The presented paper investigates two methods of heat transfer problem in nanoscale.Simulations are takeover thin metal film irradiated by the ultrashort laser pulse.The first simulation is based on the Boltzmann transport equation and solved using the lattice Boltzmann method.The second applied method was the finite difference method with a two-temperature model.Results of both simulations were compared with experimental data what is presented in Calculations.

The article presents the one-dimensional numerical modelling of heat transfer in thin metal films irradiated by ultra-short laser pulses. In the mathematical description the relaxation times and the boundary conditions for phonons and electrons are given as interval numbers. The direct problem has been solved by means of the in-terval lattice Boltzmann method using the rules of directed interval arithmetic, while at the stage of the inverse problem solution, the evolutionary algorithm is applied. On the stage of inverse problems investigations, the evolutionary algorithm coupled with the interval lattice Boltzmann method is used.

In the paper a description of heat transfer in a one-dimensional metal films is considered. The Boltzmann transport equation and a two-temperature model supplemented by appropriate boundary and initial conditions are applied to analyze the thermal process in a heated thin metal film. The problem considered is solved by the lattice Boltzmann method and the finite difference method respectively. The internal heat source is given in two different ways. In the first way, the internal heat source is considered a constant value, while in the second way an exponential function which simulates irradiation using a laser pulse is used. In the final part of the paper numerical examples of comparison of two methods and conclusions are presented.

The paper presents the description of numerical modelling of heat transfer proceeding in metals in nano scale. The mathematical model of the problem analyzed is based on the interval coupled lattice Boltzmann equations for electrons and phonons supplemented by the boundary-initial conditions. The first, second and periodic type boundary conditions have been assumed. In this model, the standard two-dimensional 9-speed lattice (D2Q9) is used. The main concept behind this work was to use the directed interval arithmetic to analyze the thermal processes with the uncertain parameters. Moreover the periodic boundary conditions have been introduced to deal with the situation where heat transport takes place in a region with a large ratio of the length to the width. In the final part of the paper the numerical examples of two-dimensional heat transfer analysis are shown.

The paper concerns axial water turbine of power equal to 1 kW. The example of axial water turbine constructional calculations was provided, as well as turbine rotor construction with NACA profile blades. The laboratory test rig designed and built to perform measurements on pico turbine was described. The turbine drove three-phase electrical generator. On the basis of highest efficiency parameters, pico turbine basic characteristics were elaborated. The experimental research results indicated that pico turbine can achieve maximum efficiency close to the values of larger water turbines.

The article presents static calculation of an automatic machine for unloading of rotor axial forces in a high-pressure and high-speed pump. Analysis of the rotor displacement influence to values of mass flow rate and pressure in the unloading chamber of the unloading system is given. The main geometric parameters of the system are obtained.

In the paper it is described a schema of typical pump system and it is shown its static and dynamic characteristics which are essential in the process of computerization measurements of the characteristics. Compurized test stand for operational measurements has been presented. The article describes the basic static and dynamic characteristics of a centrifugal pump and pipeline Software aiding measurements make possible to determine pump parameters on the basis of measured physical quantities. Test-stand is labour-saving for measurements, description of cavitational development curves and determination of cavitational pump characteristics. Elaborated measurement card makes possible to compare working point with catalogue parameters. Rys. 1. Schemat układu pompowego

The paper presents new construction of sub- mersible pump, which obtains high efficiency thanks to original solutions of flow channels. The submersible pump has several safety devices which turn off electric engine in explained situ- ations and protect against next damages. The paper includes an analysis of various parameters of pump's work, which trans- gression could become a danger for submersible pump. In case of the danger the security system turns off the engine tempo- rally or permanently. 1. Gorniczy zatapialny agregat pompowy Przyklad konstrukcji gorniczego zatapialnego agregatu pom­ powego, zwanego tez krocej gorniczą pompą zatapialną, przed­ stawiono na rys. 1. Zastosowanie chlodzenia silnika elektrycz­ nego plaszczem wodnym pozwala w temperaturze otoczenia na znaczne przekroczenie jego mocy nominalnej, określonej dla pracy przy chlodzeniu powietrzem o temperaturze 25°C. Zasadniczą cechą konstrukcyjną, stanowiącą o mozliwości dopuszczenia takiego agregatu do pracy w kopalniach, są tzw. szczeliny ogniowe, odgradzające komore silnika od jego oto­ czenia. Gornicza pompa zatapialna nowej konstrukcji posiada ory­

There had been considered axial vibration of the rotor equipped with an automatic balancing system for axial forces. There were constructed amplitude and phase frequency characteristics, as well as evaluated influence of inertial resistance into throttling channels of auto discharge system. There were identified damping properties of resistance devices.

Rozwoj infrastruktury, szczegolnie wiejskiej, pociągnąl za sobą budowe sieci wodociągowych, czego konsekwencją jest wzrost ilości ściekow. Niestety rozwoj kanalizacji, szczegolnie sanitarnej i oczyszczalni ściekow, nie nadąza za zwiekszającymi sie potrzebami ich odprowadzania. Dlatego konieczne są dalsze inwestycje i optymalizacje stosowanych konstrukcji pomp i projektow przepompowni. W problematyce ciśnieniowego transportu ściekow mozna wyroznic: z l zjawisko przeplywu ściekow przewodami rurowymi i charakterystyki rurociągow; z l zasady dzialania, konstrukcje i charakterystyki pomp do ściekow; z

This paper presents an application of the wavelet theory to function approximation and to approximate solutions of chosen differential equations. There are considered the functions of class L(R) and the first and the second order linear differential equations in interval [0, 1] with appropriate boundary conditions. Haar wavelet and linear B-spline wavelet were applied to approximate these functions and solving these problem.

The paper describes numerical and experimental study of centrifugal pump developed to assist left ventricle of the human heart. Usage of the modern computer software provides wide possibilities of studying complicated flow processes and visualization of the obtained results. The numerical pump model, based on theoretical study, was developed in Solid Edge. The mesh of the pump flow tract for numerical calculation was made in CFX-Mesh and ICEM CFD. The numerical calculations of the steady fluid flow in the centrifugal pump were performed to define the characteristics of the pump operating parameters at various flow rates. The construction of centrifugal pump flow tract was analyzed using Computational Fluid Dynamics (CFD) methods. Modifications of the geometry of flow tract were made by pump’s constructors. Changes concerned the pump flow analyses obtained from the numerical calculations. Dangerous areas in the flow, where the level of the shear stress achieved the maximal values, were defined. The character of the fluid flow in different parts of the pump was investigated. To perform the experimental validation of pump characteristics a laboratory stand was made. A series of measurements was performed to obtain pump performance characteristics. A comparison of the numerical calculation results and experimental measurements has shown differences between achieved results.