涡轮动叶叶型公差对喉道面积的影响

Effects of Turbine Blade Airfoil Tolerances on Turbine Throat Area

中文关键词:  涡轮动叶  喉道面积  叶型公差  随机分析  位置度  扭转角  轮廓度  航空发动机

英文关键词:turbine blade  throat area  airfoil tolerance  stochastic analysis  position tolerance  twist angle  profile tolerance  aeroengine

中文摘要:

      为精确控制涡轮动叶喉道面积，减小喉道面积偏离设计值对涡轮性能的影响，以GE公司某高压涡轮1级动叶为研究对 象，提出了基于叶型位置度、扭转角、轮廓度、缘板轮廓度的动叶喉道面积评估方法。按航空工业标准（HB 5647-98）给定了上述 参数的公差，分析了其对动叶喉道面积的影响，并采用随机分析方法研究了涡轮动叶喉道面积偏差分布。结果表明：当叶型沿轴 向、周向偏移时，由于对叶片左右两侧喉道宽度的作用效果相反，因此叶片喉道面积变化不大于±0.005%。叶型扭转及轮廓度偏 差对叶片喉道面积影响显著。当叶根、叶中、叶尖叶型分别扭转0.1°时，叶片喉道面积分别变化0.13%、0.14%和0.15%；当叶背侧 轮廓或尾缘轮廓变化0.1 mm时，叶片喉道面积变化0.08%；当下缘板轮廓度变化0.1 mm时，叶片喉道面积变化0.06%。当叶型尺 寸参数均符合其公差范围内的正态分布时，动叶喉道面积偏差也服从正态分布，±3倍标准差对应的喉道面积变化为理论喉道面 积的±0.91%。

英文摘要:

      To accurately control turbine blade throat area, mitigate the negative effect of turbine blade throat area deviation on turbine performance, taking the 1st stage blade of a GE high pressure turbine as the research object, a turbine blade throat area calculating method based on airfoil position tolerance, airfoil twist angle tolerance, airfoil profile tolerance, and endwall profile tolerance was proposed. Initial tolerances for the above-mentioned parameters were set according to the aviation industry standard (HB 5647-98), and detailed analyses were conducted to reveal their effects on the throat area. A stochastic analysis method was applied to study the deviation distribution of throat areas. The results show that the airfoil positions have little effect on the throat area due to their opposite effects on throat widths of left and right passages, the variations of throat areas are no more than ±0.005% when airfoils deviate in axial or circumferential direction. In contrast, airfoil twist angle and airfoil profile deviation significantly affect the throat area. When the airfoils of the hub, mid and tip sec? tions are rotated 0.1 degrees, the throat areas vary by 0.13%, 0.14%, and 0.15%, respectively. When the profile of the suction side and trail? ing edge vary by 0.1mm, the throat area varies by 0.08%. When the endwall profile varies by 0.1mm, the throat area varies by 0.06%. When the airfoil size parameters all conform to normal distributions within their tolerance range, the deviations of throat areas also conform to normal distribution, with its ±3 standard deviations equal to ±0.91% of the nominal throat area.