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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 100000pper limits are typical of cruise and take-off/landing conditions,*** effects induced by the incoming wakes at the reduced frequency f+=0.62 on both profile 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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Experimental Analysis of the Aerodynamic performance of an Innovative Low pressure Turbine Rotor

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Journal of Thermal science 2016年第1期25卷 22-31页

作者： Infantino Daniele satta Francesca simoni Daniele Ubaldi Marina Zunino pietro Bertini Francesco DIME-Universita degli studi di Genova Via MontaUegro 11-16145 GenovaItaly avio Aero Viale I Maggio 56I-10040 Rivalta(TO)-Italy

In the present work the aerodynamic performances of an innovative rotor blade row have been experimentally investigated. Measurements have been carried out in a large scale low speed single stage cold flow facility at a Reynolds number typical of aeroengine cruise, under nominal and off-design conditions. The time-mean blade aerodynamic loadings have been measured at three radial positions along the blade height through a pressure transducer installed inside the hollow shaft, by delivering the signal to the stationary frame with a slip ring. The time mean aerodynamic flow fields upstream and downstream of the rotor have been measured by means of a five-hole probe to investigate the losses associated with the rotor. The investigations in the single stage research turbine allow the reproduction of both wake-boundary layer interaction as well as vortex-vortex interaction. The detail of the present results clearly highlights the strong dissipative effects induced by the blade tip vortex and by the momentum defect as well as the turbulence production, which is generated during the migration of the stator wake in the rotor passage. phase-locked hot-wire investigations have been also performed to analyze the time-varying flow during the wake passing period. In particular the interaction between stator and rotor structures has been investigated also under off-design conditions to further explain the mechanisms contributing to the loss generation for the different conditions.

关键词： Low pressure Turbine single stage Research Turbine Rotor Aerodynamic Loading Hot-wire Anemometry

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Film cooling adiabatic effectiveness measurements of pressure side trailing edge cooling configurations

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propulsion and power Research 2015年第4期4卷 190-201页

作者： R.Becchi B.Facchini A.picchi L.Tarchi D.Coutandin s.Zecchi Department of Industrial Engineering University of FlorenceVia S.Marta 350139FirenzeItaly GE avio s.r.l. Via I Maggio 9910040Rivalta di TorinoTorinoItaly

Nowadays total inlet temperature of gas turbine is far above the permissible metal temperature;as a consequence,advanced cooling techniques must be applied to protect from thermal stresses,oxidation and corrosion the components located in the high pressure stages,such as the blade trailing edge.A suitable design of the cooling system for the trailing edge has to cope with geometric constraints and aerodynamic demands;state-of-the-art of cooling concepts often use film cooling on blade pressure side:the air taken from last compressor stages is ejected through discrete holes or slots to provide a cold layer between hot mainstream and the blade *** the goal of ensuring a satisfactory lifetime of blades,the design of efficient trailing edge film cooling schemes and,moreover,the possibility to check carefully their behavior,are hence necessary to guarantee an appropriate metal temperature *** this purpose an experimental survey was carried out to investigate the film covering performance of different pressure side trailing edge cooling systems for turbine *** experimental test section consists of a scaled-up trailing edge model installed in an open loop suction type test *** of adiabatic effectiveness distributions were carried out on three trailing edge cooling system *** baseline geometry is composed by inclined slots separated by elongated pedestals;the second geometry shares the same cutback configuration,with an additional row of circular film cooling holes located upstream;the third model is equipped with three rows of in-line film cooling *** have been performed at nearly ambient conditions imposing several blowing ratio values and using carbon dioxide as coolant in order to reproduce a density ratio close to the engine conditions(DR¼1.52).To extend the validity of the survey a comparison between adiabatic effectiveness measurements and a prediction by correlative approach was performed to comp

关键词： Turbine blades Trailing edge Film cooling pressure sensitive paint(psp)

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Assessment of the Biological Damage in Whiplash syndrome: Role of Digital Infrared Thermal Imaging (DITI) and Ultrasonography (Us)

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Open Journal of Radiology 2013年第4期3卷 222-230页

作者： Gian Carlo parenti Enzo Gualtieri Francesco Fontana Aleardo Benelli Fabrizio Albarello Department of Radiology OC”S.Maria delle Croci” Ravenna Italy Department of Radiology S.Anna Hospital University of Ferrara Ferrara Italy Health Center Medicina-Ravenna and Kura-Cesena Cesena Italy

Objectives: To compare DITI vs Us in a cohort of patients with whiplash syndrome for assessing soft tissues injuries of the cervical and dorsal spine. Methods: 70 patients presenting to clinic with traumatic cervical and/or dorsal spine injury and with a clinical diagnosis of whiplash syndrome underwent both DITI (avio TVs 2000) and Us (GE Logic 5) of the following muscles: sternocleidomastoid, splenius, trapezius, longus colli and paravertebral muscles. DITI considered positive in the region with the most altered temperature among the injured area examinated (normal range 0℃ - 0.8℃). Us valued the cervical and dorsal region with a comparative examination of the soft tissues. The images taken with DITI were compared with the clinical and the sonographic outcomes respectively. Us and DITI were considered a) congruent whether both had a positive outcome for the same muscle clinically injured;b) not congruent whether one of the two instruments had a different outcome then the clinical evidence. Wilcoxon paired test was used for statistical analysis. Results: DITI and Us matched 153 of 233 (65%) injured muscles. The association between DITI and Us in the evaluation of the injured muscles was statistically significant for the following muscles: left trapezius (p Conclusions: According to our preliminary study, DITI and Us were both helpful for assessing soft tissues injuries in patients with whiplash syndrome, defining the extent of the biologic damage for a correct clinical-therapeutical management.

关键词： Whiplash syndrome Digital Infrared Termography Imaging Ultrasongraphy Legal Medicine

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