In this article,we first give two simple examples to illustrate that two types of parametric representation of the family ofΣ0 K have some gaps.Then we also find that the area derivative formula(1.6),which is used to...In this article,we first give two simple examples to illustrate that two types of parametric representation of the family ofΣ0 K have some gaps.Then we also find that the area derivative formula(1.6),which is used to estimate the area distortion ofΣ0 K,cannot be derived from[6],but that formula still holds forΣ0 K through our amendatory parametric representation for the one obtained by Eremenko and Hamilton.展开更多
The purpose of the investigation is to obtain the mechanism of affecting the performance and stability of an axial flow compressor with two kinds of multi distortion area.In the investigation,the compressor inlet dist...The purpose of the investigation is to obtain the mechanism of affecting the performance and stability of an axial flow compressor with two kinds of multi distortion area.In the investigation,the compressor inlet distortion is made by the distortion generator,which is a column and is placed in the compressor rotor passage upstream.The five-passages unsteady numerical results show that the compressor performances for two kinds of multi distortion area are both lower than that for the clean inlet,and the compressor peak efficiencies for inlet distortions of 6×12 degrees and 6×24 degrees are about 3.5%,and 9.2%lower than that for the clean inlet,respectively.Further,two kinds of multi distortion area both reduce the compressor stability,and the stall margin improvements of–2.93%and–6.11%are provided by inlet distortions of 6×12 degrees and 6×24 degrees,respectively.The flow field analyses show that the flow conditions of the rotor tip inlet upstream deteriorate after the application of multi distortion area.The values of axial velocity and flow angle of incoming flows in some regions,which are near the shroud,become small due to the adverse effect made by the inlet distortion.So,the circulation capacity of the regions becomes low,and inlet blockages appear in some rotor tip passages.The bigger the distorted range is,the greater inlet blockages and corresponding flow losses are.When multi distortion area changes from 6×12 degrees to 6×24 degrees,there are obvious separations of the boundary layer near the blade suction surface in some blade tip passages,and the serious separations prevent the incoming flows from entering the blade tip passage.As a result,overflows occur at the leading edge of the blade tip.Furthermore,as the number of the distortion generator increases by a factor of one,the effects of inlet distortion on the amplitudes of the air relative velocity and static pressure in the rotor inlet upstream at the distortion generator passing frequency of 1076.5 Hz increase by a factor of about one.展开更多
基金National Natural Science Foundation of China(11971182)the Promotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University(ZQN-PY402)+1 种基金Research projects of Young and Middle-aged Teacher's Education of Fujian Province(JAT190508)Scientific research project of Quanzhou Normal University(H19009).
文摘In this article,we first give two simple examples to illustrate that two types of parametric representation of the family ofΣ0 K have some gaps.Then we also find that the area derivative formula(1.6),which is used to estimate the area distortion ofΣ0 K,cannot be derived from[6],but that formula still holds forΣ0 K through our amendatory parametric representation for the one obtained by Eremenko and Hamilton.
基金supports by National Natural Science Foundation of China with project No.51006084supported by National Science and Technology Major Project No.2017-II-0005-0018the Fundamental Research Funds for the Central Universities with project No.3102019ZX026。
文摘The purpose of the investigation is to obtain the mechanism of affecting the performance and stability of an axial flow compressor with two kinds of multi distortion area.In the investigation,the compressor inlet distortion is made by the distortion generator,which is a column and is placed in the compressor rotor passage upstream.The five-passages unsteady numerical results show that the compressor performances for two kinds of multi distortion area are both lower than that for the clean inlet,and the compressor peak efficiencies for inlet distortions of 6×12 degrees and 6×24 degrees are about 3.5%,and 9.2%lower than that for the clean inlet,respectively.Further,two kinds of multi distortion area both reduce the compressor stability,and the stall margin improvements of–2.93%and–6.11%are provided by inlet distortions of 6×12 degrees and 6×24 degrees,respectively.The flow field analyses show that the flow conditions of the rotor tip inlet upstream deteriorate after the application of multi distortion area.The values of axial velocity and flow angle of incoming flows in some regions,which are near the shroud,become small due to the adverse effect made by the inlet distortion.So,the circulation capacity of the regions becomes low,and inlet blockages appear in some rotor tip passages.The bigger the distorted range is,the greater inlet blockages and corresponding flow losses are.When multi distortion area changes from 6×12 degrees to 6×24 degrees,there are obvious separations of the boundary layer near the blade suction surface in some blade tip passages,and the serious separations prevent the incoming flows from entering the blade tip passage.As a result,overflows occur at the leading edge of the blade tip.Furthermore,as the number of the distortion generator increases by a factor of one,the effects of inlet distortion on the amplitudes of the air relative velocity and static pressure in the rotor inlet upstream at the distortion generator passing frequency of 1076.5 Hz increase by a factor of about one.
