Pubblicazioni per 2020

Sailboat Keel Optimization

Giovanni Lombardi, Marco Maganzi

2020

CUBIT S.c.ar.l., University of Pisa

Abstract

High-level sport serves as a powerful driver for research, particularly in the fields of aerodynamics and hydrodynamics. This work presents a multi-level optimization methodology for sailboat keels, aimed at reducing hydrodynamic drag during racing conditions.

The optimization strategy consists of two complementary phases. In the first phase, a two-dimensional optimization defines the optimal fin section profile using Bezier curves parameterized with 8 design variables. This process employs modeFRONTIER as the optimization platform, Matlab for workflow management, and X-Foil for aerodynamic analysis. In the second phase, a three-dimensional optimization determines the complete fin-bulb system geometry through 21 design parameters with a constraint on bulb volume. Three-dimensional CFD simulations were performed using StarCCM+ on an HPC cluster with 1024 cores, while parametric CAD modeling was carried out in CATIA V5.

The objective function balances performance across different sailing points: F_obj = 0.4·Cd_downwind + 0.6·Cd_upwind, assigning greater weight to upwind conditions, which are typically more critical for overall racing performance.

Authors: G. Lombardi, M. Maganzi

Conference/Journal: International CAE Conference 2020

Keywords: CFD, optimization, sailboat, keel, hydrodynamics, modeFRONTIER

Active Aerodynamics to Increase the Features of a Motorcycle

Giovanni Lombardi, Marco Maganzi, Pasqualetto Elena

2020

Cubit, Università di Pisa

Abstract

ADAMo (Adaptive Digital Aerodynamics for Motorcycles) is a research project guided by Piaggio S.p.A and partially funded by the Toscana region. The objective was to increase the performance, safety and comfort of a motorcycle by using active aerodynamics devices.

The paper describes the aerodynamics development, which was essentially based on intensive CFD use (STAR CCM+ code), related to the choice of the active devices and their optimization. Grids with about 100 million cells were used for preliminary evaluations and final verifications; for analysis of aerodynamic devices and optimization, grids with about 40 million cells were used.

There is an increase in lateral force and in both roll and yawing moments, resulting in a gain in lateral stability. There is also a significant decrease in turbulence. The mean turbulence value decreased by about 30% compared to the reference configuration, while the maximum value decreased more than 40% (in the zone of the driver legs). CFD results were verified in a wind tunnel, with differences less than 5% on the global values.

Conference/Journal: Proceedings of 20. Internationales Stuttgarter Symposium, Springer Vieweg

DOI/Source: https://link.springer.com/chapter/10.1007/978-3-658-29943-9_14

Keywords: CFD, Motorcycle aerodynamics, Active devices, ADAMo, Piaggio

Springer Verlag ISBN 978-3-658-29942-2