.And the parameters include the internal spoiler ribs' oblique angle of straight channel,rib pitch-to-heifht ratio,and the aspect ratio of the channel.The distribution of channel average Nu,streamline distribution and cooling efficiency diversification can be obtained wih the numerical computation.With the global optimization to the scope of the design parameters of various cooling structures on the basis of this study,the research can provide the basis for future design.The numerical result shows that when spoiler ribs' oblique angle increases,theoverall heat transfer effect of straight cooling channel increases,then decreases;the intergrated cooling efficiency of straight cooling channel decreases according to the structure research of spoiler ribs at inlet Reynolds number of 20000.The overall effect of heat transfer and integrated cooling efficiency of straight cooling channels with ribs both are functions with diversion angles.As the ribs' oblique angle is the optimization goal,the channel that the diversion angle is 46.34o overall effect of heat transfer is best and the channel integrated cooling efficiency is optimal when the diversion angle is 36.57o in the range of 30oto70o.Besides the article put the channel structure into research,the overall effect of heat transfer of cooling channel with ribs appear the trend of increasing.The integrated cooling efficiency of cooling channel with ribs appear the trend of firstly increasing and then gradually decreasing,and both are functions with W/H at inlet Reynolds number of 20000;As the W/H is the optimization object,the overall effect of heat transfer of the channel is best when the aspect ratio is 5,the channel integrated cooling efficiency is optimal when the aspect ratio is 0.44 in the range of1/5?W/H?5.The whirlpool on the channel that the channel aspect ratio is small can not cover the entire cross-section adequately,but the whirlpool on the channel that the aspect ratio is large could be enough to affect the entire channel space.Meanwhile,it enhances the effect of heat transfer and flow loss at the same time with ribbed wall's width increasing.