Global pressure distribution on the suction surface of a single vane in a transonic cascade wind tunnel is measured with the help of intensity-based pressure-sensitive paint (PSP) technique using a type of temperature...Global pressure distribution on the suction surface of a single vane in a transonic cascade wind tunnel is measured with the help of intensity-based pressure-sensitive paint (PSP) technique using a type of temperature-insensitive fluorescent paint and a self-made measurement system. This measurement is conducted at the outlet of the cascade wind tunnel at the Mach numbers 0.3 and 0.4, attack angle about –20°, ambient pressure 95.4 kPa and temperature 15 °C. The vane under study owns a large camber angle of ...展开更多
Experiments were carried out to study the effects of compound angle,hole arrangement,and blowing ratio on the film cooling performance of multiple rows of holes on the suction surface of a turbine blade.The turbine wo...Experiments were carried out to study the effects of compound angle,hole arrangement,and blowing ratio on the film cooling performance of multiple rows of holes on the suction surface of a turbine blade.The turbine worked at rotational speed of 600 rpm corresponding to the rotational Reynolds number of 5.36105.Three rows of cylindrical holes arranged in line or in stagger were drilled on the rotor blade suction surface at the streamwise location of 12.4%,17.8%,and 23.2%,respectively.Three compound angles,with the same streamwise angle of 45but different lateral deflection angles of 45,0,and45,were studied.The film cooling effectiveness was obtained using pressure sensitive paint(PSP)technique with average blowing ratios varied from 0.5 to 2.0.The results showed that the application of compound angle changes the jet direction in the near-hole region and makes the film spread laterally.Compared with the film cooling without compound angle,using positive and negative compound angle can improve overall average film cooling effectiveness by about 20%and 25%,respectively.The effects of the secondary flow also can be weakened.A stagger film trajectory arrangement can achieve more uniform film coverage with higher overall film cooling effectiveness.The film trajectory arrangement of a positive compound angle injection is determined by the combined effect of hole arrangement and blowing ratio.While,the film trajectory arrangement of a negative compound angle injection is almost the same as the hole arrangement and nearly does not change with the blowing ratio.展开更多
A vorticity-velocity method was used to study the incompressible viscous fluid flow around a circular cylinder with surface suction or blowing. The resulted high order implicit difference equations were effeciently so...A vorticity-velocity method was used to study the incompressible viscous fluid flow around a circular cylinder with surface suction or blowing. The resulted high order implicit difference equations were effeciently solved by the modified incomplete LU decomposition conjugate gradient scheme ( MILU-CG). The effects of surface suction or blowing' s position and strength on the vortex structures in the cylinder wake, as well as on the drag and lift forces at Reynoldes number Re = 100 were investigated numerically. The results show that the suction on the shoulder of the cylinder or the blowing on the rear of the cylinder can effeciently suppress the asymmetry of the vortex wake in the transverse direction and greatly reduce the lift force; the suction on the shoulder of the cylinder, when its strength is properly chosen, can reduce the drag force significantly, too.展开更多
This work is concerned with Magnetohydrodynamic viscous flow due to a shrinking sheet in the presence of suction. The cases of two dimensional and axisymmetric shrinking are discussed. The governing boundary layer equ...This work is concerned with Magnetohydrodynamic viscous flow due to a shrinking sheet in the presence of suction. The cases of two dimensional and axisymmetric shrinking are discussed. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are numerically solved by using an advanced numeric technique. Favorability comparisons with previously published work are presented. Numerical results for the dimensionless velocity, temperature and concentration profiles as well as for the skin friction, heat and mass transfer and deposition rate are obtained and displayed graphically for pertinent parameters to show interesting aspects of the solution.展开更多
The interaction between the cooling film on the suction surface of the transonic turbine cascade and the shock wave in the passage is analyzed by numerical calculation method.The effects of cooling pressure and incide...The interaction between the cooling film on the suction surface of the transonic turbine cascade and the shock wave in the passage is analyzed by numerical calculation method.The effects of cooling pressure and incident angle on the shock wave shape and the film cooling efficiency under the action of shock wave are studied.The results show that with the increase of exit Mach number,the incident position of the left shock wave at the trailing edge of the cascade moves backward relative to the leading edge of the adjacent cascade,and the shock wave intensity increases;there is a temperature jump behind the temperature peak at the exit Mach number of 1.05 and 1.2,the main reason is that with the increase of shock wave intensity,the interaction between shock wave and boundary layer intensifies,and the boundary layer appears local separation,in the separation region,the mixing of high-temperature mainstream and boundary layer flow intensifies,which makes the temperature in the separation region of suction surface increase;the results show that different cooling gas injection positions have great influence on the shock wave shape in the channel,and the cooling area of the wall is smaller than that before and after the shock wave,which is mainly due to the reduction of the film coverage area under the impact of the incident shock wave,after the impact zone of shock wave,the cooling film is compressed by the main stream and attached to the wall again,resulting in the discontinuous film coverage at the shock wave incident point;the film cooling efficiency decreases significantly with the increase of cooling flow angle from 25°to 35°and changes little with the increase of cooling flow angle from 35°to 45°;the cooling efficiency does not increase infinitely with the increase of blowing ratio,when the blowing ratio is greater than a certain value,the influence of blowing ratio on cooling efficiency gradually decreases.展开更多
基金National Natural Science Foundation of China (50476071, 10577020)
文摘Global pressure distribution on the suction surface of a single vane in a transonic cascade wind tunnel is measured with the help of intensity-based pressure-sensitive paint (PSP) technique using a type of temperature-insensitive fluorescent paint and a self-made measurement system. This measurement is conducted at the outlet of the cascade wind tunnel at the Mach numbers 0.3 and 0.4, attack angle about –20°, ambient pressure 95.4 kPa and temperature 15 °C. The vane under study owns a large camber angle of ...
基金the National Natural Science Foundation of China(No.51906008,No.51822602)the Fundamental Research Funds for the Central Universities(No.YWF-19-BJ-J-293)National Science and Technology Major Project(2017-III-0003-0027).
文摘Experiments were carried out to study the effects of compound angle,hole arrangement,and blowing ratio on the film cooling performance of multiple rows of holes on the suction surface of a turbine blade.The turbine worked at rotational speed of 600 rpm corresponding to the rotational Reynolds number of 5.36105.Three rows of cylindrical holes arranged in line or in stagger were drilled on the rotor blade suction surface at the streamwise location of 12.4%,17.8%,and 23.2%,respectively.Three compound angles,with the same streamwise angle of 45but different lateral deflection angles of 45,0,and45,were studied.The film cooling effectiveness was obtained using pressure sensitive paint(PSP)technique with average blowing ratios varied from 0.5 to 2.0.The results showed that the application of compound angle changes the jet direction in the near-hole region and makes the film spread laterally.Compared with the film cooling without compound angle,using positive and negative compound angle can improve overall average film cooling effectiveness by about 20%and 25%,respectively.The effects of the secondary flow also can be weakened.A stagger film trajectory arrangement can achieve more uniform film coverage with higher overall film cooling effectiveness.The film trajectory arrangement of a positive compound angle injection is determined by the combined effect of hole arrangement and blowing ratio.While,the film trajectory arrangement of a negative compound angle injection is almost the same as the hole arrangement and nearly does not change with the blowing ratio.
基金Foundation item:the Natural Science Foundation of Jiangsu Province(BK97056109)
文摘A vorticity-velocity method was used to study the incompressible viscous fluid flow around a circular cylinder with surface suction or blowing. The resulted high order implicit difference equations were effeciently solved by the modified incomplete LU decomposition conjugate gradient scheme ( MILU-CG). The effects of surface suction or blowing' s position and strength on the vortex structures in the cylinder wake, as well as on the drag and lift forces at Reynoldes number Re = 100 were investigated numerically. The results show that the suction on the shoulder of the cylinder or the blowing on the rear of the cylinder can effeciently suppress the asymmetry of the vortex wake in the transverse direction and greatly reduce the lift force; the suction on the shoulder of the cylinder, when its strength is properly chosen, can reduce the drag force significantly, too.
文摘This work is concerned with Magnetohydrodynamic viscous flow due to a shrinking sheet in the presence of suction. The cases of two dimensional and axisymmetric shrinking are discussed. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are numerically solved by using an advanced numeric technique. Favorability comparisons with previously published work are presented. Numerical results for the dimensionless velocity, temperature and concentration profiles as well as for the skin friction, heat and mass transfer and deposition rate are obtained and displayed graphically for pertinent parameters to show interesting aspects of the solution.
基金National Natural Science Foundation of China(51806233)National Major Science and Technology Project(2017-III-0003-0027)。
文摘The interaction between the cooling film on the suction surface of the transonic turbine cascade and the shock wave in the passage is analyzed by numerical calculation method.The effects of cooling pressure and incident angle on the shock wave shape and the film cooling efficiency under the action of shock wave are studied.The results show that with the increase of exit Mach number,the incident position of the left shock wave at the trailing edge of the cascade moves backward relative to the leading edge of the adjacent cascade,and the shock wave intensity increases;there is a temperature jump behind the temperature peak at the exit Mach number of 1.05 and 1.2,the main reason is that with the increase of shock wave intensity,the interaction between shock wave and boundary layer intensifies,and the boundary layer appears local separation,in the separation region,the mixing of high-temperature mainstream and boundary layer flow intensifies,which makes the temperature in the separation region of suction surface increase;the results show that different cooling gas injection positions have great influence on the shock wave shape in the channel,and the cooling area of the wall is smaller than that before and after the shock wave,which is mainly due to the reduction of the film coverage area under the impact of the incident shock wave,after the impact zone of shock wave,the cooling film is compressed by the main stream and attached to the wall again,resulting in the discontinuous film coverage at the shock wave incident point;the film cooling efficiency decreases significantly with the increase of cooling flow angle from 25°to 35°and changes little with the increase of cooling flow angle from 35°to 45°;the cooling efficiency does not increase infinitely with the increase of blowing ratio,when the blowing ratio is greater than a certain value,the influence of blowing ratio on cooling efficiency gradually decreases.
