后挡板结构对刷式密封泄漏特性影响实验研究

Experimental Investigation for Effects of Back Plate Structure on Leakage Characteristics of Brush Seal

关键词:  航空发动机  泄漏特性  刷式密封  密封性能  试验研究

Key words:  Aeroengine  Leakage characteristics  Brush seal  Sealing characteristics  Experiment investigation

摘要:

为了研究后挡板结构对刷式密封泄漏特性的影响，模拟航空发动机静态和动态工况，对三种不同后挡板结构的刷式密封泄漏特性进行实验研究。实验结果表明：相比于标准型刷式密封，后挡板结构中设计环形平衡腔能有效缓解刷式密封刷丝滞后效应，但间隙值过大将导致刷式密封性能下降；刷式密封实验件b（有环形平衡腔，与刷丝束之间的间隙为0.2mm）的泄漏参数Φ₂保持在7g·K·mm/（N·s）以内，表现出优异的密封性能，这说明合适的环形平衡腔间隙值设计，能有效缓解刷式密封刷丝滞后现象。根据实验结果，环形平衡腔的间隙设计值应不大于0.4mm。

Abstract:

To study the effects of back plate structure on leakage characterics of brush seal， an experimental investigation on leakage characteristics of brush seal with three different back plate structures was carried， which simulated the static and dynamic working conditions of a specific areoengine. The experimental results showed that the back plate structure with a relief annulus could better alleviate the hysteresis of brush seal than the standard brush seal， but the excessive size of relief annulus gap would lead to the performance degradation of brush seal. The leakage parameter of brush seal b （with a relief annulus gap of 0.2mm from the bristle pack） Φ₂ were kept within 7g·K·mm/（N·s） and it showed excellent sealing performance. The results also showed that hysteresis effect of bristle pack could be effectively alleviated by designing reasonable relief annulus gap. According to the experimental results， the relief annulus gap should be no more than 0.4mm.