Effect of temperature ratio on the film cooling with the rotation
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摘要: 为了研究在旋转状态下温度比对气膜与主流掺混区域的影响,采用了数值模拟的方法对此进行了分析.结果表明:与静止状态相比,气膜出流在旋转状态下会发生偏转.当温度比固定,随着转速的增加,吸力面上气膜覆盖区域向高旋转半径方向偏转;但在压力面上,覆盖区域向低旋转半径方向偏转.在旋转速度固定时,随着冷却气膜和燃气温度比的增加,气膜覆盖区域向高旋转半径方向偏转.旋转同时会降低气膜冷却效率,而温度比对此的影响却很小.Abstract: A computional heat transfer(CHT) analysis was carried out to comprehend the mechanism of rotation and the temperature ratio of the film and the main flow on the film cooling which is important in understanding the mixing process between the film coolant and the hot stream air over the high pressure turbine blades. It was found that both parameters could affect the distribution of the film cooling, which was clearly shown with the film cooling effectiveness distribution graph. On the suction side rotation leads to that the effective film trace bends centrifugally and on the pressure side it inclines centripetally, which is consistent with the direction of the Coriolis force. With the increase of the coolant-to-mainstream temperature ratio, the effective film trace bends centrifugally, which is determined by the increase of the centrifugal buoyancy force. Rotation could lead to the decrease of the film cooling effectiveness. Contrast to this, temperature ratio has little effect on the film cooling effectiveness.
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Key words:
- rotation /
- temperature /
- numerical computation /
- buoyancy
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