Optimization Of Highly Loaded Aspirated Compressor Profiles

Based on the established traditional optimization design tool, an optimization design tool for axialaspirated compressor profiles is accomplished by simplifying the suction hole into a part of thesuction surface and prescribing the uniform flow flux at the suction boundary when the flow issubsonic. The optimization design tool is a mixture of a genetic algorithm, a two-dimensionalNavier-Stokes solver and a profile parameterization method, which is based on adding smoothperturbations to the original profile created by the mean line and the thickness distribution.An optimization aimed to higher diffusion factor and lower total pressure loss coefficient isprocessed, obtaining a profile with total pressure loss coefficient of0.0195and diffusion factor of0.676by suction mass flow of1%of inlet mass flow. Compared to the original profile, total pressureloss coefficient is lowed by54%and diffusion factor is kept the same. One notable feature of theoptimum profile is the inflection point at the back part of pressure surface, which contributes to thelow loss and the negative aft loading. Another optimization is processed to design the profile suitablefor the prescribed boundary conditions, and results show that the designed profile is very close to theprofile needed.By numeric method, the effect of suction parameters, including suction hole angle, suction holemodel, suction mass flow, suction location and suction hole width, on aerodynamic performance ofone of the designed cascades is analyzed, and results are concluded as follows: First, suction holeangle will influence suction mass flow needed to obtain the same cascade performance. The more theangle is, the less the mass flow is. Second, the simplified suction model obtains the same results as therelatively real suction model with suction hole angle of90degree. Third, the research on the influenceof suction mass flow reaches results that have been reached, that is, for every suction location the bestsuction mass flow exists. If suction mass flow is less than the best value, the performance is highlyinfluenced and if suction mass flow is more than the best value, the suction flow cannot be justified.Finally, when suction mass flow, suction location and suction hole width are near the design values,the cascade researched is influenced by suction location or suction hole width at neglected degrees.