Time-Resolved Heat Transfer Measurements on the Tip Wall of a Ribbed Channel Using a Novel Heat Flux Sensor-Part II: Heat Transfer Results
Time-Resolved Heat Transfer Measurements on the Tip Wall of a Ribbed Channel Using a Novel Heat Flux Sensor-Part II: Heat Transfer Results
复制标题
使用新型热通量传感器对带肋通道的尖端壁进行时间分辨传热测量 - 第二部分：传热结果
DOI：
10.1115/1.2472417
复制
发表时间：
2008
影响因子：
1.7
通讯作者：
E. Kraemer
中科院分区：
文献类型：
--
作者：
S. Jenkins;J. Wolfersdorf;B. Weigand;T. Roediger;H. Knauss;E. Kraemer
采用一种新型热流密度传感器，在一个代表燃气轮机叶片内部冷却通道的内部肋形通道中进行了测量。这些测量允许表征传热湍流水平和不稳定性，而不是以前可用于内部冷却通道。在传热研究中，为了理解系统中的热负荷，波动通常与平均值一样重要。在这项研究中，比较了使用该传感器获得的时间平均值和使用瞬态热液晶技术进行的详细表面测量。时间平均热通量传感器和瞬态薄层色谱结果吻合良好，验证了两种方法的有效性。时间分辨的测量结果也与传感器所在位置壁面的热膜测量结果相印证，以更好地阐明壁面速度场的非定常对热流通量波动的影响。这些测量结果的湍流强度的速度和热通量的20%。流速和热流积分长度分别约为通道宽度的60%和35%，导致壁面湍流普朗特数为1.7。
Measurements using a novel heat flux sensor were performed in an internal ribbed channel representing the internal cooling passages of a gas turbine blade. These measurements allowed for the characterization of heat transfer turbulence levels and unsteadiness not previously available for internal cooling channels. In the study of heat transfer, often the fluctuations can be equally as important as the mean values for understanding the heat loads in a system. In this study, comparisons are made between the time-averaged values obtained using this sensor and detailed surface measurements using the transient thermal liquid crystal technique. The time-averaged heat flux sensor and transient TLC results showed very good agreement, validating both methods. Time-resolved measurements were also corroborated with hot film measurements at the wall at the location of the sensor to better clarify the influence of unsteadiness in the velocity field at the wall on fluctuations in the heat flux. These measurements resulted in turbulence intensities of the velocity and heat flux of 20%. The velocity and heat flux integral length scales were about 60% and 35% of the channel width, respectively, resulting in a turbulent Prandtl number of 1.7 at the wall.