Prohlížení Acta Polytechnica dle názvu

Zobrazují se záznamy 699-718 z 880

    • SIMILARITY SOLUTIONS AND CONSERVATION LAWS FOR THE BEAM EQUATIONS: A COMPLETE STUDY 

      Autor: Halder , Amlan Kanti; Paliathanasis , Andronikos; Leach , Peter Gavin Lawrence
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      We study the similarity solutions and we determine the conservation laws of various forms of beam equations, such as Euler-Bernoulli, Rayleigh and Timoshenko-Prescott. The travelling-wave reduction leads to solvable ...

    • SIMPLE MODELS OF THREE COUPLED PT -SYMMETRIC WAVE GUIDES ALLOWING FOR THIRD-ORDER EXCEPTIONAL POINTS 

      Autor: Schnabel , Jan; Cartarius , Holger; Main , Jörg; Wunner , Günter; Heiss , Walter Dieter
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2017)
      We study theoretical models of three coupled wave guides with a PT-symmetric distribution of gain and loss. A realistic matrix model is developed in terms of a three-mode expansion. By comparing with a previously postulated ...

    • SIMULATION ANALYSIS OF PREHEATER CHARGE TO THE ROTARY FURNACE 

      Autor: Mikula , Jan; Palička , Pavol; Kerekanic , Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2015)
      Mathematical modeling of heat aggregates is one of the fundamental methods of the mathematical modelling research. A mathematical model based on the method of elementary balances was created for the thermal treatment of ...

    • SIMULATION MODEL BASED ON REGIONAL DEVELOPMENT AND VIRTUAL CHANGES 

      Autor: Dlask , Petr
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2015)
      This paper reports on change as an indicator that can be provide more focused goals in studies of development. The paper offers an answer to the question: How might management gain information from a simulation model and ...

    • SIMULATION OF A MANEUVERING AIRCRAFT USING A PANEL METHOD 

      Autor: Schoř, Pavel; Kouřil, Martin; Daněk, Vladimír
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2021)
      We present a method for numerical simulations of a maneuvering aircraft, which uses a first-order unsteady panel method as the only source of aerodynamic forces and moments. By using the proposed method, it is possible to ...

    • Simulation of a Matrix Converter Fed Drive With Sliding Mode Control 

      Autor: Bauer , Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2012)
      Induction machines are among the most widely used electrical-to-mechanical converters in electric drives. Their advantageous robustness and simplicity goes hand-in-hand with complicated control. A converter with a suitable ...

    • Simulation of Free Airfoil Vibrations in Incompressible Viscous Flow — Comparison of FEM and FVM 

      Autor: Sváček , Petr; Horáček , Jaromír; Honzátko , Radek; Kozel , Karel
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2012)
      This paper deals with a numerical solution of the interaction of two-dimensional (2-D) incompressible viscous flow and a vibrating profile NACA 0012 with large amplitudes. The laminar flow is described by the Navier-Stokes ...

    • SIMULATION OF HEAT TRANSPORT AT THE COOLING OF THE SUGAR SOLUTION IN A RECUPERATION EXCHANGER 

      Autor: Brestovič , Tomáš; Čarnogurská , Mária; Příhoda , Miroslav; Kubík , Michal
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2015)
      The paper describes a mathematical model of the cooling process of a highly concentrated sugar solution in an exchanger with a specifically shaped heat exchanging surface of the cooling panels. An analysis of the individual ...

    • Simulation of laser drilling of Inconel X-750 and Ti-5Al-2.5Sn sheets using COMSOL 

      Autor: Hanon, Muammel M.; Taha, Ziad A.; Zsidai, László
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2021)
      This study aims to investigate the simulation of laser drilling processes on Inconel X-750 and Ti-5Al-2.5Sn sheets. To this end, COMSOL Multiphysics 5.2 software was employed to carry out the virtual experiments. A JK 701 ...

    • SIMULATION OF LOW-GRADE COAL COMBUSTION IN REAL CHAMBERS OF ENERGY OBJECTS 

      Autor: Askarova , Aliya; Bolegenova , Saltanat; Bolegenova , Symbat; Beketayeva , Meruyert; Maximov , Valeriy; Nugymanova , Aizhan; Šafařík , Pavel
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)
      The aim of the work is to create new computer technologies for 3D modelling of heat and mass transfer processes in high-temperature physicochemically reacting environments that will allow to determine the aerodynamics of ...

    • SIMULATION OF RADIATIVE HEAT FLUX DISTRIBUTION UNDER AN INFRARED HEAT EMITTER 

      Autor: Loufek , Jan; Královcová , Jiřina
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2015)
      The article deals with a heat radiation model used for heat flux calculation of an infrared heater. In general, we consider a system consisting of a set of objects, whereas a single object could stand for a heater, a ...

    • SIMULATION OF SURFACE HEATING FOR ARBITRARY SHAPE’S MOVING BODIES/SOURCES BY USING R-FUNCTIONS 

      Autor: Plankovskyy , Sergiy; Shypul , Olga; Tsegelnyk , Yevgen; Tryfonov , Oleg; Golovin , Ivan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)
      The purpose of this article is to propose an efficient algorithm for determining the place of an action of a heat source with a given motion law for a body of an arbitrary shape using methods of analytical geometry. The ...

    • SIMULTANEOUS FITS IN ISIS ON THE EXAMPLE OF GRO J1008–57 

      Autor: Kühnel , M.; Müller , S.; Kreykenbohm , I. Kreykenbohm; Schwarm , F.-W.; Grossberger , C.; Dauser , B. T.; Nowak , M. A.; Pottschmidt , K.; Ferrigno , C.; Rothschild , R. E.; Klochkov , D.; Staubert , R.; Wilms , J.
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2015)
      Parallel computing and steadily increasing computation speed have led to a new tool for analyzing multiple datasets and datatypes: fitting several datasets simultaneously.  With this technique, physically connected parameters ...

    • SIZE ANALYSIS OF SOLID PARTICLES AT THE EXPERIMENTAL DEVICE FOR MULTI-STAGE BIOMASS COMBUSTION 

      Autor: Hrnčířová , Michaela; Špiláček , Michal; Pospíšil , Jiří
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2014)
      This paper presents the results of an analysis of ash content particles produced in biomass combustion at an experimental device. The main parts of the device are: the water heater, the gasifying chamber, the air preheater, ...

    • SOLAR ABSORBER WITH A STRUCTURED SURFACE – A WAY TO INCREASE EFFICIENCY 

      Autor: Mrňa , Libor; Řiháček , Jan; Šarbort , Martin; Horník , Petr
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)
      The basic idea of a solar absorber’s thermal gain increase is the keyhole effect utilization during which the radiation is absorbed by multiple reflections on cavity walls. The lattice of pyramidal or conical cavities on ...

    • SPECIFIC EMISSIONS FROM BIOMASS COMBUSTION 

      Autor: Skopec , Pavel; Hrdlička , Jan; Kaválek , Michal
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2014)
      This paper deals with determining the specific emissions from the combustion of two kinds of biomass fuels in a small-scale boiler. The tested fuels were pellets made of wood and pellets made of rape plant straw. In order ...

    • SPECIFIC FEATURES OF THE OXYFUEL COMBUSTION CONDITIONS IN A BUBBLING FLUIDIZED BED 

      Autor: Skopec, Pavel; Hrdlička, Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)
      Oxyfuel combustion is a promising approach for capturing CO2 from power plants. This technology produces a flue gas with a high concentration of CO2. Our paper presents a verification of the oxyfuel combustion conditions ...

    • Spectral Analysis of Schrödinger Operators with Unusual Semiclassical Behavior 

      Autor: Exner , Pavel; Barseghyan , Diana
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      In this paper we discuss several examples of Schrödinger operators describing a particle confined to a region with thin cusp-shaped ‘channels’, given either by a potential or by a Dirichlet boundary; we focus on cases when ...

    • Spectral Singularities do not Correspond to Bound States in the Continuum 

      Autor: Mostafazadeh , Ali
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      We show that, contrary to a claim made in arXiv:1011.0645, the von Neumann-Winger bound states that lie in the continuum of the scattering states are fundamentally different from Naimark’s spectral singularities.

    • STABILITY OF BOSE-EINSTEIN CONDENSATES IN A PT-SYMMETRIC DOUBLE-δ POTENTIAL CLOSE TO BRANCH POINTS 

      Autor: Löhle, Andreas; Cartarius, Holger; Haag, Daniel; Dast, Dennis; Main, Jörg; Wunner, Günter Wunner
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2014)
      A Bose-Einstein condensate trapped in a double-well potential, where atoms are incoupled to one side and extracted from the other, can in the mean-field limit be described by the nonlinear Gross-Pitaevskii equation (GPE) ...