Wyniki wyszukiwania - BazTech

Ograniczanie wyników

3 2003

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: numerical calcutation

Sortuj według:

Ogranicz wyniki do:

Performance of an air-air ejector: an attempt at numerical modelling

Sobieski W.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

2003

Vol. 7, No 3

449-457

The paper describes a numerical attempt to model the operation of an air-air ejector by means of a commercial numerical code. The obtained results are compared with the results of a laboratory experiment - particularly in relation to the diffuser of the modelled ejector. The substantial discrepancies between the performance characteristics obtained in the laboratory experiment and by numerical modelling are interpreted as a result of the absence of appropriate models of turbulence and mixing in the numerical code used. The paper also presents additional numerical simulations that emphasize the importance of unsteady phenomena (bifurcations of working fluid jet, turbulent mixing at the boundary of components) in the modelling of ejector equipment.

On numerical calculation of acoustic field of plane source

Leble S., Sukhov A.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

2003

Vol. 7, No 2

185-198

The harmonics of an acoustic beam have been evaluated numerically by means of an integral representation according to the perturbation theory. A method for evaluation of the integrals of a rapidly oscillating function has been applied. Special attention has been paid to the accuracy of calculations and an algorithm for error estimation has been proposed. A computer program has been realized, and the profiles of the first and the second harmonics have been plotted. The used methods can be applied for the problem with dissipation or dispersion.

Recharge of Gdańsk municipal groundwater intakes on the Vistula Delta Plain (Northern Poland)

Szpakowski W.

Geological Quarterly

2003

Vol. 47, No 4

389-396

Results of the Vistula Delta Plain Quaternary recharge analysis are presented in this paper. This region is situated south of Gdańsk city near the Bay of Gdańsk. There are two municipal intakes situated on the Vistula Delta Plain: Lipce and Grodza Kamienna. Different exploitation of the municipal intakes is considered. The numerical calculations are made for the pre- 1969 period before the Lipce intake started discharging the Quaternary aquifer in the steady-state conditions and for the 15 years period after the opening of the Lipce intake, in the transient conditions. The results of calculations of the natural state of the Vistula Delta Plain Quaternary aquifer are also presented. The numerical calculations were carried out using the Modflow and Modpath code in Groundwater Modelling System (GMS 2.1) package. Presented results of numerical calculations show that the Quaternary aquifer exploited by groundwater intakes Lipce and Grodza Kamienna is connected with inflow from the Martwa Wisła River into the Vistula Delta Plain Quaternary aquifer and confirm the Quaternary aquifer groundwater flow evaluation based on Cl– ions concentration in the observation wells.