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profile and Secondary Flow losses in a High-Lift LPT Blade Cascade at Different Reynolds Numbers under Steady and Unsteady Inflow Conditions

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Journal of Thermal Science 2012年第6期21卷 483-491页

作者： Satta F. Simoni D. Ubaldi M. Zunino P. Bertini F. DIMSET-Università di Genova Via Montallegro 1I-16145 GenovaItaly Avio S.p.A. Viale I Maggio 56I-10040 Rivalta(TO)-Italy

The aerodynamic flow field downstream of a Low-Pressure High-Lift(HL)turbine cascade has been experimentally investigated for different Reynolds numbers under both steady and unsteady inflows,in order to analyse the cascade performance under real engine operating *** Reynolds number has been varied in the range 100000profile and secondary flow losses have been *** pressure,velocity and secondary kinetic energy distributions at the downstream tangential plane have been measured by means of a miniaturized 5-hole *** quantities provide information on both blade wake and secondary flow structures(passage and horse-shoe vortices).The analysis of the results allows the evaluation of the aerodynamic performance of the HL front-loaded blade in terms of both profile and secondary losses.

关键词： profile losses secondary flow losses high-lift profdes unsteady inflow LPT blade.

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Aerodynamic Loading Distribution Effects on the Overall Performance of Ultra-High-Lift LP Turbine Cascades

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Journal of Thermal Science 2014年第1期23卷 1-12页

作者： M.Berrino F.Satta D.Simoni M.Ubaldi P.Zunino F.Bertini DIME Università degli Studi di Genova Via Montallegro 1I-16145 GenovaItaly Avio S.p.A. Professors I Maggio 56I-10040 Rivalta (TO) Italy

The present paper reports the results of an experimental investigation aimed at comparing aerodynamic perform- ance of three low-pressure turbine cascades for several Reynolds numbers under steady and unsteady inflows. This study is focused on finding design criteria useful to reduce both profile and secondary losses in the aero-engine LP turbine for the different flight conditions. The baseline blade cascade, characterized by a standard aerodynamic loading （Zw=1.03）, has been compared with two Ultra-High-Lift profiles with the same Zweifel number （Zw=1.3 for both cascades）, but different velocity peak positions, leading to front and mid-loaded blade cascade configurations. The aerodynamic flow fields downstream of the cascades have been experimentally in- vestigated for Reynolds numbers in the range 70000〈Re〈300000, where lower and upper limits are typical of cruise and take-off/landing conditions, respectively. The effects induced by the incoming wakes at the reduced frequency ./＋=0.62 on both profile and secondary flow losses for the three different cascade designs have been studied. Total pressure and velocity distributions have been measured by means of a miniaturized 5-hole probe in a tangential plane downstream of the cascade for both inflow conditions. The analysis of the results allows the evaluation of the aerodynamic performance of the blade cascades in terms of profile and secondary losses and the understanding of the effects of loading distribution and Zweifel number on secondary flows. When operating un- der unsteady inflow, contrarily to the steady case, the mid-loaded cascade has been found to be characterized by the lowest profile and secondary losses, making it the most attractive solution for the design of blades working in real conditions where unsteady inflow effects are present.

关键词： Low-Pressure Turbine Ultra-High-Lift Prof'des profile losses Secondary losses Mid-Loaded Blade Cascades Aft-Loaded Blade Cascades.

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Free-stream Turbulence Effects on the Boundary Layer of a High-lift Low-Pressure-Turbine Blade

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Journal of Thermal Science 2016年第3期25卷 195-206页

作者： Simoni D. Ubaldi M. Zunino p. Ampellio E. DIME-Universita di Genova Via MontaUegro 11-16145 GenovaItaly GE AvioAero S.p.A. V.I Maggio99 1-10040 Rivalta(TO)-Italy

The suction side boundary layer evolution of a high-lift low-pressure turbine cascade has been experimentally in- vestigated at low and high free-stream turbulence intensity conditions. Measurements have been carded out in order to analyze the boundary layer transition and separation processes at a low Reynolds nttmber, under both steady and unsteady inflows. Static pressure distributions along the blade surfaces as well as total pressure distri- butions in a downstream tangential plane have been measured to evaluate the overall aerodynamic efficiency of the blade for the different conditions. Particle. Image Velocimetry has been adopted to analyze the time-mean and time-varying velocity fields. The flow field has been surveyed in two orthogonal planes （a blade-to-blade plane and a wall-parallel one）. These measurements allow the identification of the Kelvin-Helmholtz large scale cohe- rent structures shed as a consequence of the boundary layer laminar separation under steady inflow, as well as the investigation of the three-dimensional effects induced by the intermittent passage of low and high speed streaks. A close inspection of the time-mean velocity profiles as well as of the boundary layer integral parameters helps to characterize the suction side boundary layer state, thus justifying the influence of free-stream turbulence intensity on the blade aerodynamic losses measured under steady and unsteady inflows.

关键词： profile losses high-lift profiles free-stream turbulence streaks unsteady flows.

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Experimental Investigation of Aerodynamic Characteristic of A High-loaded Working Cascade with Reactance 0.45

Experimental Investigation of Aerodynamic Characteristic of ...

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2010亚太航空航天技术研讨会

作者： Zheng Guanghua~(1*) He Yihong~2 1 Department of Engine and Energy Northwestern Polytechnical University Xi’an 710072 China 2 Chinese Aviation Power Institude(CAPI) Zhuzhou 412002 China

＜正＞Experimental investigation of aerodynamic characteristic of a high-loaded workingcascade with reactance 0.45 is *** are carried out in a wide range of Mach number on the exit（Ma=0.7～1.3）.The flow structure in the blade passage is analyzed and the method to optimize the design of the working cascade is *** of profile losses under subsonic conditions（Ma= 0.7～1.0） is 0.04～*** supersonic conditions（Ma= 1.0～1.3） profile losses sharply increase and reach approximately *** of secondary losses under subsonic conditions is rather high and reaches *** losses under supersonic conditions essentially decrease and obtain *** indicates increase in aerodynamic convergence and reduction in proportion of frictional losses in total losses. To decrease wave losses in the investigated cascade,it is necessary to reduce the value of angle of curvature to 2 /°～3°;increase the value of angle of blade passage to 4°～5°.

关键词： high-loaded aerodynamic characteristic flow structure profile losses secondary losses

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