The bachelor´s thesis deals with numerical modelling of energy losses in pipes in 3D. It shows the process of creation of mathematical model, used mathematical equations and numerical methods of their solution. The theory is applied on the creation of pipe model and their energy losses with using different turbulent models.

Diploma thesis is focused on computational modelling of aerodynamic noise of flow past a solid body. Computation of flow around a cylinder is performed for different meshes and time steps in initial part of the thesis. Results from every computation are compared. Computation aerodynamic noise due to flow around a cylinder is simulated in other part of diploma thesis. In the second benchmark computation, turbulent models have to be considered, because flow with high Reynolds number is turbulent. Computation is based on two different ways: acoustic analogy and direct method. A few different turbulent models is described and is analyzed influence to modelling aerodynamic noise. The results and knowledge of the benchmarks computation have been used in compu-tational modelling of aerodynamic noise of flow around simplified side view mirror. Surface (2D) and spatial (3D) simulations are performed. Based on computation modelling of aerodynamic noise of flow around simplified side view mirror has been designed new geometry, that aim is reduced aerodynamic noise and improved aerodynamic parameters.

This thesis is dealing with optimization by using artificial intelligence of an induction machine rotor slot. The one optimized is commonly manufactured induction motor with simple deep bar rotor. Goal is to design an optimization method and achieve the highest possible value of efficiency and power factor of chosen machine. Work contains the parametric model construction in Ansys Maxwell software, the optimization algorithm assembly and its setup for desirable output, and processing of the results.

This thesis deals with the problem of the high-speed electrical machines. In the introduction summary of the high-speed machines are discussed. Induction machine with squirrel cage winding and solid rotor is chosen as suitable solution for given requirements. The multiple types of designs of the induction machines with solid rotor and problematic areas are discussed. Main part of this thesis is an electromagnetic design of the machine with respect to mechanical stress. The designed machine is analyzed with the use of finite element method in ANSYS Mechanical and Maxwell software.

The aim of this semester work is to analyze the losses of induction motor, according to their measure, use programs using the finite element method for the detection of the motor and the subsequent evaluation and comparison of the results obtained. The first part deals with the general AM, losses and measure their losses. The next section is very Lossmeasurement submitted asynchronous motors. The measured two machines have different characteristics in the sheet. The following section is calculating the losses using the finite element method using ANSYS Maxwell and RMXprt.The next part is the analysis of motor losses with a different number of rotor bars. This section is addressed to the models developed and validated by measuring the actual machine.

Die FKM-Richtlinie dient dem Festigkeitsnachweis im Maschinenbau und verwandten Bereichen. Ihre Anwendung kann immer dann vereinbart werden, wenn keine spezielle Norm anzuwenden ist. Sie beschreibt die Nachweisführung für statische und zyklische Lasten an Bauteilen aus Stahl und Aluminiumwerkstoffen. Der Festigkeitsnachweis nach FKM-Richtlinie läuft stets nach dem gleichen Schema ab: -> Ermittlung der Werkstoffkennwerte -> Festlegung der Sicherheitsfaktoren -> Ermittlung der Beanspruchung -> Ermittlung des Auslastungsgrades Mit „FKM inside ANSYS“ steht dem ANSYS-Anwender ein Werkzeug zur Verfügung, das bei der richtlinienkonformen Nachweisführung unterstützt. Dabei erfolgt der Nachweis nicht geschweißter Volumenbauteile mit örtlichen Spannungen und der Nachweis geschweißter Volumenbauteile nach dem Strukturspannungskonzept. Insbesondere für zyklische Belastungen ist das Auffinden der Nachweisstellen – also der maximal beanspruchten Positionen – nicht immer trivial. Hier hilft „FKM inside ANSYS“, durch vollflächige Visualisierung des Auslastungsgrades auf den zu untersuchenden Bauteilen diese Positionen sicher zu bestimmen und zu bewerten. Es ergeben sich gegenüber einem manuellen Nachweis folgende Vorteile: -> Schnelle und einfache Definition der Nachweisparameter -> Schnelle Durchführung von Parameterstudien -> Schnelles und sicheres Auffinden der maximal beanspruchten Stellen -> Erleichterte Ergebnisinterpretation durch Visualisierung des Auslastungsgrades -> Automatische Berichterstellung an den Nachweispositionen

Every computational fluid dynamics engineer deals with a never ending story – limitedcomputer resources. In computational fluid dynamics there is practically never enoughcomputer power. Limited computer resources lead to long calculation times which result inhigh costs and one of the main reasons is that large quantity of elements are needed in acomputational mesh in order to obtain accurate and reliable results.Although there exist established meshing approaches for the Siemens 4th generation DLEburner, mesh dependency has not been fully evaluated yet. The main goal of this work istherefore to better optimize accuracy versus cell count for this particular burner intended forsimulation of air/gas mixing where eddy-viscosity based turbulence models are employed.Ansys Fluent solver was used for all simulations in this work. For time effectivisationpurposes a 30° sector model of the burner was created and validated for the meshconvergence study. No steady state solutions were found for this case therefore timedependent simulations with time statistics sampling were employed. The mesh convergencestudy has shown that a coarse computational mesh in air casing of the burner does not affectflow conditions downstream where air/gas mixing process is taking place and that a majorpart of the combustion chamber is highly mesh independent. A large reduction of cell count inthose two parts is therefore allowed. On the other hand the RPL (Rich Pilot Lean) and thepilot burner turned out to be highly mesh density dependent. The RPL and the Pilot burnerneed to have significantly more refined mesh as it has been used so far with the establishedmeshing approaches. The mesh optimization has finally shown that at least as accurate resultsof air/gas mixing results may be obtained with 3x smaller cell count. Furthermore it has beenshown that significantly more accurate results may be obtained with 60% smaller cell count aswith the established meshing approaches.A short mesh study of the Siemens 3rd generation DLE burner in ignition stage of operationwas also performed in this work. This brief study has shown that the established meshingapproach for air/gas mixing purposes is sufficient for use with Ansys Fluent solver whilecertain differences were discovered when comparing the results obtained with Ansys Fluentagainst those obtained with Ansys CFX solver. Differences between Fluent and CFX solverwere briefly discussed in this work as identical simulation set up in both solvers producedslightly different results. Furthermore the obtained results suggest that Fluent solver is lessmesh dependent as CFX solver for this particular case.

New approach for computational modeling of the dynamic behavior of elastic body immersed in incompressible viscous stagnant fluid is described in this work. It is based on determination of added effects (added mass and added damping). This effects are inserted into computational model and it replace influence of the fluid. Commonly used commercial computational software may be used. Approach is based on assumption appropriate for the linear flow. Two pressure field are determined. One for movement of the unite acceleration of the fluid boundary and the second for unite velocity. Nonlinear model (Navier-Stokes equation in ALE form) had to be used for determination of the added damping, hence results are valid only for pre-selected amplitude of vibration.

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