Stators Design For Highly Loaded Aspirated Low Reaction Compressor

Aeroengine is the core of aeroplane whose design level as long as manufactureand related industries represent the highest industry level of a country thus is calledthe crown of industry. The need to improve thrust-weight ratio and efficiency leadto a challenge for the compressor to give a higher total pressure ratio, higherefficiency, shorter axial length and lower weight. This levels up the design of thecompressor.Song Tao.W from Harbin Institute of Technology firstly put up the designmethod of high loaded low reaction aspirated compressor which ensures effectiveflow in the rotor and diffusion in the stator through boundary layer suction in thestator such that avoiding boundary layer suction in rotor. Taking advantage of themethod, a three stages highly loaded low reaction aspirated compressor wasdesigned whose efficiency is88.2%with a suction of11.2%. This compressor madea new way on the design concept of compressor although as it is always in thedevelopment of things there are still areas to be explored.This paper takes the three stages compressor as media to undertake a researchon details in the stator design progress and makes a basic contribution for the designmethod of highly loaded low reaction aspirated compressor. It is primarilyconducted for the purpose of improving throttling range, reducing the suction andimproving compressor efficiency.Firstly different sweep blade was applied to the first stage stator which is ultrasonic aspirated stator to explore the effort of sweeping blade. Forward sweep,backward sweep and sweep through changing chord length were carried out.Comparison of different sweep angle cases showed that sweep both forward andbackward decreases throttling range and changes the shock positions. Shockposition has an impact on the boundary layer development and thus changes thesuction.It is common sense that the slot in the blade will weaken blade strength andthis will lead a disaster damage to aeroengine. So low aspect ratio which has athicker blade is beneficial for highly loaded low reaction aspirated compressor’strength. This leads to a research on the effect of changing aspect ratio to highly loaded low reaction aspirated compressor which including an ultra sonic aspiratedstator(first stator), subsonic stator(second stator), subsonic aspirated stator(thirdstator). Results showed in subsonic stators with the aspect ratio increasing cornerstall reduces in size, flow deflection increases, end wall flow deflection decreases.In ultra sonic stators, there are no explicit relations between losses and aspect ratio.It is maybe the reason that shock loss is dominant.In order to reduce suction, it is necessary to investigate the effect of suctionslots position on suction in ultra sonic aspirated stators. Different end wall slotsposition was applied to the first stator. Results dedicated that corner stall isoriginated from low energy fluid stagnation and backflow under the negativepressure gradient and wall friction. The off set of end wall slots from corner regionto the middle region of passage weakens the effect of suction on corner low energyfluid and leads to corner stall.Finally on the purposes of intensifying flow in the corner and considering thereality in engineering research on the stator fillets’ effect on aerodynamic of statorand describes the mechanism of stator fillet. It indicated that stator fillet improvesaerodynamic performance, reduces loss and improves throttling range.