EXPERIMENTAL INVESTIGATION OF FISH SCALE PATTERNED CASCADE

Several cascades with different patterns have been tested with the purpose of turbulence drag reduction in compressor cascade,after the straight patterned cascade obtained notable effects.The fish scale patterned cascade is the best of them.The main performance comparison is shown as follows: CascadeMa1cr△βdesignδdesign(P2/P1)2Dmaxξi=05°/%△ireference straight pattern fish scale pattern0685 0735 0750408° 417° 411°67° 58° 64°11810 11987 1212757609 34261 30610100° 104° 104° The above test data indicate that most of performance indices of the fish scale patterned cascade,such as critical Mach number Ma1cr,maximum two-dimensional static compression ratio (P2/P1)2Dmax and total pressure loss coefficient at maximum attack angle ξi=05° are improved over the straight patterned cascade.The other performance parameters,namely attack angle range △i,flow deflection angle at design point △βdesign and corresponding deviation angle at design point δdesign,are superior to the reference cascade as well.It is particularly worth to point out that the fish scale pattern and the straight pattern can be together applied to the same blade to obtain advantageous performance.