Windage Measurements in a Rotor Stator Cavity With Rotor Mounted Protrusions and Bolts
Windage Measurements in a Rotor Stator Cavity With Rotor Mounted Protrusions and Bolts
复制标题
使用安装在转子上的突出部和螺栓的转子定子腔中的风阻测量
DOI：
10.1115/gt2012-69385
复制
发表时间：
2012
影响因子：
1.7
通讯作者：
Daniel Coren
中科院分区：
文献类型：
--
作者：
C. Long;A. Miles;Daniel Coren
本文报道了一项与燃气涡轮发动机中常见的具有叠加通流的封闭转子-定子系统相关的窗口的实验研究。在旋转圆盘系统中，由于表面和流体的相互作用而产生的粘性加热常被用来描述这个术语。由于圆周离散几何特征的存在强烈地改变了测量到的Windage的大小，本文中统称为Windage的物理机制被单独描述为结果讨论的一部分。
This paper reports an experimental investigation of the windage associated with enclosed rotor-stator systems with superposed throughflow, as commonly found in gas turbine engines. The term windage is often used to describe the viscous heating that arises from the interaction of surfaces and fluids in rotating disc systems. Since the presence of circumferentially discreet geometric features strongly alters the magnitude of Windage measured, the physical mechanisms collectively referred to as windage in this paper are separately described as part of the discussion of results.
Tests have been carried out to measure windage directly in the form of shaft torque and also rotor surface temperature. Non-dimensional flow parameters are used to expand the relevance of the data obtained, which encompasses the ranges 0.17 x 107 ≤ Reφ ≤ 1.68 x 107and 0.24 x 105 ≤ Cw ≤ 1.06 x 105 which corresponds to 0.058 ≤ λT ≤ 0.631. Data has been obtained for smooth disc geometry and also with rotor mounted protrusions of N = 3, 9 and 18; D = 10 mm, 13 mm and 16 mm diameter; H = 11 mm, high, hexagonal bolt shaped protrusions. Bi-hexagonal (twelve sided) bolts of D = 13 mm effective diameter, and height, H = 11mm, were also tested with conditions closely matched to the 13 mm hexagonal bolts. Finally, tests with 10 mm diameter, 6 mm deep, pockets were also carried out.
Over the range of conditions and geometries tested, increasing the number of bolts increases the moment coefficient and windage heating. At low values of turbulent flow parameter, λT, which correspond to rotational speeds between 8000 and 10000 rev/min, increasing the diameter of the bolts shows a clear trend for both increased windage torque and average disc temperature rise. For these conditions, there also appears to be a clear reduction in windage and temperature rise with the bi-hexagonal shaped bolts compared to the equivalent diameter hexagonal bolt form. Variation in the moment coefficient with the number and diameter of bolts is attributed to variations in form drag between the different configurations. The introduction of the recesses onto the disc has very little effect on either windage heating or moment coefficient; this is attributed to the component of windage mechanism in operation and also the relatively small size in comparison to the protrusions studied here.
This work contributes to the understanding of windage in gas turbines by introducing new low uncertainty data obtained at engine representative conditions and as such is of benefit to those involved with the design of internal air systems and disc fixtures