Wyniki wyszukiwania - BazTech

1

Trefftz method for polynomial-based boundary identification in two-dimensional Laplacian problems

Hożejowski L.

Journal of Theoretical and Applied Mechanics

|

2016

|

Vol. 54 nr 3

935--944

EN

The paper addresses a two-dimensional boundary identification (reconstruction) problem in steady-state heat conduction. Having found the solution to the Laplace equation by superpositioning T-complete functions, the unknown boundary of a plane region is approximated by polynomials of an increasing degree. The provided examples indicate that sufficient accuracy can be obtained with a use of polynomials of a relatively low degree, which allows avoidance of large systems of nonlinear equations. Numerical simulations for assessing the performance of the proposed algorithm show better than 1% accuracy after a few iterations and very low sensitivity to small data errors.

2

Trefftz method for an inverse geometry problem in steady-state heat conduction

Hożejowski L.

Journal of Applied Mathematics and Computational Mechanics

|

2016

|

Vol. 15, nr 2

41--52

EN

The paper addresses a boundary identification problem in two-dimensional steady-state heat conduction. The proposed approach based on the Trefftz method allows one to reconstruct the unknown part of a regular domain boundary from the given temperature measurements on it, provided that both the temperature and heat flux on the remaining part of the boundary are known. The reconstruction of an unknown boundary is done through successive approximations with a polynomial or a truncated Fourier series. The proposed solution method, whose merit lies in the avoidance of large systems of nonlinear equations, is fast converging, accurate and numerically stable, as demonstrated in the included numerical examples.

3

Analiza błędów przy wyznaczaniu współczynnika przyjmowania ciepła przy przepływie cieczy w minikanale

Hożejowska S., Hożejowski L.

Inżynieria i Aparatura Chemiczna

|

2009

|

Nr 6

85-87

PL

W pracy przedstawiono metodę wyznaczania współczynnika przejmowania ciepła między wrzącą cieczą przepływającą przez minikanał a folią grzewczą w oparciu o pomiary temperatury metodą termografii ciekłokrystalicznej. Celem pracy jest zastosowanie rachunku wyrównawczego dla zminimalizowania błędów identyfikacji współczynnika przejmowania ciepła. Jest to możliwe dzięki szacunkowej znajomości błędów pomiarowych.

EN

A method for determination of heat take-up coefficient between boiling liquid flowing through a minichannel and heating foil on basis of temperature measurements using the liquid crystal thermography is presented in the paper. The aim of this work was to apply adjustment calculus for the minimization of identification errors of heat take-up coefficient. This is possible thanks to estimation of measurement errors.

4

Wyznaczanie lokalnego współczynnika przejmowania ciepła w badaniach wymiany ciepła w minikanale

Piasecka M., Hożejowska S., Hożejowski L., Poniewski M. E.

Inżynieria i Aparatura Chemiczna

|

2006

|

Nr 6s

190-191

EN

The paper presents the determination of local heat transfer coefficients between the heating foil and boiling refrigerant flowing through a minichannel. Different mathematical models, one-and two-dimensional, were proposed for the heat flow phenomenon observed. A comparative analysis dealing with the obtained coefficient values was conducted. The values mentioned depended on the way the issue is considered and on adopted methods for its solution.