Research On The Heat Transfer Characteristics Of Labyrinth Seals Based On Orthogonal Method

Labyrinth seals are a simple traditional non-contact structure with reliable performance. But there are many impact factors of the flow and heat transfer characteristics, such as the labyrinth structure and geometric parameters, speed, import and export compression ratio, the air temperature and pressure. From the literature analysis, the speed had no significant effect on leakage characteristics, especially in the case of a small speed. Generally, the labyrinth seal gap width c is much smaller than the rotating radius r. And a small arc of a circular flow can be approximated as a rectangular channel. Then the leakage characteristics are close with small difference. So we can easily adjust the gap width without replacing the test pieces, significantly reducing the costs and cycle of the tests. Thus, in order to get the basic rules of design criteria and the corresponding relationship on the flow and heat transfer characteristics of single influencing factors of the labyrinth seals in aero-engine, and finally populate the database for the labyrinth seal data, in the course of this study carried out for different factors research can be divided into two parts: Firstly, two-dimensional stationary heat transfer test rig were designed to experiment the influence on the law of rig geometry parameters; Secondly, the rim seals were researched on the effect of speed and size of wind resistance.For the study, two-dimensional heat transfer test rig developed a scheme of research program in reasonable use of orthogonal. After 25 representative experiments were drawn from the 15,625 tests, 25 test pieces were designed. Under the guidance of the similarity theory and the use of numerical simulation method, we completed the test size of the concrete structure design. Then drawing the drawings, manufacturing, assembly testing, is to ensure the accuracy of the test bed. Thus it ensured the veracity and trustiness of test results. During the experiment to measure the various parameters, a series of experimental data obtained. A method with the combination of test and numerical was developed. And after they were carried out by orthogonal test results post-processing, a set of methods for the optimization of seal structure is summed up. Then we obtained an empirical formula under experimental conditions about the leakage and heat transfer characteristics by least squares. It will provide guidance and basis for the design of labyrinth seals in the future.For rim seals, we carried out the leakage and heat transfer characteristics from the numerical calculation. The flow field and temperature field were obtained. And we have received the leakage and heat transfer characteristics of the influencing laws of speed. Especially for the model c, we have simulated the effect of the wind resistance of the secondary flow. Drag coefficient with the variation of speed was obtained.