The energy efficiency of machines is nowadays an intensively studied problem. The efficiency of the induction motor is dominantly influenced by the rotor’s and stator winding’s temperature. The main goal of the research presented in this paper is to develop a methodology based on Computational Fluid Dynamics (CFD) analysis of internal and external aerodynamics, which is necessary for the optimisation of cooling of the induction motors. In this paper, the theoretical, as well as the numerical study of the internal and external aerodynamics of the induction motor, is described and verified by the experimental measurements. In the CFD-based numerical study, the Reynolds-averaged Navier–Stokes (RANS) turbulence modelling approach was applied to the flow field simulations inside and outside the induction motor. The complexity of the solved problem is increased not only by the geometric asymmetry but also by the flow’s asymmetric character caused by the fan’s rotation to cool the motor casing. This increases demand, especially on computational resources, as it is impossible to create a simplified numerical model incorporating symmetry. The volume flow of the cooling air and velocity between ribs was measured for the experimental study. Comparing the results of the Computational Fluid Dynamics (CFD) simulations and data obtained from the experimental measurement, we concluded that the results of CFD simulations are in good relationship with the results of experimental measurement and analytical approximations. An experimentally validated CFD model of the induction motor, the so-called digital twin, will be in the future used for virtual optimisation of the new designs concerning minimising losses and maximising efficiency, respectively.
This paper describes the acceleration of the most computationally intensive kernels of the Blender rendering engine, Blender Cycles, using Intel Many Integrated Core architecture (MIC). The proposed parallelization, which uses OpenMP technology, also improves the performance of the rendering engine when running on multi-core CPUs and multi-socket servers. Although the GPU acceleration is already implemented in Cycles, its functionality is limited. Our proposed implementation for MIC architecture contains all features of the engine with improved performance. The paper presents performance evaluation for three architectures: multi-socket server, server with MIC (Intel Xeon Phi 5100p) accelerator and server with GPU accelerator (NVIDIA Tesla K20m).
The objective of this work is to replace laboratory testing of cranial orthosis design with virtual prototyping. The stiffness of cranial orthosis will be evaluated by means of numerical modelling and simulation and will replace the necessity of physical testing of each and every new design of cranial orthosis to ensure its proper behaviour. In this paper we present development and validation of the numerical model as well as testing of the virtual prototyping approach using simplified model for purpose of design of the 3D printed cranial orthoses.
1 November 2019 in Strojnícky časopis - Journal of Mechanical Engineering
The paper deals with the simulation of cooling processes of the aluminium profiles inside the water quench. Cooling of profile surfaces is performed by water spray, which is created by mixing a water and an air in a nozzles. Formulas were found in literature, modified and applied to a given problem that significantly simplified a solution. The task of numerical simulations was to determine temperature and velocity profile on aluminium profile surfaces for establishing of the heat transfer coefficient which was used as the convective boundary condition necessary to solve the heat transfer in the aluminium profile by finite element method. The difference between FEM and CFD results is up to 10%.