Rotary-wing and vehicle aerodynamics

Research focus

The Peer review has evaluated this group as Average

Large scale wind-tunnel testing. Thanks to the strong, historical, relationship between DIA and AgustaWestland, one of the major rotorcraft companies in the world, the main research activity in this area focuses on the investigation of rotary wing aerodynamics. Specifically, work has been conducted on the characterization of the unsteady wake of a model rotor by means of the triple hot film measurement technique, the mapping of the turbulent wake of an isolated rotorcraft fuselage, and the measuring of the flow interference in front of a rotor in forward flight. Another research focus is related to sport vehicle aerodynamics. The main research activities in this field have been conducted for cycling time trials, including frame and handlebar optimization in collaboration with industrial partners, luge, where the impact of vest material on drag has been investigated following an interest by the Italian Winter Sports Federation (FISI), and endurance car prototypes (Shell Eco Marathon), where the optimal cover configuration with respect to drag reduction has been studied. Measurement techniques for highly-unsteady flows. The research has primarily investigated the threecomponent turbulent velocity vector measurement by means of triple hot wire and hot film probes, and highly unsteady pressure measurement techniques. When dealing with triple constant temperature anemometer probes, sensor mutual interference becomes an important issue. In particular, in triple hot film probes where sensor diameter is of order of 0.1 mm, the effect of sensor interference on directional response of the probe and on turbulence measurement can become quite large and has to be taken into account. Investigations were conducted in order to devise new accurate and efficient calibration methods and for establishing correct procedures when interpreting turbulent flow measurement data. In collaboration with the Dipartimento di Energetica, Politecnico di Milano, a low-pressure shock tube facility has been used to devise a novel methodology for the calibration of fast-response pressure probes for highly unsteady flows, which allowed for the determination of the transfer function of new pressure probes and to extend their operating range beyond the resonance frequency of the line-cavity system. Numerical methods for rotary-wing aerodynamics with applications. The flow around helicopter rotor blades in forward flight is unsteady and characterized by strong nonlinear and three dimensional effects, transonic regions near the tip of advancing blades, regions of shock induced separations and dynamic stall at retreating blades. In addition, the blades shed complex vortical wakes which strongly affect the operating characteristics of the rotor. To study such complex flow fields, an extensive experimental program funded by AgustaWestland has been carried out to investigate main and tail rotor aerodynamics in the Large Wind Tunnel, both in hover and forward flight conditions. To supplement the experimental investigations, a multi-block structured numerical method with overset grid capability (Chimera method) has been continuously developed. The resulting code, named ROSITA (Rotorcraft Solver ITAly) is an evolution of the common European EROS solver developed from 1996 to 1999 in the framework of the EROS program funded by the European Commission. The ROSITA code has recently enabled the first simulation of a complete rotor-fuselage configuration that has been carried out in Italy. Navier-Stokes predictions obtained with the ROSITA code will be soon be compared with the experimental measurements of a complete helicopter configuration gathered during the ongoing European project GOAHEAD. In parallel, an activity is under way that foresees the employment of unstructured grids for helicopter aerodynamics. In the first phase, such an activity has focused on the development of novel grid generation and adaptation methods in complex three-dimensional geometries, and on procedures for the deformation of meshes for fluid-structure interaction problems. High-speed trains. An activity on the numerical simulation of the flow induced by high-speed trains in tunnel networks has been underway for several years. The use of simple but accurate one-dimensional models has allowed for the simulation of train crossing in complex tunnel networks, thermal effects and smoke diffusion in fire conditions, and has been recently coupled with the prediction of sound waves at the tunnel portals.

Dipartimento di afferenza

Dipartimento di Ingegneria Aerospaziale

Docenti afferenti

Arturo Baron (Full Professor)
Marco Borri (Full Professor)
Carlo Luigi Bottasso (Associate Professor)
Sergio De Ponte (Associate Professor)
Luigi Vigevano (Associate Professor)
Franco Auteri (Assistant Professor)
Giampiero Bindolino (Assistant Professor)
Maurizio Boffadossi (Assistant Professor)
Giuseppe Gibertini (Assistant Professor)