Shock System Model of Highly Loaded Turbine Cascade

2020 ◽  
Vol 33 (1) ◽  
pp. 04019107
Author(s):  
ZhiHong Zhou ◽  
HuoXing Liu ◽  
Kun Zhou ◽  
Chao Li
Keyword(s):  
System Model ◽  
Turbine Cascade ◽  
Shock System ◽  
Highly Loaded

Application of the Quantitative Monochrome Calibrated Schlieren Technique in a Highly Loaded Turbine Cascade Test

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Zhihong Zhou ◽  
Haotian Wang ◽  
Huoxing Liu
Keyword(s):  
Shock Wave ◽  
Image Processing ◽  
Boundary Condition ◽  
Density Field ◽  
Dominant Factor ◽  
Turbine Cascade ◽  
Schlieren Technique ◽  
Computer Image Processing ◽  
Density Boundary ◽  
Highly Loaded

Abstract As the load of the turbine components of aircraft engines continuously increases, shock loss becomes the dominant factor of turbine stage loss and has become a hot topic. The Schlieren technique is one of the few effective experimental methods to observe and study shock wave and, thus, has been widely used. Nevertheless, limited by camera accuracy and computer image processing technology, quantitative schlieren analysis methods were difficult to achieve in engineering applications. Fortunately, several quantitative schlieren methods have been developed with the help of new digital technology. Applying the schlieren technique to the highly loaded turbine cascade test is of great significance to the study of shock wave in highly loaded turbine cascades. In this paper, the results of the quantitative density field and shock intensity and loss in the cascade are obtained by using a double-reflection-type monochrome schlieren device. The boundary condition of the density field is obtained by pressure test, and matlab software is used as image processing calculation tool. The quantitative results of this paper prove the feasibility of applying quantitative schlieren method to highly loaded turbine cascade tests. Also, the implemented image processing method and density boundary condition acquisition method are suitable and convenient for cascade flow and shock measurement tests.

Application of Quantitative Monochrome Calibrated Schlieren Technique in Highly-Loaded Turbine Cascade Test

2019 ◽  
Author(s):  
Zhihong Zhou ◽  
Haotian Wang ◽  
Huoxing Liu
Keyword(s):  
Shock Wave ◽  
Image Processing ◽  
Boundary Condition ◽  
Density Field ◽  
Dominant Factor ◽  
Turbine Cascade ◽  
Schlieren Technique ◽  
Computer Image Processing ◽  
Density Boundary ◽  
Highly Loaded

Abstract As the load of the turbine components of aircraft engines continuously increases, shock loss becomes the dominant factor of turbine stage loss and has become a hot topic. Schlieren technique is one of the few effective experimental methods to observe and study shock wave and, thus, has been widely used. Nevertheless, limited by camera accuracy and computer image processing technology, quantitative schlieren analysis methods were difficult to achieve in engineering applications. Fortunately, several quantitative schlieren methods have been developed with the help of new digital technology. Applying schlieren technique to the highly-loaded turbine cascade test is of great significance to the study of shock wave in highly-loaded turbine cascades. In this paper, the results of quantitative density field and shock intensity and loss in the cascade are obtained by using a double reflection type monochrome schlieren device. The boundary condition of density field is obtained by pressure test, and MATLAB software is used as image processing calculation tool. The quantitative results of this paper prove the feasibility of applying quantitative schlieren method to highly-loaded turbine cascade tests. Also, the implemented image processing method and density boundary condition acquisition method are suitable and convenient for cascade flow and shock measurement tests.

Blade Bowing Effect on Aerodynamic Performance of a Highly Loaded Turbine Cascade

2010 ◽  
Vol 26 (3) ◽  
pp. 604-608 ◽  
Author(s):  
Chunqing Tan ◽  
Hualiang Zhang ◽  
Hongde Xia ◽  
Haisheng Chen ◽  
Atsumasa Yamamoto
Keyword(s):  
Aerodynamic Performance ◽  
Turbine Cascade ◽  
Highly Loaded

Off-Design Performance of a Highly Loaded Low Pressure Turbine Cascade Under Steady and Unsteady Incoming Flow Conditions

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Daniele Simoni ◽  
Marco Berrino ◽  
Marina Ubaldi ◽  
Pietro Zunino ◽  
Francesco Bertini
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Incidence Angle ◽  
Incoming Flow ◽  
Turbine Cascade ◽  
Flow Conditions ◽  
Angle Variation ◽  
Unsteady Inflow ◽  
Lp Turbine ◽  
Highly Loaded

The off-design performance of a highly loaded low pressure (LP) turbine cascade has been experimentally investigated, at the Aerodynamics and Turbomachinery Laboratory of Genova University, under steady and unsteady incoming flow conditions. Tests have been performed for different Reynolds numbers (Re = 70,000 and Re = 300,000), in order to cover the typical LP turbine working range. The incidence angle has been varied between i = −9 deg and +9 deg, in order to test off-design conditions characterizing the engine. For the unsteady case, upstream wake periodic perturbations have been generated by means of a tangential wheel of radial rods. The cascade and the moving bars system have been located over a common bearing in order to make them rigidly rotating. This solution allows a proper comparison of the cascade robustness at the incidence angle variation under steady and unsteady incoming flows, since all the other operating parameters have been kept the same. In order to survey the variation of the unsteady boundary conditions characterizing the off-design operation of the downstream cascade, time-mean and time-resolved wake structures have been analyzed in detail. For what concerns the cascade performance, profile aerodynamic loadings and total pressure loss coefficients at the cascade exit have been surveyed for the different incidence angles under both steady and unsteady inflows. Different total pressure loss sensitivity at the incidence angle variation has been observed for the steady and the unsteady inflow conditions. Hot-wire anemometer has been employed to obtain the time-mean pressure and suction side boundary layer velocity profiles at the blade trailing edge for the different conditions. The integral parameters at the cascade exit plane help to justify the different loss trend versus incidence angle found for the steady and the unsteady cases, explaining the different sensibility of the blade profile when this operates under realistic unsteady inflow condition.

Complex Secondary Flow and Associated Loss Generation in Ultra-Highly Loaded Turbine Cascade

2010 ◽  
Author(s):  
Hoshio Tsujita ◽  
Atsumasa Yamamoto
Keyword(s):  
Secondary Flow ◽  
Static Pressure ◽  
Incidence Angle ◽  
Blade Surface ◽  
Turbine Cascade ◽  
Blade Loading ◽  
Oil Flow ◽  
Oil Flow Visualization ◽  
Secondary Flow Structure ◽  
Highly Loaded

An increase of turbine blade loading decreases the numbers of blades and stages, and results in the improvement of the performance characteristics of gas turbines. However, in such highly loaded turbine cascade with high turning angle, the secondary flow becomes much strong due to the steep pressure gradient across the blade-to-blade passage and deteriorates the performance of turbine enormously. In this study, the computations were performed for the flow in the ultra-highly loaded turbine cascade in order to clarify the effects of the inlet boundary layer thickness and the incidence angle which strongly influence the secondary flow structure in a turbine cascade. Moreover, the experimental oil flow visualization was conducted on the blade surface and the endwall, and the measurements of blade surface static pressure were performed at the midspan. The computed results agreed well with the oil flow visualization and the measured blade surface static pressure. The effects of the incidence angle and the inlet boundary layer thickness on the secondary flow structure, the total pressure loss, the secondary flow kinetic energy and the blade loading distributions were examined in detail. The positive incidence angle induced the characteristic vortex released from the endwall. Moreover, it was revealed that the interactions among the horseshoe vortex, the passage vortex and the characteristic vortex strongly increase the secondary loss in the cascade passage.

Profile Loss of Ultra-Highly Loaded Turbine Cascade at Transonic Flow Condition

2019 ◽  
Author(s):  
Hoshio Tsujita ◽  
Masanao Kaneko
Keyword(s):  
Mach Number ◽  
Transonic Flow ◽  
Compressible Flows ◽  
Detailed Examination ◽  
Aerodynamic Performance ◽  
Turbine Cascade ◽  
Wide Range ◽  
Exit Mach Number ◽  
Profile Loss ◽  
Highly Loaded

Abstract The aerodynamic performance of turbine components constituting the gas turbine engine is seriously required to be improved in order to reduce environmental load. The energy recovery efficiency in turbine component can be enhanced by the increase of turbine blade loading. In this study, as the first stage to investigate the aerodynamic performance of an ultra-highly loaded turbine cascade (UHLTC) with a turning angle of 160 degrees at transonic flow regime, two-dimensional steady compressible flows in UHLTC were analyzed numerically by using a commercial CFD code to focus on the profile loss. In the computations, the isentropic exit Mach number was varied in the wide range from 0.3 to 1.8 in order to examine the effects of exit Mach number on the shock wave formation and the associated profile loss generation. The computed results were examined in detail by comparing with those for a typical transonic turbine cascade. The detailed examination for the present computed results clarified the variation of shock pattern with the increase of exit Mach number and the loss “plateau” behavior in the present UHLTC.

Sign in / Sign up

Export Citation Format

Share Document