Flow and heat transfer in gas turbine disk cavities subject to nonuniform external pressure field
- Arizona State Univ., Tempe, AZ (United States)
Injestion of hot gas from the main-stream gas path into turbine disk cavities, particularly the first-stage disk cavity, has become a serious concern for the next-generation industrial gas turbines featuring high rotor inlet temperature. Fluid temperature in the cavities increases further due to windage generated by fluid drag at the rotating and stationary surfaces. The resulting problem of rotor disk heat-up is exacerbated by the high disk rim temperature due to adverse (relatively flat) temperature profile of the mainstream gas in the annular flow passage of the turbine. A designer is concerned about the level of stresses in the turbine rotor disk and its durability, both of which are affected significantly by the disk temperature distribution. This distribution also plays a major role in the radial position of the blade tip and thus, in establishing the clearance between the tip and the shroud. To counteract mainstream gas ingestion as well as to cool the rotor and the stator disks, it is necessary to inject cooling air (bled from the compressor discharge) into the wheel space. Since this bleeding of compressor air imposes a penalty on the engine cycle performance, the designers of disk cavity cooling and sealing systems need to accomplish these tasks with the minimum possible amount of bleed air without risking disk failure. This requires detailed knowledge of the flow characteristics and convective heat transfer in the cavity. The flow in the wheel space between the rotor and stator disks is quite complex. It is usually turbulent and contains recirculation regions. Instabilities such as vortices oscillating in space have been observed in the flow. It becomes necessary to obtain both a qualitative understanding of the general pattern of the fluid motion as well as a quantitative map of the velocity and pressure fields.
- Research Organization:
- USDOE Morgantown Energy Technology Center (METC), WV (United States); USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States). Office of Industrial Technologies
- OSTI ID:
- 269474
- Report Number(s):
- DOE/METC-96/1023-Vol.2; CONF-9510109-Vol.2; ON: DE96000562; TRN: 96:002470-0025
- Resource Relation:
- Conference: Advanced turbine systems (ATS) annual review, Morgantown, WV (United States), 17-18 Oct 1995; Other Information: PBD: Oct 1995; Related Information: Is Part Of Proceedings of the Advanced Turbine Systems Annual Program Review meeting. Volume 2; PB: 412 p.
- Country of Publication:
- United States
- Language:
- English
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