Pubblicazioni per CUBIT S.c.ar.l.

DrATC+: A Divide et Impera Extension to Trust-Based Dynamic Routing

Davide Ferraris, Letizia Russo, Lorenzo Monti

2025

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

Abstract

Trust is a critical yet often overlooked factor in network routing, especially in decentralized and dynamic environments such as IoT and ad-hoc networks. The DrATC algorithm addressed this gap by incorporating a comprehensive set of trust characteristics into dynamic routing decisions. In this paper, we propose DrATC+, an extension of the original model that applies the divide et impera (divide and conquer) principle to trust-based routing. DrATC+ enhances resilience and security by splitting messages into segments and routing them through multiple trusted paths, selected based on composite trust evaluations. We present the design and operational workflow of the algorithm, supported by evaluation scenarios. Our results demonstrate that DrATC+ can improve fault tolerance and mitigate the impact of malicious nodes adapting effectively to changing trust conditions. This work lays the foundation for more robust and adaptive trust-aware routing protocols in future networked systems.

Authors: Davide Ferraris, Letizia Russo, Lorenzo Monti

Conference/Journal: Security and Trust Management (STM 2025), Lecture Notes in Computer Science, vol 16137, Springer

Keywords: Trust, Network, Routing, IoT, Security

DOI: https://doi.org/10.1007/978-3-032-06155-3_7

Optimization of Sandblasting Gun

Emanuele Grasso, Giovanni Lombardi, Marco Maganzi

2021

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

Abstract

The use of CFD and optimization cycles is becoming fundamental for saving time and reducing design costs in industrial applications where fluid dynamics plays a critical role. This work presents a CFD-based optimization methodology for sandblasting gun geometry, aimed at maximizing output velocity and media supply rate.

The optimization strategy employed a two-phase approach. First, a preliminary validation of the numerical method was performed against experimental tests on the reference configuration, achieving satisfying agreement. The optimization cycle was then executed considering only the air flow, with the best configurations subsequently verified through Discrete Element Method (DEM) simulations including material injection.

The gun geometry was parameterized using 21 design variables. The optimization workflow integrated modeFRONTIER as the optimization platform, Matlab for workflow management, CATIA V5 for parametric CAD modeling, and StarCCM+ for CFD simulations. The dual objectives were to maximize both the output velocity and the mass flow rate of the media supply tube.

The optimization process explored 4,364 geometric configurations, of which 1,421 were valid and 1,274 showed improvement over the reference design. The three best configurations—optimized for highest output velocity, highest sand supply, and best compromise between both parameters—were validated through complete DEM simulations, confirming the effectiveness of the optimization approach.

Authors: E. Grasso, G. Lombardi, M. Maganzi

Conference/Journal: International CAE Conference 2021

Keywords: CFD, optimization, sandblasting, DEM, modeFRONTIER, StarCCM+

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

Compressible Boundary Layers: Evaluation of Predictive Methods by Means of CFD Analysis

Maganzi M., Polito L.

2017

CUBIT S.c.ar.l.

Abstract

The work concerns plane flows around wing sections at high free stream Mach numbers, limited by the validity of the assumptions that specific heats and Prandtl number are constant. The results of the evaluation by means of a commercial CFD code of simple predictive methods for skin friction, recovery temperature and heat flux at the wall with compressible boundary layer are presented for two wing section shapes, typical for supersonic flows: a rhomboidal shape with all laminar and all turbulent boundary layer flow conditions, with four thermal boundary conditions at free stream Mach number 1.5 and 2; a lenticular shape with laminar boundary layer flow and adiabatic wall conditions, at free stream Mach number 2. The results of this evaluation seem to contain interesting indications to evaluate CFD capability and to develop new investigations concerning predictive methods.

Authors: M. Maganzi, L. Polito

Conference/Journal: AIDAA XXIV International Conference, 18-22 September 2017, Palermo – Enna (Italy)

Keywords: boundary-layer, supersonic flow, predictive methods, CFD