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Mass/heat transfer analogy method in the research of convective fluid flow through channels with a specific geometry

Grosicki Sebastian, Wilk Joanna

Archives of Thermodynamics

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2023

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Vol. 44, no 4

427--446

EN

The present work contains the results of the comparative analysis of the literature data and the own investigations on mass and heat transfer coefficients occurring under conditions of the convective fluid flow through channels characterised by a specific geometry. The authors focused on the available experimental investigations on mass transfer. The considered experiments were carried out using the electrochemical method named limiting current technique. Two channel geometries were discussed: the annular channel of the conventional size and the long minichannel with a square cross-section area. Taking into consideration dimensionless numbers: Schmidt and Nusselt – analogical for mass and heat transfer – the formulas describing the phenomena under consideration were included. In the case of the annular channel the laminar and turbulent range of Reynolds numbers was studied. For the square minichannel – the laminar flow is considered. The analogy between mass and heat transfer introduced by Chilton and Colburn was applied in the analysis. An equivalent boundary condition is included in considerations concerning the mass and heat transfer. It is the Dirichlet boundary condition characterised by constant temperature of the wall which corresponds to the situation of constant ion concentration at the cathode surface in the limiting current technique. The main purpose of the present work was to verify the method for the determination of heat transfer coefficients using the analogy between mass and heat transfer processes in the case of convective fluid flow through the annular and square channels. The problem discussed in the present work is important and actual due to the possibility of the elimination of temperature measurements in the investigations of heat transfer processes occurring in channels characterised by a specific geometry. It should be noted that sometimes temperature measurement may be difficult or even impossible. This situation also causes high uncertainty of the obtained results. Due to this problem, the presented analysis was performed also with the use of thermal results based on the analytical solution. The verification of the use of mass/heat transfer analogy method in specific cases gives the extended knowledge of correct application of the limiting current technique in heat transfer research. The main objective of the work was achieved by conducting a comparative analysis of the adequate mass and heat transfer results. The existing literature data do not provide an answer to the question about the correctness of using the limiting current technique in the case of discussed annular channels or long square minichannels. The received results make us be critical of applying the mass/heat transfer analogy method in some heat transfer cases.

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Forecasts an unemployment rate in Poland with time - area analogy method

Gondek A.

Management

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2010

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Vol. 14, no 1

288-296

EN

This article presents the research which aim was to construct forecasts of an unemployment rate for Poland for next few years. The time-area analogy method was use in this study and brought high credibility forecasts of the unemployment rate based on analogies between Poland and UE countries in research phenomenon.

PL

Artykuł prezentuje badanie, którego celem było skonstruowanie prognoz stopy bezrobocia w Polsce na najbliższe lata. Do postawienia wiarygodnych prognoz użyto metody analogii przestrzenno-czasowych i wykorzystano analogie w kształtowaniu się badanego zjawiska miedzy Polską a krajami UE.

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Optymalizacja siatek prętowych metodą analogii do ładunków elektrycznych

Sadowski K.

Mechanik

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2004

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R. 77, nr 11

782-783

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Technika analogii z N2O jako metoda określenia rozpuszczalności gazu w cieczy w układach z reakcją chemiczną

Kierzkowska-Pawlak H., Zarzycki R.

Inżynieria Chemiczna i Procesowa

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2004

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T. 25, z. 3/2

1101--1106

PL

Omówiono technikę analogii z N2Ojako metodę określenia rozpuszczalności gazu w cieczy w proce-sie absorpcji z reakcją chemiczną. Wykonano pomiary absorpcji N2O i CO2 w wodnych i etanolowych roztworach metylodietanofoaminy w temperaturze 293 K. Otrzymane wyniki umożliwiły weryfikację zakresu stosowalności omawianej metody.

EN

N2O analogy technique was described as the method for estimation of gas solubility in solutions when it re-B. The measurements of N2O and CO2 absorption in aqueous and ethanol solutions of methyldiethanolamine 'ere performed at 293 K. The obtained results allowed verifying the applicability rangę of the N2O analogy.

5

Metoda oceny przepływów Raszynki

Ciepielowski A., Dąbkowski S. L.

Woda-Środowisko-Obszary Wiejskie

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2003

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T. 3, z. spec. (6)

125--139

PL

W pracy omówiono warunki przyrodnicze i użytkowanie ziemi w zlewni Raszynki wpadającej do Utraty, scharakteryzowano dostępne dane hydrologiczne i sposoby ich wykorzystania w opracowaniu charakterystyk hydrologicznych. Zlewnia nie jest kontrolowana, lecz istnieją fragmentaryczne dane o stanach wody z okresu 1953–1960 i kilka pomiarów przepływu. Dane te, wraz z wynikami pomiarów własnych, wykorzystano w prezentowanych analizach. Ponadto posłużono się danymi dla profilu Krubice na Utracie, której zlewnię przyjęto jako analog w obliczaniu charakterystyk przepływu wody w Raszynce. Oceniono przepływy charakterystyczne i prawdopodobne dla profilu w Michałowicach na Raszynce (profil zamykający zlewnię o powierzchni 61,5 km²).

EN

The paper discusses natural conditions and land use in the Raszynka River (a tributary of the Utrata River) catchment area. The available hydrological data and the methods of their utilization have been characterized with a view to determining hydrological characteristics. The catchment is not monitored, there exist, however, some fragmentary data about water levels from the period of 1953–1960 as well as several discharge measurements. These data, together with the author´s own measurements, have been used in the presented analysis. Furthermore, the authors have used the data for the Krubice profile on the Utrata River whose catchment area was assumed as an analogue in calculating discharge characteristics in the Raszynka River. The characteristics and probable discharges have been estimated for the Michałowice profile on the Raszynka River, which closes the catchment area of 61.5 km².