Search results

1

Modelling of nitrogen oxides formation applying dimensional analysis

100%

Čarnogurská M., Příhoda M., Brestovič T.

Chemical and Process Engineering

|

2011

|

vol. 32

|

issue 3

175-184

EN

The article presents the procedure for how to establish a mathematical model of nitrogen oxides formation based on the theory of dimensional analysis. The model is based on selected physical quantities (parameters) measurable during regular operation of a heat generation plant. The objective of using dimensional analysis to describe nitrogen oxides formation is to show that between operating parameters of the combustion equipment and the NOx formation there is a significant correlation.The obtained results, which are further described in this article, have proved this fact. The obtained formula expressing nitrogen oxides formation, based on dimensional analysis, applies universally to any boiler fuelled by coal, gas or biomass. However, it is necessary to find C, m, n constants for the formula by experiment, individually for each type of boiler and used fuel. The experiment is based on on-line measurements of selected operational parameters for a given boiler, combusting a certain type of fuel with its actual moisture content and calorific value. The methodology, described in this article, helps to find relationships between the operational parameters and the formation of NOx emissions for a particular furnace. The developed mathematical model has been validated with boilers fuelled by black coal and biomass. Both the results obtained from direct measurements of NOx in both types of boilers, and the results obtained by calculation using equation based on the dimensional analysis, are in a very good accord. When burning coal, the variation between NOx expression from the model and the on-line measurements ranges between -12.23 % and + 9.92 %, and for burning biomass between -0.54 % and 0.48 %.The intention of the authors is to inform the professional community about the suitability of the dimensional analysis to describe any phenomena for which there is currently no exact mathematical formulation based on differential equations or empirical formulas. Many other examples of dimensional analysis applications in practice may be found in the work of Čarnogurská and Příhoda (2011).

2

Cellular-automata based modeling of heterogeneous biofilm growth for microbiological processes with various kinetic models

100%

Skoneczny S., Skoneczny S.

Chemical and Process Engineering

|

2019

|

vol. 40

|

issue 2

3

Mathematical Modelling of the Infusion Test

100%

Cieslicki K.

Polish Journal of Medical Physics And Engineering

|

2007

|

vol. 13

|

issue 1

33-54

EN

The objective of this paper was to improve the well established in clinical practice Marmarou model for intracranial volume-pressure compensation by adding the pulsatile components. It was demonstrated that complicated pulsation and growth in intracranial pressure during infusion test could be successfully modeled by the relatively simple analytical expression derived in this paper. The CSF dynamics were tested in 25 patients with clinical symptoms of hydrocephalus. Basing on the frequency spectrum of the patient's baseline pressure and identified parameters of CSF dynamic, for each patient an "ideal" infusion test curve free from artefacts and slow waves was simulated. The degree of correlation between simulated and real curves obtained from clinical observations gave insight into the adequacy of assumptions of Marmarou model. The proposed method of infusion tests analysis designates more exactly the value of the reference pressure, which is usually treated as a secondary and of uncertain significance. The properly identified value of the reference pressure decides on the degree of pulsation amplitude growth during IT, as well as on the value of elastance coefficient. The artificially generated tests with various pulsation components were also applied to examine the correctness of the used algorithm of identification of the original Marmarou model parameters.

4

Identification of unmeasured variables in the set of model constraints of the data reconciliation in a power unit

100%

Szega M., Nowak G. T.

Archives of Thermodynamics

|

2013

|

issue 4

5

Mathematical Modeling and Numerical Simulations of Javelin Throw

100%

Maryniak J., Ładyżyńska-Kozdraś E., Golińska E.

Human Movement

|

2009

|

vol. 10

|

issue 1

16-20

EN

A physical model of the human-javelin system has been developed together with a mathematical model of javelin flight including its transverse elastic vibrations. Three kinds of parametric identifications were distinguished: geometrical, mass and aerodynamic. Numerical calculations were made for different initial velocities and throwing angles. The results obtained have been presented graphically.

6

Modeling of adsorption phenomena in porous materials of carbonaceous origin by employing multilayer clustering based adsorption model (uniBET) with various variants of geometrical and energetical heterogeneities

100%

Ziółkowska M. R., Milewska-Duda J., Duda J. T.

Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia

|

2016

|

vol. 71

|

issue 1

EN

Multilayer clustering based adsorption model (uniBET) is aimed at adsorption phenomena modeling with having regard to surface geometrical and energetical heterogeneities. Facilitation of the uniBET model formulas leads to the LBET class models. A review on uniBET model and the analysis of the multilayer heterogeneous adsorption models for characterization of porous materials of carbonaceous origin are presented.

7

Modelling of nitrogen oxides formation applying dimensional analysis

100%

Čarnogurská M., Příhoda M., Brestovič T.

Chemical and Process Engineering

|

2011

|

issue 3

8

Steady state characteristics of a three-phase fluidized bed bioreactor with partial biomass recirculation

88%

Skoneczny S., Tabiś B., Skoneczny S., Tabiś B.

Chemical and Process Engineering

|

2019

|

vol. 40

|

issue 1

9

Thermodynamic analysis of biofuels as fuels for high temperature fuel cells

88%

Milewski J., Bujalski W., Lewandowski J.

Archives of Thermodynamics

|

2012

|

issue 4

10

The recommendations for territorial development of land use in the region

88%

Mamonov K., Kondrashenko E., Radzinskaya Y., Myronenko M., Mamonov K., Kondrashenko E., Radzinskaya Y., Myronenko M.

Geodesy and Cartography

|

2020

|

vol. 69

|

issue 1

11

Mathematical modeling of ethanol production by Saccharomyces cerevisiae in batch culture with non-structured model

88%

Konopacka A., Konopacki M., Kordas M., Rakoczy R.

Chemical and Process Engineering

|

2019

|

vol. 40

|

issue 3

12

Modeling of ethylbenzene dehydrogenation in catalytic membrane reactor with porous membrane

88%

Shelepova E. V., Vedyagin A. A., Mishakov I. V., Noskov A. S.

Catalysis for Sustainable Energy

|

2014

|

vol. 2

|

issue 1

EN

The modeling of ethylbenzene dehydrogenation in a catalytic membrane reactor has been carried out for porous membrane by means of two-dimensional, non-isothermal stationary mathematical model. A mathematical model of the catalytic membrane reactor was applied, in order to study the effects of transport properties of the porous membrane on process performance. The performed modeling of the heat and mass transfer processes within the porous membrane, allowed us to estimate the efficiency of its use in membrane reactors, in comparison with a dense membrane (with additional oxidation of the hydrogen in shell side). The use of a porous ceramic membrane was found to cause an increase of the ethylbenzene conversion at 600°C, up to 93 %, while the conversion in the case of conventional reactor was 67%. In this work, we defined the key parameter values of porous membrane (pore diameter and thickness) for ethylbenzene dehydrogenation in catalytic membrane reactor, at which the highest conversion of ethylbenzene and styrene selectivity can be reached.

13

Experimental modeling of the milling process of aluminum alloys used in the aerospace industry

75%

Țîțu A. M., Pop A. B., Nabiałek M., Dragomir C. C., Sandu A. V., Țîțu A. M., Pop A. B., Nabiałek M., Dragomir C. C., Sandu A. V.

Bulletin of the Polish Academy of Sciences: Technical Sciences

|

2021

14

Steady-state time-periodic finite element analysis of a brushless DC motor drive considering motion

75%

Jagieła M., Gwoźdź J.

Archives of Electrical Engineering

|

2015

|

vol. 64

|

issue 3

Refine search results

Modelling of nitrogen oxides formation applying dimensional analysis

Cellular-automata based modeling of heterogeneous biofilm growth for microbiological processes with various kinetic models

Mathematical Modelling of the Infusion Test

Identification of unmeasured variables in the set of model constraints of the data reconciliation in a power unit

Mathematical Modeling and Numerical Simulations of Javelin Throw

Modeling of adsorption phenomena in porous materials of carbonaceous origin by employing multilayer clustering based adsorption model (uniBET) with various variants of geometrical and energetical heterogeneities

Modelling of nitrogen oxides formation applying dimensional analysis

Steady state characteristics of a three-phase fluidized bed bioreactor with partial biomass recirculation

Thermodynamic analysis of biofuels as fuels for high temperature fuel cells

The recommendations for territorial development of land use in the region

Mathematical modeling of ethanol production by Saccharomyces cerevisiae in batch culture with non-structured model

Modeling of ethylbenzene dehydrogenation in catalytic membrane reactor with porous membrane

Experimental modeling of the milling process of aluminum alloys used in the aerospace industry

Steady-state time-periodic finite element analysis of a brushless DC motor drive considering motion