论文部分内容阅读
针对叶尖间隙主动控制系统的高压涡轮多层机匣,研究了机匣内部斜向冲击高肋结构中,定位螺栓对机匣换热特性的影响规律。试验中改变孔平均雷诺数-Re(2543~7121)、螺栓直径与冲击孔直径比D d(2.67,4.13,5.33)、螺栓间距与冲击孔直径比S d(23.2,30.7,45.2)等参数,获得了不同工况下螺栓安装面局部和平均Nu数变化规律,并整理出对应的经验关系式。研究中发现,安装螺栓的存在,显著增强了机匣表面的局部换热效果,但是平均换热系数的提升幅度有限。研究结果表明,在本文试验参数范围内,当保持螺栓间距比不变时,增加螺栓直径可以有效强化机匣表面的换热系数,如当螺栓直径比D d由2.67增加到5.33时,螺栓周围机匣表面平均Nu数增加幅度达20%~30%。当螺栓直径比保持不变的工况中,螺栓间距比S d为30.7时机匣表面平均Nu数达到最大值,但是螺栓间距比参数对机匣表面换热系数影响相对较小,平均Nu数的变化幅度在10%以内。
Aiming at the high-pressure turbine multi-layer casing with active control system of tip clearance, the influence law of the bolt on the heat transfer characteristics of the casing is studied. The average Reynolds number-Re (2543-7121), the ratio of bolt diameter to impact hole diameter D d (2.67, 4.13, 5.33) and the ratio of bolt spacing to impact hole diameter S d (23.2, 30.7, 45.2) , The variation rules of local and average Nu number of bolt installation surface under different conditions were obtained, and the corresponding empirical relationship was concluded. The study found that the presence of mounting bolts significantly enhances the local heat transfer effect on the casing surface, but the improvement of the average heat transfer coefficient is limited. The results show that increasing the bolt diameter can effectively enhance the heat transfer coefficient on the casing surface when the bolt pitch ratio is maintained within the range of the experimental parameters. For example, when the bolt diameter ratio D d increases from 2.67 to 5.33, The average surface of the casing Nu number increased by 20% to 30%. When the bolt diameter ratio remains unchanged, the average Nu number of the casing surface reaches the maximum when the bolt spacing ratio S d is 30.7, but the influence of the bolt spacing on the heat transfer coefficient on the casing surface is relatively smaller than the average Nu number Change within 10%.