Giovanni Bernardini

Giovanni Bernardini
Università Degli Studi Roma Tre | UNIROMA3 · Department of Engineering

Prof.

About

177
Publications
18,798
Reads
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1,201
Citations
Additional affiliations
November 2012 - January 2015
Università Degli Studi Roma Tre
Position
  • Researcher
March 2003 - March 2004
Sapienza University of Rome
Position
  • Fellowship in Aeronautical Engineering
December 1999 - present
Università Degli Studi Roma Tre
Position
  • Researcher

Publications

Publications (177)
Article
Full-text available
This paper presents a numerical investigation of noise radiated by two side-by-side propellers, suitable for Distributed-Electric-Propulsion concepts. The focus is on the assessment of the variation of the effects of blade tip Mach number on the radiated noise for variations of the direction of rotation, hub relative position, and the relative phas...
Conference Paper
The aim of the proposed paper is the development of a general approach capable of determining the set of trim commands, aerodynamic controls surfaces actuation and/or engine thrust regulation, that allow specific steady-state flight conditions of non-conventional VTOLs, under given performance constraints. Specifically, an energy-based trim algorithm...
Conference Paper
Novel boundary integral formulations suitable for the aerodynamic and aeroacoustic analysis of deformable bodies in arbitrary motion are theoretically/numerically developed. These will be applied to a translating wing subject to unsteady bending and torsion. The influence of the surface deformation on the evaluated perturbation fields will be asses...
Article
The effect of gravity during the water entry of two-dimensional and axisymmetric bodies is investigated analytically and numerically. An extension to the Wagner model of water impact is proposed in order to take into account the effect of gravity. For this purpose, the free-surface condition is modified. The pressure is computed using the modified...
Conference Paper
The present paper deals with a numerical investigation on the effect of the trim control strategy on the noise emitted by a quadrotor system. The proposed approach consists in three steps: first, three different strategies are applied in an optimal trim procedure to evaluate the vehicle attitude and control settings for steady flight conditions; th...
Article
Full-text available
A hierarchical formulation is presented for the large displacement modal and transient analysis of rotating plates having different thicknesses, sizes, and settings angle with respect to the spinning axis. After derivation of the governing equations of motion by the Principle of Virtual Displacements, the finite element discretization yields a set...
Conference Paper
Full-text available
The present paper presents a multisection approach for the hydrodynamics analysis of the vertical water impact of a fuselage where the 3D problem is approximated by a series of 2D cross-section problems. A 2D potential flow solver based on a hybrid BEM-FEM approach is embedded in the multisection procedure to perform the hydrodynamic analysis.. The...
Article
This paper deals with the development of a noise propagation tool for the prediction of perceived noise due to aircraft/rotorcraft flying in a non-uniform atmosphere over a non-flat ground. The far-field noise is predicted through a direct ray tracing method, once the near-field aeroacoustic solution, used to define the aircraft/rotorcraft equivale...
Conference Paper
This paper presents the activities in the GARTEUR Action Group HC/AG-24 to study the noise scattering of helicopter rotors in the presence of the fuselage. The focus of the Action Group is on the development and the validation of numerical prediction methods and on establishing an experimental data base for numerical validations. This paper will fo...
Conference Paper
View Video Presentation: https://doi.org/10.2514/6.2021-2236.vid This paper deals with a numerical investigation on aerodynamics and aerocoustics of multi-propeller/wing configurations. Particular attention is paid to the effect of the aerodynamic interactions on the acoustic emissions and aerodynamic performance which represents, nowadays, one of...
Article
This paper deals with the innovative development of surrogate models suitable for the simulation of aerodynamic performance and acoustic emission in terms of tonal components, of multi-propeller systems like those applicable in urban air-mobility vehicles. These can be of great help particularly when designing distributed-electric-propulsion config...
Article
The fast development of Urban-Air-Mobility as well as the constant growth of the air transport have made the acoustic pollution abatement a crucial requirement for the aviation industries in order to comply with the increasingly demanding constraints for the community acceptance. The aeroacoustic characterization of arrays of electrically-powered p...
Conference Paper
Full-text available
The present paper proposes a new flow separation model for the water impact problem which is here solved through by a potential flow model with fully non-linear boundary conditions at the free-surface. The unsteady boundary value problem is numerically solved through a hybrid BEM-FEM approach where a boundary element method is coupled to a simplifi...
Article
The present paper is dedicated to the development of a numerical model for the water impact of two-dimensional (2D) and axisymmetric bodies with imposed motion. The work is a first step towards the implementation of a 2D+t procedure to be used for the analysis of aircraft ditching. The problem is investigated under the assumptions of an inviscid an...
Preprint
Full-text available
The present paper is dedicated to the development of a numerical model for the water impact of two-dimensional (2D) and axisymmetric bodies with imposed motion. The work is a first step towards the implementation of a 2D+t procedure to be used for the analysis of aircraft ditching. The problem is investigated under the assumptions of an inviscid an...
Article
This paper deals with the theoretical–numerical study of integral formulations for the prediction of noise scattered by moving bodies, through the velocity-potential description of flow disturbance. Specifically, three potential-flow acoustic scattering integral formulations are examined: a linearized boundary-field integral formulation, recently i...
Article
Offshore wind energy is expected to provide a significant contribution to the achievement of the European Renewable Energy targets. One of the main technological issues affecting floating offshore wind turbines concerns generated power fluctuations and structural fatigue caused by sea-wave/platform interactions. This paper presents a fully-coupled...
Article
This work presents the correlation between experimental measurements and numerical simulations concerning the aerodynamics of a hovering rotor operating in ground effect above parallel and inclined surfaces. The capability of a potential-flow, free-wake aerodynamic solver based on a boundary-element-method formulation to simulate in-ground-effect p...
Article
Full-text available
This paper presents an investigation of the aerodynamic and aeroacoustic interaction of propellers for distributed electric propulsion applications. The rationale underlying the research is related to the key role that aeroacoustics plays in the establishment of the future commercial aviation scenario. The sustainable development of airborne transp...
Article
Wake inflow modeling is a crucial issue in the development of efficient and high-fidelity simulation tools for rotorcraft flight dynamics and aeroelasticity. This paper proposes a space-time accurate, finite-state, dynamic wake inflow modeling suitable for conventional and innovative rotor configurations, based on simulations provided by high-fidel...
Conference Paper
Full-text available
In this work an active flutter suppression technique for a Prandtl Plane configuration is presented. The Prandtl Plane aeroelastic model is based upon a modal approach, where the natural modes of vibration of the structure are numerically evaluated through an accurate FEM model of the wing, and the aerodynamic loads are evaluated through a doublet-...
Conference Paper
The present paper focuses on the assessment of the aerodynamic and aeroacoustic interaction of propellers suitable for innovative hybrid-electric aircraft. Attention is paid to the effect on the overall efficiency, the total thrust provided and the acoustic emissions as a function of the relative position for co- and counter-rotating configurations...
Article
This paper presents two novel integral formulations for the prediction of sound scattered by moving bodies, derived from the Lighthill and the Ffowcs Williams and Hawkings equations for the pressure field. These are expressed in the frequency-domain, over a permeable (fictitious) surface surrounding the scatterer(s), and are numerically evaluated t...
Article
The diffusion of electric system on-board has started after 2000, due to the need of fulfilling new regulations regarding environmental impact of aviation and of reducing maintenance costs. This process has led to the More-Electric Aircraft concept design, for which several hydraulic and pneumatic systems have been replaced by electric drives. The...
Article
This paper presents an original approach to structural health monitoring of helicopter rotors based on strain measurement on the blades. Three algorithms are presented, one in the time domain and two in the frequency domain. They are based on the analysis of the discrepancies between the strains on damaged and undamaged blades. Two damage types are...
Article
Transonic shape optimization of nonplanar wings is a relevant topic in current aeronautical world. Although widely studied, an appropriate level of robustness and automation is still lacking for the inclusion of aerodynamic shape optimization in a Multi-Disciplinary Optimization (MDO) process. In this paper, a new framework, opeNsource-mEsh-geneRat...
Article
Full-text available
A review of the natural velocity decomposition (NVD) formulation for the analysis of Navier–Stokes flows developed by the authors is presented. The decomposition consists in expressing the velocity field as the sum of two terms, one of which is given as the gradient of a potential \(\varphi \), whereas the other, \(\mathbf{w}\), is rotational and i...
Article
This paper deals the activities conducted in the GARTEUR Action Group HC/AG-24 to address the noise scattering of helicopter rotors in the presence of the fuselage. The focus of the Action Group is on the development and the validation of numerical prediction methods and establishing an experimental data base for numerical validations. The numerica...
Article
The present work focuses on the alleviation of Blade Vortex Interaction (BVI) noise annoyance through a control methodology generating high-frequency aerodynamic BVI counter-actions. The low-power requirements make the Micro-Trailing Edge Effectors (MiTEs) particularly suited for this kind of application. The controller layout is set by observing t...
Conference Paper
The paper deals with a theoretical-numerical comparison among integral formulations for the prediction of noise scattered by moving bodies. Three acoustic scattering integral formulations for the solution of the velocity potential wave equation are considered: a recently proposed linearized boundary-field integral formulation, and two widely applie...
Conference Paper
Full-text available
This work presents the comparison between experimental measurements and numerical simulations concerning the flowfield generated by a helicopter rotor operating in ground effect conditions above an inclined plane. Specifically, the capability of a potential-based, three-dimensional, free-wake aerodynamic solver to simulate in-ground-effect problems...
Article
The scope of this paper is the presentation of the computational methodologies applied in the comprehensive code for rotorcraft developed in the last years at Roma Tre University, along with the assessment of its prediction capabilities focused on flight conditions characterized by strong blade–vortex interactions. Boundary element method approache...
Article
This paper presents a boundary-field integral formulation suitable for the prediction of noise scattered by moving bodies. Although based on the same flow modeling assumptions, linear formulations derived from velocity potential or pressure disturbance wave equations provide different predictions when the scatterer is not at rest. Indeed, the discr...
Article
Traditional helicopter blades are subject to significant deformations, which influence control forces and moments, as well as the helicopter aeroelastic and aeroacoustic behavior. Thus, the knowledge of rotor elastic states could help improving flight control efficiency, and reducing vibration level and acoustic emissions of next-generation helicop...
Article
Wake inflow modelling is a crucial issue in the development of efficient and reliable computational tools for flight dynamics and aeroelastic analyses of rotorcraft. The aim of this work is the development of state-space, wake inflow modelling techniques for coaxial rotors perturbed from steady flight conditions, based on simulations provided by hi...
Article
With the aim of alleviating the noise annoyance emitted by blade–vortex interactions occurring on helicopter main rotors, the present work presents a methodology suitable for the identification of a multi-cyclic harmonic controller based on the actuation of rotor blades equipped with Miniature Trailing Edge Effectors. The objective of the control m...
Conference Paper
Aim of this paper is the assessment of pressure-based integral formulations for the prediction of noise scattered by moving bodies. Specifically, a scattering modeling based on the Ffowcs Williams and Hawkings Equation is herein proposed and its capability in capturing the main features of noise field scattered by moving bodies is investigated. Two...
Conference Paper
Full-text available
Rotor wake inflow plays a crucial role in rotorcraft aeromechanics and, on the other side, it is strictly dependent on the operating condition. The presence of the ground below the rotor disc affects rotor aerodynamics, especially through the modification of wake inflow with respect to free-air operative condition. Here, the effect of ground on wak...
Conference Paper
Full-text available
This paper deals the activities conducted in the GARTEUR Action Group HC/AG-24 to address noise scattering of helicopter rotors in presence of the fuselage. The focus of the Action Group is on the development and validation of numerical prediction methods and establishing an experimental data base for numerical validations. The numerical methods ap...
Conference Paper
Full-text available
This paper presents an original combined approach to shape-sensing and structural health monitoring of helicopter rotors. It is based on the measurement of strain in a limited number of points over the blade surface. The Shape-Sensing algorithm is modal-based and capable of reconstructing nonlinear, moderate lag, flap and torsion deflections. Two S...
Conference Paper
Full-text available
The scope of this paper is the validation of the comprehensive aero-acousto-elastic solver developed in the last years at Roma Tre University against the well-known HART II database, which is the outcome of an international EU-US cooperative research project consisting of a wind tunnel experimental campaign for the measurements of loads, blade defl...
Article
Full-text available
A novel N th order finite element for interior acoustics and structural dynamics is presented, with N arbitrarily large. The element is based upon a three-dimensional extension of the Coons patch technique, which combines high-order Lagrange and Hermite interpolation schemes. Numerical applications are presented, which include the evaluation of the...
Conference Paper
This paper deals the activities conducted in the GARTEUR Action Group HC/AG-24 to address noise scattering of helicopter rotors in presence of the fuselage. The focus of the Action Group is on the development and validation of numerical prediction methods and establishing an experimental data base for numerical validations. The numerical methods ap...
Article
Full-text available
This paper presents the development and the application on helicopter blades of a measurement system based on FBG strain gauges. Here, the main goal is the structural characterization of the main rotor blades, with the aim of showing the potentialities of such a system in blades quality check applications, as well as in the development of structura...
Conference Paper
Full-text available
The effect of dynamic inflow modeling on helicopter aeromechanic simulations for stability, response and control purposes is investigated. Two different linear time-invariant inflow models, extracted from high-fidelity aerodynamic simulations, are presented and applied. One provides the wake inflow as a function of rotor kinematic variables, while...
Conference Paper
The aim of this paper is the introduction and the assessment of integral formulations suited for the prediction of noise scattered by moving bodies. In particular, acoustic pressure formulations based on the Lighthill equation are presented, and their capability to capture the influence of scatterer motion on the scattered field is examined. Both b...
Article
This paper investigates different methodologies for the evaluation of the acoustic disturbance emitted by helicopter’s main rotors during unsteady maneuvers. Nowadays, the simulation of noise emitted by helicopters is of great interest to designers, both for the assessment of the acoustic impact of helicopter flight on communities and for the ident...
Conference Paper
This paper presents an original combined approach to shape-sensing and structural health monitoring of helicopter rotors. It is based on the measurement of strain in a limited number of points over the blade surface. The Shape-Sensing algorithm is modal-based and capable of reconstructing nonlinear, moderate lag, flap and torsion deflections. Two S...
Conference Paper
Rotor dynamic wake inflow modeling is one of the main issues in the development of efficient and reliable tools for design and flight dynamic simulation of rotorcraft. In general, it is affected by the operating condition (hovering, advancing, steady or maneuvering flight), but the interference with external obstacles might play a crucial role, esp...
Chapter
Aeroelasticity of PrandtlPlane configurations is a yet unexplored field. The overconstrained structural system and the mutual aerodynamic interference of the wings enhance the complexity of the aeroelastic response. In this work the aeroelastic behavior of several models based on wing system of 250-seat PrandtlPlane design is studied. When an alumi...
Article
The aim of this work is the development of dynamic, finite-state modelling of wake inflow generated by kinematic perturbations of rotors in steady flight conditions. Extracted from responses of high-fidelity aerodynamic solvers, it is suited for flight dynamics applications. A three-step identification procedure is proposed: (1) evaluation by a hig...
Conference Paper
Full-text available
This paper presents the development of a linear, finite-state, dynamic perturbation model for wake inflow of coaxial rotors in arbitrary steady flight, based on high-accuracy radial and azimuthal representations. It might conveniently be applied in combination with blade element formulations for rotor aeroelastic modelling, where three-dimensional,...
Conference Paper
Main and tail rotors are major sources of noise for helicopters and contribute significantly to ground noise footprint. The main research effort in the past was concentrated on the noise generation mechanism and its reduction. Even though the scattering of noise generated by helicopter rotors has been recognized to deeply affect noise spectrum and...
Article
Among the several sources of acoustic annoyance produced by rotorcraft in operating conditions, blade-vortex interactions (BVIs) capture the interest of much of the current research. This paper deals with the reduction of BVI noise from helicopter main rotors by application of the active twist rotor concept (ATR), exploiting smart materials for twi...
Article
This paper deals with an efficient computational process for the synthesis of a low-frequency controller aimed at alleviating helicopter rotor blade–vortex interaction noise. It is based on an optimal, multicyclic, control approach that exploits distributed torque loads actuated by smart materials to twist rotor blades at the 2/rev frequency (activ...
Article
This paper presents an aeroacoustic compact-source formulation for predicting tonal noise generated aerodynamically by rotors that is applicable to hydroacoustic problems as well. Based on the knowledge of blade sectional loads, it is suitable for reducing the amount of aerodynamic data required (particularly relevant, for instance, in maneuvering...
Research
Full-text available
Dynamic wake inflow modelling is one of the main issues in the development of efficient and high-fidelity simulation tools for design of new generation rotorcraft. The aim of this paper is the development of a LTI, space-accurate, finite- state model for the prediction of dynamic wake inflow perturbations of helicopter rotors in arbitrary steady fl...
Article
This paper deals with the use of photogrammetry for the experimental identification of structural and inertial properties of helicopter rotor blades4. The identification procedure is based upon theoretical/numerical algorithms for the evaluation of mass and flexural stiffness distributions which are an extension of those proposed in the past by Lar...
Article
Full-text available
Boundary Element Method (BEM) is a widely used technique for the aerodynamic analysis of lifting bodies, due to the good compromise between fidelity and computational costs. This is especially true in rotorcraft applications, where the effects of the rotor wake play a crucial role in the evaluation of aerodynamic loads, and CFD solvers suffer for d...