ELEKTROENERGETSKIH OBJEKATA COMPUTATION OF QUASISTATIC ELECTROMAGNETIC FIELDS OF COMPLEX ELECTRIC POWER FACILITIES Bojan
Trkulja, B., Štih, Ž., Proračun kvazistatičkog elektromagnetskog polja..., Energija, god. 57(2008), Br. 5., str. 580-591 Trkulja, B., Štih, Ž., Computation of Quasistatic Electromagnetic Fields ..., Energija, Vol. 57(2008), No. 5, pp. 580-591 PRORAČUN KVAZISTATIČKOG ELEKTROMAGNETSKOG POLJA SLOŽENIH ELEKTROENERGETSKIH OBJEKATA COMPUTATION OF QUASISTATIC ELECTROMAGNETIC FIELDS OF COMPLEX ELECTRIC POWER FACILITIES
Application of bicubic splines in the boundary element method
Abstract In this paper, we proposed the method for improving the accuracy of BEM, which is based on application of bicubic splines for interpolation functions. Application of bicubic splines ensures continuity of class C 1 at the boundaries of element. Such an interpolation results in smooth approximation of the surface sources leading to high accuracy of computation. Set of integral equations is solved by implementation of Galerkin method for determination of unknown coefficients.The accuracy of the proposed approach is illustrated by comparison of the solution of electric field in thin-plate capacitor by BEM using bicubic splines, second-order polynomial, linear and piecewise-constant interpolation.
Experimental Study for a Double-Glazed Forced-Flow Solar Collector/Regenerator
Experimental study of a double-glazed forced-convection solar collector/regenerator for absorption solar cooling is presented. The south facing experimental solar collector/regenerator with 10 deg slope is located at Kaohsiung, Taiwan at 120{degree}19minutesE longitude and 22{degree}34minutesN latitude. The size of the collector is 1 m wide and 7 m long with an effective regeneration area of 0.9 m by 6 m. Previous study for single-glazed forced-convection solar collector/regenerator operated at the same location has shown to have a best day-average efficiency of 17%. In order to raise the system performance, a double-glazed collector/regenerator is constructed such that air can be preheated in the upper channel flow. The preheated air is then conducted into the lower channel where it contacts with the film flow of solar heated lithium-chloride solution and regenerates the solution by carrying out the evaporated water vapor. The preheated air has lower relative humidity but the same humidity ratio since it is sensibly heated. Therefore, the regeneration driving potential is increased. The present study shows that the best day-average efficiency can reach 20% which increases the feasibility of the open-cycle absorption solar cooling system. Effects of controlling parameters on the collector/regenerator performance are studied, and heat and mass transfer correlationsmore » are also presented for design purposes.« less