GOALI: Gas Turbine Blade Tip Leakage Flow and Heat Transfer: Strategies for Blade Tip Cooling

项目负责人：S. Ekkad和S. acharya该奖项旨在支持有关叶尖空气动力学和传热的基本问题的研究，并为燃气轮机行业提供改进叶尖冷却策略的指导，这将有助于提高叶片寿命，减少燃气轮机发动机的维护需求。这是路易斯安那州立大学和通用电气公司联合提交的一份GOALI提案。通用电气将主要负责技术转让和测试，使用工业标准程序，改进设计和概念，由路易斯安那州立大学提出的研究结果。实验研究将在一个五叶片线性叶栅上进行，该叶栅带有高压压缩空气流动设备，能够为发动机提供具有代表性的流动条件。模拟发动机典型的PT、rel、入口/PS、出口，以确保从压力面到吸力面真实的压力驱动泄漏流。本研究将使用二维涡轮叶片叶栅。五叶叶栅的中间叶片将设置一个典型的间隙。叶片与叶冠的相对运动将以运动带作为叶冠来模拟。速度和压力测量将在压力面和吸力面以及叶冠和叶尖区域获得。将使用萘升华技术在压力面、吸力面和尖端区域获得详细的质量/传热测量。将研究两种叶尖设计，平面和尖形。用于实验测试的尖端气膜冷却设计将基于数值模拟和现有的工业设计开发。数值研究将包括reynolds - average - navier - stokes （RANS）计算和直接数值模拟（DNS）。RANS计算将用于在实际发动机条件下对不同的叶尖和叶尖冷却配置进行分析，以确定最有希望的概念。这些有希望的概念将在实验研究中进行详细的研究。DNS计算将在较低雷诺数下进行，目的是了解潜在的流动物理，并评估和改进RANS过程中使用的湍流模型。后者是必要的，以便加强基于RANS的叶片-尖端和尖端冷却配置的评估。

ABSTRACTProposal Number: CTS 9907773Principal Investigator: S. Ekkad and S. AcharyaThis award is to support an investigation of the fundamental issues pertaining to blade tip aerodynamics and heat transfer, and to provide guidance to the gas turbine industry for improved blade-tip cooling strategies that will aid in improving blade life and reduce maintenance requirements for gas turbine engines. This is a GOALI proposal submitted jointly by Louisiana State University and General Electric Company. General Electric will be primarily responsible for the technology transfer and in testing, using industry-standard procedures, of improved designs and concepts resulting from the proposed research at LSU. The experimental study will be conducted on a five blade linear cascade with high-pressure compressed air flow facility capable of providing engine representative flow conditions. An engine typical PT,rel,inlet/PS,exit will be simulated to ensure real pressure-driven leakage flow across the tip from pressure surface to suction surface. A 2-D turbine blade cascade will be used for this study. A typical clearance gap will be set for the middle blade of the five-blade cascade. Relative motion of blade with the shroud will be simulated with a moving belt acting as the shroud. Velocity and pressure measurements will be obtained on the pressure and suction surface and the shroud and tip regions. Detailed mass/heat transfer measurements will be obtained on the pressure surface, the suction surface and the tip region using the Naphthalene sublimation technique. Two blade tip designs, plain and squealer, will be studied. Tip film cooling designs for experimental testing will be developed based on numerical simulations and existing industry designs.The numerical study will involve a combination of Reynolds-Averaged-Navier-Stokes (RANS) calculations with suitable turbulence models, and Direct Numerical Simulation (DNS). The RANS calculations will be used to perform analysis for different blade-tip and tip-cooling configurations under realistic engine conditions in order to determine the most promising concepts. These promising concepts will then be investigated in detail in the experimental study. The DNS calculations will be performed at lower Reynolds numbers with the intent of understanding the underlying flow physics, and to evaluate and improve the turbulence models being used in the RANS procedure. The latter is necessary in order to strengthen the RANS based assessment of blade-tip and tip-cooling configurations.