Renata Gnatowska

Numerical analysis of wind flow and erosion in flow around the bump terrain

This research work concerns analysis of impact of wind oscillation on material erosion in flow around the corrugated substrate. Range of the work includes identification of ground specially exposed on erosion process, and estimation of blowing stream of material basing on available theoretical models. Conducted analysis is based on data concerning the characteristics of the surface of blowing object.

Modeling of Thermal Cycle CI Engine with Multi-Stage Fuel Injection

This work presents a complete thermal cycle modeling of a four-stroke diesel engine with a three-dimensional simulation program CFD AVL Fire. The object of the simulation was the S320 Andoria engine. The purpose of the study was to determine the effect of fuel dose distribution on selected parameters of the combustion process. As a result of the modeling, time spatial pressure distributions, rate of pressure increase, heat release rate and NO and soot emission were obtained for 3 injection strategies: no division, one pilot dose and one main dose and two pilot doses and one main dose. It has been found that the use of pilot doses on the one hand reduces engine hardness and lowers NO emissions and on the other hand, increases soot emissions.

Numerical analysis of heat transfer around 2D circular cylinder in pulsation inflow

This paper presents the numerical model of the measuring stand - the wind tunnel, in which is fixed the cylinder with cooling inlet oscillating stream. The aim of this work is the juxtaposition and comparison of characteristic values concerning the oscillating turbulent flow around cylinder, obtained from the experiment conducted in the wind tunnel at the Institute of Thermal Machinery, Czestochowa University of Technology with the data obtained as a result of numerical modeling of unsteady flow phenomena with heat transfer processes. Model discussed in this paper was created using a commercial program ANSYS FLUENT, that is used for mathematical modeling of flow and heat transfer processes. The expected outcome of this study is that it is possible in a way that doesn’t require large expenditures of time, numerical modeling a similar stand, which greatly facilitated by further research into the very large issue of unsteady flows.

Impact analysis performance injection in polymer composites processing shrinkage

The results of examination of influence injection moulding parameter: pressure, temperature, velocity in shrinkage convert of composite PA/PP compounds with glass fibre were presented. The influence of heat treatment in shrinkage convert was also specified.

Numeric modelling of the temperature distribution of moulded piece in the simulation of injection molding process

The article shows result of analysis of the flow of polymer materials during the filling the mould. The major objective was estimate the impact thermal conditions on the temperature distribution of moulded piece with variable thickness. Computer program Cadmould 3D by SIMCON was used for simulation of the injection moulding process which was carried out with various parameters of conversion: mould temperature and temperature of injection moulding process. The distribution of the temperature was presented in the moulded piece. A cooling system and its parameters was designed based on enabled documentation of the injection mold as well as thermostatic mould form used. The results of numerical calculation allowed the registration of temperature changes in cooling phase of the moulded piece made of semi-crystalline and amorphous polymer materials.

An analysis of incoming wind pulsation on the wind erosionprocesses on a hill

the present analysis undertakes the problem of surface wind over topography. the main focus is placed upon the effect of oncoming wind oscillations on the velocity field structure around a single sinusoidal shaped 2D hill. Additional effort has been undertaken to recognize the inflow gust influence on the surface shear stress related to the mechanism of wind induced erosion. numerical simulations have been performed through the use of the phase-averaged form of RNG version of k-ɛ turbulence model. Experimental verification of numerical data has been done in wind tunnels equipped with devices generating unsteady wind boundary layers. The main findings of the simulations reveal: a strong dependence between the characteristics of inflow periodicity and the structure of vortices of the separation region; the mean position of the reattachment point; the phase averaged velocity field; skin friction variability downstream from the hill. The results have significant implications for the prediction of sand transport in unsteady winds.