Has also been attributed to his uncle (or great-uncle) of the same name, who died 1420.--NUC pre-1956. Book.
0000 - Gale Group | The Making of Modern World
Davide Lengani, Daniele Simoni, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
Results from Particle Image Velocimetry (PIV) investigations have been discussed in order to characterize the dynamics driving the transition process in a strong adverse pressure gradient condition exposed to high Free Stream Turbulence Intensity (FSTI) level. Measurements have been carried out in the suction side boundary layer of a low pressure turbine cascade. Two orthogonal planes are analyzed in order to study both lift-up mechanisms of low speed streaks (in the wall-normal plane) as well as instability ...
Tópico(s): Computational Fluid Dynamics and Aerodynamics
2017 - Elsevier BV | Experimental Thermal and Fluid Science
Davide Lengani, Daniele Simoni, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
Proper Orthogonal Decomposition has been applied to Time-Resolved Particle Image Velocimetry data describing the dynamics of laminar separation bubbles. The mutual orthonormality of the POD modes of the velocity components has been accounted for to separate the contributions to the Reynolds stress tensor due to the different modes, thus to the stress production and the mean flow energy dissipation. The low frequency motion of the separated shear layer, the shedding phenomenon and the formation of ...
Tópico(s): Fluid Dynamics and Vibration Analysis
2017 - Elsevier BV | International Journal of Heat and Fluid Flow
Daniele Simoni, Davide Lengani, Marina Ubaldi, Pietro Zunino, Matteo Dellacasagrande,
Tópico(s): Particle Dynamics in Fluid Flows
2017 - Springer Science+Business Media | Experiments in Fluids
Davide Lengani, Daniele Simoni, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
Tópico(s): Turbomachinery Performance and Optimization
2016 - Springer Science+Business Media | Flow Turbulence and Combustion
Daniele Simoni, Marina Ubaldi, Pietro Zunino,
A semi-empirical model for the estimation of the Kelvin–Helmholtz (KH) instability frequency, in the case of short laminar separation bubbles over airfoils, has been developed. To this end, the Thwaites's pressure gradient parameter has been adopted to account for the effects induced by the aerodynamic loading distribution as well as by the Reynolds number on the separated shear layer thickness at separation. The most amplified frequency predicted by linear stability theory (LST) for a piecewise linear ...
Tópico(s): Fluid Dynamics and Vibration Analysis
2015 - ASM International | Journal of Turbomachinery
Daniele Simoni, Marco Berrino, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
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 ...
Tópico(s): Fluid Dynamics and Turbulent Flows
2014 - ASM International | Journal of Turbomachinery
Davide Lengani, Daniele Simoni, Marina Ubaldi, Pietro Zunino,
Particle Image Velocimetry (PIV) measurements have been performed in order to analyze the unsteady flow field developing along the separated flow region of a laminar separation bubble. Data have been post-processed by means of Proper Orthogonal Decomposition (POD) to improve the understanding of the physics of this complex phenomenon. The paper shows that the first two POD modes of the normal to the wall velocity component are coupled. Thus, they are representative of a vortex shedding phenomenon ...
Tópico(s): Lattice Boltzmann Simulation Studies
2014 - Elsevier BV | Experimental Thermal and Fluid Science
Daniele Simoni, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
Tópico(s): Heat Transfer Mechanisms
2012 - Springer Science+Business Media | Experiments in Fluids
Daniele Simoni, Marina Ubaldi, Pietro Zunino,
Tópico(s): Heat Transfer Mechanisms
2012 - Springer Science+Business Media | Flow Turbulence and Combustion
Daniele Simoni, Marina Ubaldi, Pietro Zunino, Davide Lengani, Francesco Bertini,
Tópico(s): Turbomachinery Performance and Optimization
2011 - Springer Science+Business Media | Flow Turbulence and Combustion
Davide Lengani, Daniele Simoni, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
Abstract The present paper analyses the results of a detailed experimental study on low profile vortex generators used to control the turbulent boundary layer separation on a large-scale flat plate with a prescribed adverse pressure gradient, typical of aggressive turbine intermediate ducts. This activity is part of a joint European research program on Aggressive Intermediate Duct Aerodynamics (AIDA). Laser Doppler Velocimetry and a Kiel total pressure probe have been employed to perform measurements ...
Tópico(s): Turbomachinery Performance and Optimization
2011 - Elsevier BV | Experimental Thermal and Fluid Science
Francesca Satta, Daniele Simoni, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
Tópico(s): Aerodynamics and Acoustics in Jet Flows
2010 - Springer Science+Business Media | Journal of Thermal Science
Abstract The paper reports the results of an experimental investigation of the time-varying characteristics of the flow in the turbulent near wake behind the central blade of a large-scale turbine cascade. The blade wake has been surveyed by means of a two-component laser Doppler velocimeter (LDV) over a close experimental grid extending from the blade trailing edge to six trailing edge diameters downstream. A phase-locked ensemble averaging technique has been applied to the LDV instantaneous data ...
Tópico(s): Wind and Air Flow Studies
2000 - Elsevier BV | Experimental Thermal and Fluid Science
Marina Ubaldi, Pietro Zunino, Andrea Ghiglione,
The flow within the impeller and the vaneless diffuser of a centrifugal turbomachine model operating at the nominal point has been experimentally investigated. The radial and circumferential velocities and the associated turbulent fluctuations have been measured on seven cross-sectional circumferential surfaces, four within the impeller and three in the vaneless diffuser by means of a four-beam two-color fibre optic laser-Doppler velocimeter. To complete the flow investigation, LDV measurements ...
Tópico(s): Combustion and flame dynamics
1998 - Elsevier BV | Experimental Thermal and Fluid Science
Davide Lengani, Daniele Simoni, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
Tópico(s): Plasma and Flow Control in Aerodynamics
2011 - Springer Science+Business Media | Flow Turbulence and Combustion
A. Perdichizzi, Marina Ubaldi, Pietro Zunino,
The results are presented of an experimental investigation on the three-dimenstional turbulent flow developing downstream of a turbine cascade. The cascade has an aspect ratio of 1.05 and the flow turning is about 84°. Measurements were performed in four planes located respectively at 10, 30, 54, and 90% of an axial chord downstream of the blade trailing edge. The mean velocity field and the energy loss coefficient distributions were obtained by five-hole pressure probe measurements, while the six ...
Tópico(s): Heat Transfer Mechanisms
1992 - Elsevier BV | Experimental Thermal and Fluid Science
Edward Canepa, P. Di Martino, Piergiorgio Formosa, Marina Ubaldi, Pietro Zunino,
Lean premixing prevaporizing (LPP) burners represent a promising solution for low-emission combustion in aeroengines. Since lean premixed combustion suffers from pressure and heat release fluctuations that can be triggered by unsteady large-scale flow structures, a deep knowledge of flow structures formation mechanisms in complex swirling flows is a necessary step in suppressing combustion instabilities. The present paper describes a detailed investigation of the unsteady aerodynamics of a large- ...
Tópico(s): Aerodynamics and Acoustics in Jet Flows
2004 - ASM International | Journal of Engineering for Gas Turbines and Power
Davide Lengani, Daniele Simoni, Alessandro Nilberto, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
Tópico(s): Turbomachinery Performance and Optimization
2018 - Springer Science+Business Media | Experiments in Fluids
Daniele Simoni, Marina Ubaldi, Pietro Zunino,
The present paper reports the results of a detailed experimental study on the interaction process between incoming wakes and a laminar separated boundary layer. Experimental investigations have been carried out, for a low Reynolds number case, over a flat plate installed within a double contoured test section designed to produce an adverse pressure gradient typical of Ultra-High-Lift turbine blade profiles. Measurements have been performed by means of a single-sensor hot-wire anemometer. The phase- ...
Tópico(s): Heat Transfer Mechanisms
2013 - Elsevier BV | Experimental Thermal and Fluid Science
Davide Lengani, Daniele Simoni, Marina Ubaldi, Pietro Zunino, Francesco Bertini,
A time-resolved particle image velocimetry (TR-PIV) system has been employed to investigate the unsteady propagation of upstream wakes in a low-pressure turbine cascade. Data are obtained in the steady state condition and for two passing wake reduced frequencies. The study is focused on the identification and split of the different dynamics responsible for deterministic and random oscillations, thus loss generation by means of a new procedure based on proper orthogonal decomposition (POD). The paper ...
Tópico(s): Computational Fluid Dynamics and Aerodynamics
2017 - Multidisciplinary Digital Publishing Institute | International Journal of Turbomachinery Propulsion and Power
Bernardo Monechi, Enrico Ubaldi, Pietro Gravino, Ilan Chabay, Vittorio Loreto,
Abstract The adverse effects of unsustainable behaviors on human society are leading to an increasingly urgent and critical need to change policies and practices worldwide. This requires that citizens become informed and engaged in participatory governance and measures leading to sustainable futures. Citizens’ understanding of the inherent complexity of sustainable systems is a necessary (though generally not sufficient) ingredient for them to understand controversial public policies and maintain ...
Tópico(s): Land Use and Ecosystem Services
2021 - Nature Portfolio | Scientific Reports
Dario Barsi, Marina Ubaldi, Pietro Zunino, Robert Fink,
In the present paper, an optimized design procedure capable of providing the geometry of a high efficiency compact hydraulic propeller turbine for low head is proposed and developed. The turbine preliminary design is based on fundamental turbomachinery mean-line equations and on the employment of statistical correlations, which relate the main geometrical parameters to the fundamental design parameters. The first obtained geometry represents the starting point of an automated aerodynamic single ...
Tópico(s): Computational Fluid Dynamics and Aerodynamics
2021 - Multidisciplinary Digital Publishing Institute | Designs
Edward Canepa, Piergiorgio Formosa, Davide Lengani, Daniele Simoni, Marina Ubaldi, Pietro Zunino,
The unsteady flow within a two-stage low-pressure research turbine equipped with high lift profiles has been investigated in detail for three different aerodynamic loading conditions. Experiments have been carried out at low speed. Velocity and turbulence intensity in the blade-to-blade plane at midspan have been measured by means of a crossed hot-wire probe, upstream and downstream of each blade row. The probe has been traversed circumferentially over 1.5 bladings pitch and the phase-locked data ...
Tópico(s): Fluid Dynamics and Turbulent Flows
2006 - ASM International | Journal of Turbomachinery
Francesca Satta, Daniele Simoni, Marina Ubaldi, Pietro Zunino,
Tópico(s): Heat Transfer Mechanisms
2008 - Springer Science+Business Media | Journal of Thermal Science
Marina Ubaldi, Pietro Zunino, Andrea Cattanei,
Abstract This article presents the results of an experimental investigation on the relative flow within and behind an axial fan rotating row. The flow within the rotor passages has been surveyed over blade-to-blade surfaces with a laser-Doppler velocimeter (LDV), while the flow leaving the rotating blades has been measured by means of stationary hot-wire probes and fast-response miniature pressure transducers. A phase-locked sampling and ensemble-average technique has been applied to separate periodic ...
Tópico(s): Fluid Dynamics and Turbulent Flows
1994 - Elsevier BV | Experimental Thermal and Fluid Science
Barbara Ubaldi, Enzo Maria Le Fevre, E. Petrucci, Pietro Marchionni, Claudio Biancalana, Nanni Hiltunen, Daniela Maria Intravaia, Chan Yeong Yang,
This Working Paper is intended to highlight the main opportunities and challenges for the use of emerging technologies (ET), and in particular emerging digital technologies, in the public sector. Based on the first results of the analysis of evidence collected in 20 countries, the paper offers a few insights on the state of the art on the strategies and practical examples on how governments are attempting to integrate ET in the public sector.
Tópico(s): ICT Impact and Policies
2019 - | OECD working papers on public governance
Edward Canepa, Davide Lengani, Alessandro Nilberto, Daniele Petronio, Daniele Simoni, Marina Ubaldi, Pietro Zunino,
The paper presents a detailed analysis of particle image velocimetry (PIV) measurements performed in a turbine cascade representative of highly accelerated low-pressure turbine (LPT) blades. Two cameras have been simultaneously used to observe a great portion of the suction side boundary layer with the highest possible spatial resolution, thus allowing us to solve the interaction process between impinging upstream wakes and the blade boundary layer. Four unsteady inflow conditions, characterized by ...
Tópico(s): Combustion and flame dynamics
2021 - Multidisciplinary Digital Publishing Institute | International Journal of Turbomachinery Propulsion and Power
Dario Barsi, Marina Ubaldi, Pietro Zunino, Robert Fink,
In this paper, a design procedure for a compact hydraulic propeller turbine for low heads is proposed and developed. The design is based upon classical criteria and on the employment of statistical correlations, which relates the main geometrical parameters to the fundamental design parameters of turbomachinery. The procedure for obtaining the meridional flow path and the stator vanes and rotor blades geometries is explained step by step. The obtained 3D model is employed to carry out a CFD calculation ...
Tópico(s): Turbomachinery Performance and Optimization
2019 - EDP Sciences | E3S Web of Conferences
R. Anniballo, F. Ubaldi, Jan Tesařík, Pietro Micheli, Laura Rienzi, Ermanno Greco, M Sorrentino,
The article by Bar-Shira Maymon et al. (1Bar-Shira Maymon B. Yogev L. Paz G. Kleiman S. Schreiber L. Botchan A. et al.Sertoli cell maturation in men with azoospermia of different etiologies.Fertil Steril. 2002; 77: 904-909Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar) is noteworthy in attempting to differentiate the Sertoli cell functional status between normal and pathological biopsies. Once this was a task of diagnostic histology that was based on morphological appearance alone. ...
Tópico(s): Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
2003 - Elsevier BV | Fertility and Sterility