Abstract
Unsteady and quasi-steady steady numerical simulation were carried out to investigate the film cooling characteristics of the unsteady film cooling performance, for mainstream with periodic pressure fluctuations. The results shows that: compared with the pressure fluctuations in mainstream area, gas film hole outlet influenced by the pressure at previous point in time, which results in the pressure fluctuation delay characteristics; For the waveform studied in this paper, the pressure fluctuation delay leads to pressure difference (between secondary flow and the mainstream) can not affect the secondary flow quickly and directly on the one hand, which prevents backflow and won more stable mass flow rate of secondary flow; On the other hand, the pressure fluctuation carries such outward rotation of the vortex in the circumferential direction which close to the casing surface outlet of the film cooling holes. The vortices bring secondary flow which has ejected back to the wall, so that the secondary flow is close to the casing surface. For mainstream characteristic of a particular periodic pressure fluctuations condition, it is present in the best design so that mass flow stability of the film cooling hole and preventing backflow characteristics are also the best. This paper bring the study of film cooling turbine film cooling holes under periodic pressure fluctuations a greater significance.
| Original language | English |
|---|---|
| Pages (from-to) | 209-214 |
| Number of pages | 6 |
| Journal | Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics |
| Volume | 41 |
| Issue number | 1 |
| State | Published - 1 Jan 2020 |
| Externally published | Yes |
Keywords
- Film cooling
- Preventing backflow characteristics
- Turbine casing
- Unsteady numerical simulation