【作者】 苏生；

【导师】 刘建军；

【作者基本信息】 中国科学院研究生院（工程热物理研究所） ， 工程热物理， 2008， 博士

【摘要】 先进的燃气轮机叶片冷却技术可以使叶片承受更高的透平进口燃气温度，增加冷却叶片的安全性和持久性，提高燃气轮机性能。本文对某重型燃气轮机透平中综合采用的带肋蛇形通道、涡流矩阵通道和叶尖孔等冷却结构进行了流动与换热特性研究。分别采用数值模拟和基于热色液晶瞬态测温技术的实验方法对单独的带肋直通道和涡流矩阵通道进行了研究，并在验证了数值模拟方法可靠性的基础上对旋转蛇行通道进行了数值研究，最后采用数值模拟方法对具有带肋蛇形通道、涡流矩阵通道和叶尖孔的动叶片进行了气—热耦合研究。带肋直通道中扰流肋片具有强化换热作用。在原始带有单一尺寸肋片通道中的适当位置加入小肋片，通道换热性能得到提高的同时，流动阻力系数也可能会下降，数值模拟与实验结果显示交替大小肋片通道具有较好的综合强化换热能力。在旋转非对称两流程蛇形通道中，从带肋壁面的换热系数和通道内的流动规律着手，对比相同尺寸模型的光滑蛇形通道与静止带肋蛇形通道的数值模拟结果，发现进口段中的单侧肋片对其中的流动与换热起主导作用；在出口段中，科氏力的作用逐渐显现，使通道中涡的形状发生变化，在局部地方使当地的涡系结构发生变化；在强化换热方面，旋转因素使出口段的前缘面和后缘面的换热能力都得到加强，科氏力使后缘面的加强幅度更大。影响涡流矩阵通道中流动与换热性能的主要几何参数有三个：肋宽-肋高比b/h、肋宽-肋间距比b/p和肋片倾斜角β。通过对七个模型的实验研究和数值模拟发现，通道的流动阻力系数随b/h值的增大而减小，随b/p值的增大而增大，随β的增大而增大，而换热能力随这三个参数的变化不呈单调变化趋势。某重型燃气轮机第一级透平动叶综合使用了上述带肋蛇形通道、涡流矩阵通道等冷却结构，并带有叶尖孔。通过改变模型中涡流矩阵通道的肋片尺寸、叶尖孔、叶尖内部间隙以及叶顶间隙等，考察各结构对冷却和流动带来的影响与作用。采用气—热耦合方法得到的结果显示各部分既分别展现自身特性，还相互产生影响。内冷结构对出口处的气流角、总温分布有一定的影响，对叶片负荷的影响不大。随着肋片宽度和间距的减小，对应区域叶片温度场趋于均匀。在考虑叶顶间隙的情况下，从叶尖孔喷出的冷气能对叶尖前缘和叶尖中部区域进行有效的冷却。叶尖内部间隙结构能促进涡流矩阵通道中靠吸力面一侧的子通道内的流动，改善对吸力面的冷却，在考虑叶顶间隙的情况下，从叶尖内部间隙流过的冷气能对叶尖尾缘进行十分必要和有效的冷却。更多还原

【Abstract】 Su Sheng (Engineering Thermophysics)Supervised by Professor Liu Jian-JunThe application of effective cooling technology can allow turbine blade to undergohigh gas temperature and can increase the blade security and durability,and also the gasturbine efficiency.In this dissertation,the fluid flow and heat transfer in typical internalcooling configurations of a gas turbine rotor blade,including rib-roughened duct orserpentine passage,and matrix cooling,were studied.Both numerical simulations andexperiments based on transient heat transfer technology with thermochromic liquid crystalwere carried out.The numerical method used for the simulations was validated byexperimental results.Conjugate heat transfer method was used to study the fluid flow andheat transfer in the turbine rotor blade.In the rib-roughened duct,ribs induce secondary flow and break up the flow boundarylayer,result in enhanced heat transfer on the ribbed walls.When a smaller rib is planted ina proper location between each two original ribs,better heat transfer can be obtained andthe fluid flow resistance may also be decreased.Both numerical and experimental resultsshow that the integrated heat transfer ability,considering both the heat transferenhancement and the pressure loss,can be improved.The heat transfer and fluid flow in a rotating unsymmetrical two-pass serpentinepassage were numerically studied.Compared to the results in smooth serpentine passageand stationary rib-roughened serpentine passage,ribs planted only on one wall as in theinlet passage play a dominant role on the fluid flow and heat transfer.The effects ofCoriolis force come out gradually in the outlet passage.Coriolis force changes the vortexshape in the outlet passage,even changes the vortex configuration in some places.Rotatingenhances the heat transfer on both the front edge and back edge in the outlet passage.Due to the effect of Coriolis force,the enhancement of heat transfer on the back edge is higherthan that on the front edge.Three geometrical parameters have significant impacts on fluid flow and heat transferin matrix cooling.The parameters are rib width to height ratio b/h,rib width to pitch ratiob/p and the rib incline angleβ.The numerical and experimental results of seven differentmodels show that smaller b/h,or bigger b/p or biggerβleads to higher flow resistance.However,the heat transfer ability on the rib-roughened walls does not increase or decreasein a monotone way.The fluid flow and heat transfer studies for the turbine rotor blade were carried out bychanging the rib scale of matrix cooling,including or excluding tip film cooling,tip innerclearance and tip clearance.Numerical results obtained by using conjugate heat transfermethod show that each configuration has its own characteristics and interactions amongconfigurations are also found.Internal cooling has some effects on the flow angle and totaltemperature distribution at blade outlet,however,has small effect on blade aerodynamicload.Smaller scale of rib width and pitch leads to more unique temperature distributions inthe corresponding blade area.When tip clearance is considered,cooling air ejected fromthe tip holes can cool the leading edge and middle part of the blade tip.Inner clearancenear the blade tip can improve the fluid flow in the matrix sub-channels lying on the bladesuction side,consequently the suction side can be better cooled.In addition,cooling airflowing through the inner clearance near the blade tip can cool the trailing edge at the tipnecessarily and effectively.更多还原