考虑间隙变化的旋转篦齿流动特性实验

Experiment on flow characteristic in rotating labyrinth with consideration of clearance change

对台阶型封严篦齿流动特性进行了实验研究。考虑齿顶间隙变化,研究了不同压比(1.1~1.6),不同转速(0~8 100r/min)对篦齿泄漏流量、流量系数、风阻温升的影响。通过测量转盘和静止机匣的径向变形来获得篦齿工作间隙。利用插值法保证间隙一定,研究了转速这一个单一变量对篦齿封严流动特性的影响。结果表明:随着压比增大,泄漏流量增大,流量系数增大,小压比(压比为1.3)时增长较快,齿顶间隙微弱降低,风阻温升减小。随着转速的增加,泄漏流量和流量系数降低,齿顶间隙减小,风阻温升增大。间隙一定时,转速增加有利于提高篦齿密封特性。

Experimental investigation on the flow characteristics of the stepped labyrinth seal was carried out.The effects of rotational speeds（0-8 100 r/min）on the leakage flow,discharge coefficient,variation of tip clearance,windage heating characteristics were studied at different pressure ratios（1.1-1.6）.Tooth tip clearance can be acquired in accuracy,when the radial deformation of static crankcase and rotating disk was monitored by laser distance sensor.Application of interpolation method was used to keep the tip clearance constant for the research on the effect of rotation on labyrinth seal performance.Results showed that with the increase of pressure ratio,the leakage flow and discharge coefficient increased,or increased faster at the low pressure ratio（pressure ratio of 1.3）.In addition,the tip clearance and windage heating decreased but the former had a small variation.With the increase of rotation speed,the leakage flow,discharge coefficient and tip clearance decreased,while the windage heating increased.Moreover,the increase of rotation speed was helpful to improve the labyrinth seal performance at the constant seal clearance.