Abstract: The geometric feature of the arc finger seal is analysed. The relationship between the finger stick arc radius and the stick arc center circle radii and their value scope are determined too. The integrative capability optimization method of finger seals with the objectives of low leakage and low wear function is established. An optimization example indicated that it is possible to obtain an arc finger seal structure with good integration performance in certain conditions. By analysing the sensitivity of design variables, it is discovered that the varables affecting the performance of the seal include in decreasing order, the stick arc radius, the finger repeat angle, the height of the finger foot, the height between the back plate and rotor surface and the thickness of the seal. Compared with the involute finger seal, the arc finger seal has the advantage of low leakage. The work provides a basis for further study on the arc finger seal to obtain better structure in different conditions.

Key words: arc finger seal, leakage rate, wear rate, integrative capability optimization, sensitivity analysis