In this paper, the research work on aeroacoustics in turbomachinery done in the Thermoturbomachinery institute, Department of Power Machinery Engineering, Shanghai Jiao Tong University, for the past 15 years is summar...In this paper, the research work on aeroacoustics in turbomachinery done in the Thermoturbomachinery institute, Department of Power Machinery Engineering, Shanghai Jiao Tong University, for the past 15 years is summarized. It includes: aeroacoustic similarity law and correction ofnon--similarity) mechanism of acoustic control of separated flow, aerodynamic and aeroacoustic comprehensive optimum calculation, and the influence of inlet turbulence and inlet distortion.展开更多
The present contribution describes two prediction methods for flows around transonic airfoils, including shock control devices. The wliole work was done in the frame of the European Shock Control Inves tigation Projec...The present contribution describes two prediction methods for flows around transonic airfoils, including shock control devices. The wliole work was done in the frame of the European Shock Control Inves tigation Project EUROSHOCK-AER-2, and the global objective was the improvement of the flight performance, in transonic speed, in terms of cruise speed, fuel consumption and exhaust emissions for both laminar and turbulent wings. More specilically the "passive" control of shock/boundary layer interaction, whereby part of the solid suLrfaCe of the airfoil is replaced by a porous surface over a shallow cavity, has been shown to be a means of improving the aerodynamic characteristics of supercritical airfoils.展开更多
Control of supersonic flow fields with shock wave is important for some industrial fields. There are many studies for control of the supersonic flow fields using active or passive control. When non-equilibrium condens...Control of supersonic flow fields with shock wave is important for some industrial fields. There are many studies for control of the supersonic flow fields using active or passive control. When non-equilibrium condensation occurs in a supersonic flow field, the flow is affected by latent heat released. Many studies for the condensation have been conducted and the characteristics have been almost clarified. Further, it was found that non-equilibrium condensation can control the flow field. In these studies, the condensation occurs across the passage of the flow field and it causes the total pressure loss in the flow field. However, local occurrence of non-equilibrium condensation in the flow field may change the characteristics of total pressure loss compared with that by the condensation across the passage of the nozzle and there are few for researches of locally occurred non-equilibrium condensation in supersonic flow field. The purpose in the present study is to clarify the effect of local occurrence of non-equilibrium condensation on the transonic flow field in a nozzle with a circular bump. As a result, local occurrence of non-equilibrium condensation reduced the shock strength and total pressure loss in the transonic flow field by flowing the moist air from trailing edge of the circular bump to the mainstream.展开更多
The application of an efficient flow control system on helicopter rotor blades may lead to improved aerodynamic performance. Recently, our invention of Rod Vortex Generators(RVGs) has been analyzed for helicopter roto...The application of an efficient flow control system on helicopter rotor blades may lead to improved aerodynamic performance. Recently, our invention of Rod Vortex Generators(RVGs) has been analyzed for helicopter rotor blades in hover with success. As a step forward, the study has been extended to forward flight conditions. For this reason, a validation of the numerical modelling for a reference helicopter rotor(without flow control) is needed. The article presents a study of the flow-field of the AH-1G helicopter rotor in low-, medium- and high-speed forward flight. The CFD code FLOWer from DLR has proven to be a suitable tool for the aerodynamic analysis of the two-bladed rotor without any artificial wake modelling. It solves the URANS equations with LEA(Linear Explicit Algebraic stress) k-ω model using the chimera overlapping grids technique. Validation of the numerical model uses comparison with the detailed flight test data gathered by Cross J. L. and Watts M. E. during the Tip Aerodynamics and Acoustics Test(TAAT) conducted at NASA in 1981. Satisfactory agreements for all speed regimes and a presence of significant flow separation in high-speed forward flight suggest a possible benefit from the future implementation of RVGs. The numerical results based on the URANS approach are presented not only for a popular, low-speed case commonly used in rotorcraft community for CFD codes validation but preferably for medium- and high-speed test conditions that have not been published to date.展开更多
文摘In this paper, the research work on aeroacoustics in turbomachinery done in the Thermoturbomachinery institute, Department of Power Machinery Engineering, Shanghai Jiao Tong University, for the past 15 years is summarized. It includes: aeroacoustic similarity law and correction ofnon--similarity) mechanism of acoustic control of separated flow, aerodynamic and aeroacoustic comprehensive optimum calculation, and the influence of inlet turbulence and inlet distortion.
文摘The present contribution describes two prediction methods for flows around transonic airfoils, including shock control devices. The wliole work was done in the frame of the European Shock Control Inves tigation Project EUROSHOCK-AER-2, and the global objective was the improvement of the flight performance, in transonic speed, in terms of cruise speed, fuel consumption and exhaust emissions for both laminar and turbulent wings. More specilically the "passive" control of shock/boundary layer interaction, whereby part of the solid suLrfaCe of the airfoil is replaced by a porous surface over a shallow cavity, has been shown to be a means of improving the aerodynamic characteristics of supercritical airfoils.
文摘Control of supersonic flow fields with shock wave is important for some industrial fields. There are many studies for control of the supersonic flow fields using active or passive control. When non-equilibrium condensation occurs in a supersonic flow field, the flow is affected by latent heat released. Many studies for the condensation have been conducted and the characteristics have been almost clarified. Further, it was found that non-equilibrium condensation can control the flow field. In these studies, the condensation occurs across the passage of the flow field and it causes the total pressure loss in the flow field. However, local occurrence of non-equilibrium condensation in the flow field may change the characteristics of total pressure loss compared with that by the condensation across the passage of the nozzle and there are few for researches of locally occurred non-equilibrium condensation in supersonic flow field. The purpose in the present study is to clarify the effect of local occurrence of non-equilibrium condensation on the transonic flow field in a nozzle with a circular bump. As a result, local occurrence of non-equilibrium condensation reduced the shock strength and total pressure loss in the transonic flow field by flowing the moist air from trailing edge of the circular bump to the mainstream.
基金supported by the 7th Framework Programme project IMESCON(PITN-GA-2010-264672)and in part by PL-Grid Infrastructure
文摘The application of an efficient flow control system on helicopter rotor blades may lead to improved aerodynamic performance. Recently, our invention of Rod Vortex Generators(RVGs) has been analyzed for helicopter rotor blades in hover with success. As a step forward, the study has been extended to forward flight conditions. For this reason, a validation of the numerical modelling for a reference helicopter rotor(without flow control) is needed. The article presents a study of the flow-field of the AH-1G helicopter rotor in low-, medium- and high-speed forward flight. The CFD code FLOWer from DLR has proven to be a suitable tool for the aerodynamic analysis of the two-bladed rotor without any artificial wake modelling. It solves the URANS equations with LEA(Linear Explicit Algebraic stress) k-ω model using the chimera overlapping grids technique. Validation of the numerical model uses comparison with the detailed flight test data gathered by Cross J. L. and Watts M. E. during the Tip Aerodynamics and Acoustics Test(TAAT) conducted at NASA in 1981. Satisfactory agreements for all speed regimes and a presence of significant flow separation in high-speed forward flight suggest a possible benefit from the future implementation of RVGs. The numerical results based on the URANS approach are presented not only for a popular, low-speed case commonly used in rotorcraft community for CFD codes validation but preferably for medium- and high-speed test conditions that have not been published to date.
