Andrea's Research

Monika's Research

This section provides a brief summary of the main fluid power research topics performed by Andrea Vacca’s group. Goals of the activities span from the numerical analysis of innovative components and the development of novel testing methodologies to the study of control aspects related to hydraulic systems. Studies concerning a proper modeling of fluid properties have been performed as well.
The broad research goal is to increase the performance of current fluid power systems and to give a contribution for the growth of this discipline in the engineering world. Many of the activities presented in this section were performed at Andrea Vacca’s former Dept., at the University of Parma (Italy).

External Gear Pumps/Motors

gear animated gif Various projects have been performed in the area of external gear units. Purposes of these projects are: the development of accurate simulation models; the proposal of new solutions characterized by better efficiency and lower noise emissions; the development of innovative testing techniques. More details about these project are reported here (Download PDF).

HYGESim:
The main result of the research activities in external gear machines is given by the simulation tool HYGESim. HYGESim (HYdraulic GEar machines Simulator) is a numerical model for the simulation of external spur gear pumps and motors. Conceived at University of Parma (Italy) with the sup hygesim scheme port of the company CASAPPA, HYGESim is currently developed at MAHA Fluid Power Research Center.
The simulation tool consists of different modules: a lumped parameter fluid dynamic model, a mechanical model for evaluation of the gears motion (considering also the micro motion of the gear axes of rotation) and a geometrical model. The first two models are implemented within the LMS Imagine.Lab AMESim® simulation environment, with proper submodels written in C language, while the geometrical model is implemented developing proper macros capable to read directly the CAD3D drawings of the unit (pump/motor).
The simulation tool is characterized by an accurate description of the geometry of the different components (i.e. teeth’s profile, design of sliding elements) and it is able to calculate the movements of the gears’ axes of rotation resulting from the forces exerted on both gears. Potentials of the model are represented by the prediction of the main features of flow through the machine (such as the inter-teeth meshing pressure, the evaluation of possible cavitation onsets, pulsation of flow at the external ports, etc.) and the detection of the wear of the casing due to the possible contact between the gears and the casing. The tool is currently used for the analysis of the main phenomena related to the operation of the machine, for the optimization of its design and for the research of innovative solutions.

Systems/Components Modeling

components e system modeling Various activities have been performed concerning the modeling and testing of hydraulic systems and components (with particular reference to hydraulic valves). Some exemplifying projects are reported here (Download PDF).
Concerning the valve modeling, the described projects show the capability of simulating not only the main phenomena related to the internal flow, but also the interaction between the internal parts (the mechanical elements and the electro-magnetical actuation system, if present) and between the other components present in the considered system. Moreover, the aspect related to the possible control strategies are accounted as well. In few cases, advance circuit d optimization criteria have been used to improve current designs or to formulate new solutions. All developed models were validated on the basis of experimental measurements.
For systems, the considered cases are pertinent to hydrostatic transmissions and to other hydraulic systems for mobile applications. In these cases, lumped parameters models were developed with the aim of analyzing the margin of improvements of current solutions and to design innovative systems.

Modeling of Fluid Properties

The research on fluid properties modeling is aimed to find formulations suitable to describe peculiar flow features within hydraulic components, such as the cavitation, the effect of temperature and pressure, and the presence of dissolved or non-dissolved air. The main aim is to develop formulations suitable for fast simulation models, such as lumped parameters models.