An Investigation Of Performance By Using Blade Tip Winglet In Rectangular Compressor Cascade

With the rapid development of the aviation industry, the performance of aero-engine develop towards improving the thrust-weight ratio, reducing the specific fuel consumption, improving the efficiency and safety. And as one of the core component of an aircraft engine, compressor mainly calls for the higher total pressure ratio and efficiency and the greater level of load. Among them, ascending the load will add the leakage from blade tip and cause the separation easier. Numerous studies have shown that, the energy loss by blade tip leakage occupies a pivotal position in total loss. Reducing the blade tip leakage will improve the aerodynamic performance of the compressor; therefore, effectively restraining the compressor blade tip leakage flow becomes one of the important research directions for experts at home and abroad.Being inspired by the winglet of an aircraft, improving the cascade aerodynamic performance by using blade tip winglet in compressor blade is the main research contents of this paper.This paper, by measuring the blowback low speed wind tunnel experiments the pneumatic parameters of the original blade (i.e. blade without tip winglet), the blade with suction side tip winglet, the blade with pressure side tip winglet and the blade with a combination side tip winglet (that is, with both the suction side and the pressure side tip winglet) at the exist section of the blade passage which is under different clearance and different incidence angle. Meanwhile, the wall static pressure distribution is measured. The aim of this experiment is to study the influence on improving the pneumatic performance by application of blade tip winglet in the rectangular compressor cascade and its mechanism. Compared with the original blade, the blade with suction side tip winglet effectively weakens the scale and intensity of the vortex of the blade tip leakage, so that it reduces the total energy loss of the rectangular compressor cascade, and effectively improves the aerodynamic performance of the cascade. The experimental results show that in the zero incidence angle and the blade tip clearance for 1.0%H (that is, the blade tip clearance for 1% blade height) conditions, the blade with suction side tip winglet improves the aerodynamic performance obviously. And the blade with pressure side tip winglet increases the strength of the blade tip leakage vortex, and increases the energy losses of the cascade, so that it deteriorates the pneumatic performance of the cascade.Under the influence of the blade with section side tip winglet and pressure side tip winglet, the blade with combination tip winglet does not play an obviously part in aerodynamic influence.Under different incidence angles, the energy losses of original blade fluctuation relatively intense, and the energy losses of blade with suction side tip winglet change smoothly. The blade with suction side tip winglet on one hand reduces the energy losses of cascade, and improves the efficiency of the cascade. On the other hand, it makes blade attack Angle characteristics changing more smoothly. The experiment study found that under a large negative incidence angle, the blade with pressure side tip winglet and combination tip winglet not only reduce the energy losses of cascade, but sharpen the blade pressure surface separation degree.This paper, numerical simulates the vortex structure of the original blade and the blade with suction side tip winglet under 0°incidence angle, and the blade tip clearance for 1.0%H. And then, the three-dimensional vortex structure is establishes. Meanwhile, the development and the law of blade tip leakage vortex, passage vortex, and concentrated shed vortex are analyzed. From the perspective of the vortex structure evolution, this paper analyses the effect mechanism about blade with tip winglet to the rectangular compressor cascade.