Abstract: Experimental investigation of 25 models that are designed according to the orthogonal table to study the influence of the geometry parameters including fin tip thickness t, seal clearance c, fin height H, fin pitch B, front fin taper angle  and back fin taper angle β on heattransfer characteristics of straight-through labyrinth seal at the same pressure ratio. The results show that there are obvious differences between the geometry parameters about the influence on convective heattransfer coefficient. In all of the parameters, the rank of importance on heattransfer characteristics is c→B→H→t→→, C and B affect heattransfer characteristics evidently, His less important t also have certain impact on heattransfer characteristics, while  and  have little influence on it. The geometry for least heat transfer in the test area is t = 0.1 mm, c =0.2 mm, H = 5 mm, B = 6 mm,  = 8°, β = 15°.

Key words: Convection heat transfer coefficient, Geometrical parameters, Leakage, Orthogonal, Straight-through labyrinth