1,721,106 research outputs found
CFD analisys of a homogenizing valve used in dairy plants
No full textPumps Valves and system, Yogesh Jog, Indi
Un modello per la simulazione “control-oriented” di motori Diesel automobilistici
No full textAtti del Dipartimento di Ingegneria Industriale - Univ.di Parm
Gray box modeling of an excavator’s variable displacement hydraulic pump for fast simulation of excavation cycles
No full textThis paper describes the results of a study focused on the application of gray box modeling methodology on an excavator’s hydraulic pump. This modeling approach has been adapted to accelerate the control system development time for a complete excavator, while providing accurate system dynamics. This mathematical model has been developed using the bond graph methodology. The excavator is described by two models: a hydraulic model and a kinematic model; dynamic parameters are continuously calculated during an excavation cycle, providing a platform to study the pump’s behavior. The gray box model of the variable displacement pump has been validated on the basis of a set of experimental data collected on a test rig and on the field using an excavator. Herewith the results of this study are presented
Analysis and Design of Direct Steam Injection for Tomato Concentrate Sterilization
No full textDirect Steam Injection (DSI) is a sterilization technique which is often used for high viscosity fluid food when the preservation of the quality characteristics and energy efficiency are the priority.
In this work an apparatus for the sterilization of tomato concentrate has been analyzed by means of a 3D Computational Fluid Dynamics (CFD) model, in order to optimize the exchanger performance in term of temperature distribution inside the product.
A multidimensional two-phase model of steam injection inside a non-Newtonian pseudoplastic fluid was adopted to evaluate the thermal history of the product and the condensation rate of the steam injected in the heat exchanger during the thermal process.
Subsequently the CFD analysis has been extended to examine the effects of the different process parameters (sterilization temperature, steam flow rate, radial and axial temperature profiles, and nozzle geometry) on the resulting product.
Result obtained allowed to understand the effects of process parameters on the behavior of the condensing steam and obtain better performance of the exchanger in terms of temperature distribution of the threated product
Design optimization of a special relief valve with response surface methodology
No full textThis paper describes the utilize of a numerical procedure for the analysis and the optimization of an hydraulic component, namely a particular direct acting relief and anti-cavitation cartridge valve. The element taken as reference is usually connected to a hydraulic line with the aim of keeping the circuit pressure between two different set values; moreover it can work as anti-shock valve, avoiding pressure peaks.
The developed procedure is based on Response Surface Methodology techniques, adopting the path search method known as Steepest Descent. For this purpose, the valve behaviour is analytically described by means of a properly defined objective function. The procedure approximates this objective function with a simple model whose coefficients are evaluated using the predictions performed by a AMESim® model of the valve, developed in C++ language by the authors. The sets of simulations for the fitting model are planned according to Design Of Experiments techniques. The entire optimization algorithm has been developed with MATLAB® scripts, which are able to plan the simulation with the AMESim® model of the valve, automatically execute the simulations, post process the results and finally establish the optimal configuration of the component taken as reference.
The considered starting point for the optimization process is given by a stock configurations of the valve, considered also for the experimental validation of the AMESIM® model in previous works. Three different optimal configurations of the valve, for different values of the preset pressure, have been proposed, and prototypes of the new designs have been realized. Experimental investigations point out the improved performance of the proposed designs, highlighting the potentials of the developed optimization methodology
- …
