Wyniki wyszukiwania - BazTech

1

Asymptotic approximations to the distributed activation energy model for non isothermal pyrolysis of loose biomass using the weibull distribution

Dhaundiyal A., Singhb S. B.

Archivum Combustionis

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2016

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Vol. 36 nr 2

131--146

EN

This paper explains the influence of some relevant parameters to biomass pyrolysis, described by the asymptotic solution of non-isothermal nth order distributed activation energy model using the Weibull distribution. Investigated parameters are the integral range, the frequency factors, heating rate, the reaction order, and the shape, scale and location parameters of the Weibull distribution. These parameters have been used for evaluation of the kinetic parameters of the non-isothermal Weibull DAEM from thermo-analytical data of biomass pyrolysis.

2

Zastosowanie asymptotycznych funkcji bazowych do aproksymacji niestacjonarmych przebiegów temperatury

Ciałkowski M.

Zeszyty Naukowe Politechniki Poznańskiej. Maszyny Robocze i Transport

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2008

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Nr 63

27-43

PL

Nagłym procesom obciążenia cieplnego ciał stałych towarzyszą bardzo duże gradienty temperatury i w konsekwencji duże naprężenia termiczne. Uchwycenie szybkich zmian temperatury ciał stałych w takich stanach za pomocą metod numerycznego całkowania prowadzi do dużych błędów. W artykule przedstawiono metody całkowania równania przewodnictwa z funkcjami bazowymi dobrze aproksymującymi fizyczne przebiegi. Wyniki numeryczne potwierdzają skuteczność interpolacji przebiegów temperaturowych za pomocą 2- i 3-węzłowych asymptotycznych funkcji bazowych.

EN

Sudden processes of ihermal load of solids arę accompanied by high temperaturę gradi-ents and, in conseąuence, high thermal stresses. Presentalion of quick temperaturę change of a solid in such a condition with numerical integraling methods results in high errore. The paper presents a method of integrating the heat conductańce equation with base funclions well approximating the physical processes. Numerical results confirm efficiency of interpo-lation of the temperaturę patterns with the help of 2- and 3-node asymptotic base functions.

3

Asymptotic solution for laminar isothermic flow of compressible fluid between rotating surfaces of revolution

Walicka A.

International Journal of Applied Mechanics and Engineering

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2008

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Vol. 13, no 4

1101-1118

EN

A steady laminar flow of a compressible newtonian fluid is considered, in a narrow space between two surfaces of revolution, rotating with generally different angular velocities about a common axis of symmetry. The problem statement for two classes of throughflow, with full and rotational inertia, is formulated. A procedure for perturbing a creeping flow solution and an iteration scheme are developed to produce a solution for higher approximations. The solution depends on seven parameters and is asymptotic in the sense of its good convergence in the second approximation for both classes of throughflow. Results for the second class of throughflow are presented for the velocity components, the pressure and temperature distributions for typical shapes of surfaces such as disks and spherical surfaces.

4

Asymptotic solution for laminar flow of an incompressible fluid with variable viscosity and thermal conductivity between rotating surfaces of revolution

Walicka A.

International Journal of Applied Mechanics and Engineering

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2007

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Vol. 12, no 3

831-848

EN

A steady laminar flow of an incompressible Newtonian fluid with variable viscosity and thermal conductivity is considered, in a narrow space between two surfaces of revolution, rotating with generally different angular velocities about a common axis of symmetry. The problem statement for two classes of throughflow, with full and rotational inertia, is fonnulated. A procedure for perturbing a creeping flow solution and an iteration scheme are developed to produce a solution for higher approximations. The solution depends on eight or seven parameters and is asymptotic in the sense of its good convergence in the second approximation for both classes of throughflow. Results for second class of throughflow are presented for the velocity components, the pressure and the temperature distributions for typical shapes of surfaces as disks and spherical surfaces.