Feasibility Study on MHEV Application for Motorbikes: Components Sizing, Strategy Optimization through Dynamic Programming and Analysis of Possible Benefits

Reducing CO2 emissions is becoming a particularly important goal for motorcycle manufacturers. A fully electric transition still seems far away, given the difficulties in creating an electric motorcycle with an acceptable range and mass. This opens up opportunities for the application of hybrid powertrains in motorcycles. Managing mass, cost, and volume is a challenging issue for motorcycles; therefore, an MHEV architecture represents an interesting opportunity, as it is a low-complexity and low-cost solution. Firstly, in this work, an adequate sizing of the powertrain components is studied for the maximum reduction in fuel consumption. This is performed by analyzing many different system configurations with different hybridization ratios. A 1D simulation of the motorcycle traveling along the homologation cycle (WMTC) is performed, and the powerunit use strategy is optimized for each configuration using the Dynamic Programming technique. The results are analyzed in order to highlight the impact of kinetic energy recovery and engine load-point shifting on fuel consumption reduction. The results show the applicability of MHEV technology to road motorcycles, thus providing a useful tool to analyze the cost/benefit ratio of this technology. The developed methodology is also suitable for different vehicles once a specific test cycle is known

First-principle-based MD description of azobenzene molecular rods

Extensive density functional theory (DFT) calculations have been performed to develop a force field for the classical molecular dynamics (MD) simulations of various azobenzene derivatives. Besides azobenzene, we focused on a thiolated azobenzene’s molecular rod (4′-{[(1,1′-biphenyl)-4-yl]diazenyl}-(1,1′-biphenyl)-4-thiol) that has been previously demonstrated to photoisomerize from trans to cis with high yields on surfaces. The developed force field is an extension of OPLS All Atoms, and key bonding parameters are parameterized to reproduce the potential energy profiles calculated by DFT. For each of the parameterized molecule, we propose three sets of parameters: one best suited for the trans configuration, one for the cis configuration, and finally, a set able to describe both at a satisfactory degree. The quality of the derived parameters is evaluated by comparing with structural and vibrational experimental data. The developed force field opens the way to the classical MD simulations of self-assembled monolayers (SAMs) of azobenzene’s molecular rods, as well as to the quantum mechanics/molecular mechanics study of photoisomerization in SAMs

Aerodynamics characteristics of an innovative large turboprop through wind tunnel tests including propulsive effects

This paper deals with the assessment of both longitudinal and directional aerodynamic characteristics of an innovative large capacity turboprop aircraft by means of a wind tunnel test campaign on a scaled model. The aircraft under investigation is an innovative turboprop platform providing for a three lifting surface layout and a rear engine installation. The scope of this research is to deeply investigate the aerodynamic behavior of such an innovative platform to assess the aerodynamic interferences among the aircraft components. In particular, the effects of the third lifting surface (the canard), installed in front of the main wing, must be carefully investigated to have a reliable estimate of the aircraft stability and controllability characteristics. This innovative platform provides for a rear engine installation at the tip of the horizontal tailplane. Thus, a specific experimental campaign has been dedicated to investigating the aircraft aerodynamic characteristics in power on conditions

Aeroelastic wind tunnel tests of the RIBES wing model

Aeroelastic wind tunnel tests on a half-wing model have been performed at the University of Naples “Federico II” to acquire data about aerodynamic forces, section pressure coefficient, stress, strain, and model displacement, to validate high fidelity Fluid-Structure Interaction approaches based on Reynolds-Averaged Navier-Stokes and Finite Element Method solutions investigated at the University of Rome “Tor Vergata”. Most of the available experimental databases of aeroelastic measurements, performed on aircraft wings, model full scale systems, focusing primarily on aerodynamic aspects rather than on structural similitudes. To investigate flow regimes that replicate realistic operating conditions, wind tunnel test campaigns involve the generation of relative high loads on models whose safe dimensioning force the adoption of structural configurations that lose any similitude with typical wing box topologies. The objective of this work is to generate a database of loads, pressure, stress, and deformation measurements that is significant for a realistic aeronautical design problem. At this aim, a wind tunnel model of a half-wing that replicates a typical metallic wing box structure and instrumented with pressure taps and strain gages has been investigated. All experimental data and numerical models are freely available to the scientific community at the website www.ribes-project.eu

Electronic Transport in 2D-Based Printed FETs from a Multiscale Perspective

As 2D materials (2DMs) gain the research limelight as a technological option for obtaining on-demand printed low-cost integrated circuits with reduced environmental impact, theoretical methods able to provide the necessary fabrication guidelines acquire fundamental importance. Here, a multiscale modeling technique is exploited to study electronic transport in devices consisting of a printed 2DM network of flakes. The approach implements a Monte Carlo scheme to generate the flake distribution. By means of ab initio density functional theory calculations together with non equilibrium Green's functions formalism, detailed physical insights on flake-to-flake transport mechanisms are provided. This later feeds a 3D drift-diffusion and Poisson solution to compute self-consistently transport and electrostatics in the device. The method is applied to MoS2 and graphene-based dielectrically gated FETs, highlighting the impact of the structure density and variability on the mobility and sheet resistance. The prediction capability of the proposed approach is validated against electrical measurements of in-house printed graphene conductive lines as a function of film thickness, demonstrating its strong potential as a guide for future experimental activity in the field