Performance Analysis of Inter-Stage Leakage Flows at Rotating Conditions in an Axial Compressor
- PDF / 2,109,261 Bytes
- 11 Pages / 595.22 x 842 pts (A4) Page_size
- 3 Downloads / 169 Views
https://doi.org/10.1007/s11630-020-1378-z
Article ID: 1003-2169(2020)00-0000-00
Performance Analysis of Inter-Stage Leakage Flows at Rotating Conditions in an Axial Compressor KONG Xiaozhi1*, LIU Yuxin2*, LU Huawei1, TIAN Zhitao1, XIN Jianchi1 1. Naval Architecture and Ocean Engineering College, Dalian Maritime University, Dalian 116026, China 2. Marine Engineering College, Dalian Maritime University, Dalian 116026, China © Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract: For the compressor with shrouded stator blades, the stator well is a rotor-stator space between the rotating drum and the stationary shroud. Due to the pressure difference, a reverse leakage flow would travel through the stator well and inject into the main flow path. Although, the labyrinth seal is commonly placed under the shroud, the rotation effect and seal clearance variation in actual operation process have great impact on the characteristics of this inter-stage leakage, as well as the compressor performance. In this paper, experiments were conducted at a compressor inter-stage seal test rig. The leakage flow rates, total temperatures and swirl ratios were obtained at different speeds and working clearances. The proportions of rotation effect and the clearance reduction effect were analyzed by data processing. Comparisons indicate that the working clearance and leakage flow reduce about 43% and 50% respectively, when the rotational speed ω=8100 r/min. The proportion of reduction caused by the rotation effect is around 15%, while the influence of working clearance variation is much greater, accounting for about 35%. The windage heating coefficient and swirl ratio in the outlet cavity are almost in exponential relationship with the rotor speed. The increases in total temperature and swirl ratio generated by the rotation effect are found to be about 80%. In addition, the swirl and radial velocity profiles in the cavities were discussed by validated numerical simulations to reveal the typical flow characteristics. The data presented can provide guidance for better leakage conditions prediction as well as the inter-stage seal design enhancement.
Keywords: shrouded stator blade, inter-stage seal, rotor-stator cavity, leakage flow, windage heating, swirl ratio
1. Introduction In aero-engines, especially for the compressor and turbine, there are many rotor-stator gaps or cavities between stationary and rotating components. The unwanted leakage will be occurred in these places, which can lead to lower engine efficiency [1]. In addition, the total temperature increase of the leakage flow induced by Received: May 07, 2020 AE: DU Juan
the windage heating can further affect the engine thermal balance and lifetime. Therefore, seals employed in the aero-engine to control the leakage flow are crucial to maintain the necessary aerodynamic and thermodynamic operating conditions [2]. For the compressor with shrouded stator blades, the typical inter-stage space, the so-called
Data Loading...
