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When the designer's target is the optimization of a composite system, the analysis of the interactions between the different elements of the system becomes a crucial topic. As a matter of fact, in some cases, the effect of these interactions can become more important than the behavior of each individual component. In the area of fluid power, this problem is very common. In particular the case of hydraulic powered transmission for mobile applications can be considered a paradigm of these problems. This paper presents an original numerical approach to study and design of a hydrostatic transmission: the target is the optimization of the system as a whole, taking into account the characterization and the interaction among all parts. First, the system and the application are presented; the attention is focused on the analysis and modeling of its hydraulic parts (pumps, motors, valves).

In order to increase the efficiency of automotive turbochargers at low speed without compromising the performance at maximum boost conditions, variable geometry compressor (VGC) systems, based on either variable inlet guide vanes or variable geometry diffusers, have been recently considered as a future design option for automotive turbochargers. This work presents a modeling, analysis and optimization study for a Diesel engine equipped with a variable geometry compressor that help understand the potentials of such technology and develop control algorithms for the VGC systems,. A cycle-averaged engine system model, validated on experimental data, is used to predict the most important variables characterizing the intake and exhaust systems (i.e., mass flow rates, pressures, temperatures) and engine performance (i.e., torque, BMEP, volumetric efficiency), in steady-state and transient conditions.

In the present work, we describe a low-cost implementation of an Active Noise Cancellation (ANC) system. The most interesting feature of our implementation is the use of general-purpose hardware, without the need of expensive and hard-to-program Digital Signal Processing (DSP) devices. In particular, the reference signals, collected with accelerometers properly placed on noise-generating parts and the error feedback signals are collected by means of an USB interface. All signal processing, aimed at primary path estimation and anti-noise audio signal generation, is performed using Simulink running on a commercial mini PC. The Exponential Sine Sweep (ESS) method is adopted for the measurement of the secondary path from the cancellation loudspeakers to the error microphones. An adaptive Filtered-X Least Mean Square (LMS) algorithm determines the anti-noise audio signal to be emitted.

Metal additive manufacturing is finding growing applicability in motorsports and high performance car sectors. Laser-Powder Bed Fusion (L-PBF) is the most developed AM technology for lightweight aluminum alloys producing near-net-shape components of complex geometry that achieve outstanding lightweight targets. A key issue in the widespread industrial acceptability of L-PBF is the structural integrity of these lightweight components when subjected to dynamic loading conditions because it requires in-depth knowledge of the fatigue behavior of L-PBF aluminum under the combined effect of stress gradients, residual stresses, surface condition and process-induced internal defects.