Volume 11, number 2 (2017)
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Item Double diffusive magnetohydrodynamic squeezing flow of nanofluid between two parallel disks with slip and temperature jump boundary conditions(University of West Bohemia, 2017) Sobamowo, Gbeminiyi Musibau; Akinshilo, A. T.In this paper, double diffusive squeezing unsteady flow of electrically conducting nanofluid between two parallel disks under slip and temperature jump condition is analyzed using the homotopy perturbationmethod. The obtained solutions from the analysis are used to investigate the effects of the of Brownian motion parameter, thermophoresis parameter,Hartmann number,Lewis number and pressure gradient parameters, slip and temperature jump boundary conditions on the behavior of the nanofluid. Also, the results of the homotopy perturbation method are compared to the results in the literature and good agreements are established. This study is significant to the advancements of nanofluidics such as energy conservation, friction reduction and micro mixing biological samples.
Item MHD mixed flow of unsteady convection with radiation over a vertical porous plate: Lie group symmetry analysis(University of West Bohemia, 2017) Rajput, Govind R; Patil, V. S.; Jadhav, B. P.In this paper, we study the magnetohydrodynamic (MHD) mixed unsteady flow over a vertical porous plate. The system of non-linear partial differential equations governing the physical model is transformed into a system of non-linear ordinary differential equations via Lie group analysis. Using the Runge-Kutta fourth order method along with shooting technique the numerical analysis is carried out to study the effect of associated parameters on the velocity, temperature and concentration distribution. Computed results for the velocity, temperature and concentration distribution are discussed graphically.Item Virtual hybrid human body model for PTW safety assessment(University of West Bohemia, 2017) Hynčík, Luděk; Bońkowski, Tomasz; Vychytil, JanRoad traffic accidents cause one of the highest numbers of severe injuries. The numbers of deaths and seriously injured citizens prove that traffic accidents and their consequences are still a serious problem to be solved. Virtual human body models play an important role to assess injuries during impact loading especially for scenarios, where complex dynamical loading is taken into account. The most suffering group is so called vulnerable road users (VRU) like powered two-wheelers (PTW) riders. The presented work contributes to increasing safety of PTW riders by implementing virtual human body model for injury risk analysis. The scalable hybrid virtual human body model Virthuman, which was formerly developed, validated and demonstrated in impact scenarios, is improved by updated neck and shoulder models in order to describe the realistic kinematics during complex long duration impact loading and presented in the oblique impact scenario compared to the THUMS results.Item Leather for motorcyclist garments: Multi-test based material model fitting in terms of Ogden parameters(University of West Bohemia, 2017) Bońkowski, Tomasz; Šoltés, Lukáš; Hynčík, Luděk; Kottner, Radek; Kochová, PetraThis paper is focused on experimental testing and modeling of genuine leather used for a motorcycle personal protective equipment. Simulations of powered two wheelers (PTW) accidents are usually performed using human body models (HBM) for the injury assessment equipped only with the helmet model. However, the kinematics of the PTW rider during a real accident is disturbed by the stiffness of his suit, which is normally not taken into account during the reconstruction or simulation of the accident scenario. The material model proposed in this paper can be used in numerical simulations of crash scenarios that include the effect of motorcyclist rider garment. The fitting procedure was conducted on 2 sets of samples: 5 uniaxial samples and 5 biaxial samples. The experimental characteristics were used to obtain the set of 25 constitutive material models in terms of Ogden parameters.Item Numerical investigation of heat and mass transfer processes in the combustion chamber of industrial power plant boiler. Part 1, Flow field, temperature distribution, chemical energy distribution(University of West Bohemia, 2017) Askarova, Aliya; Maximov, Valeriy; Bolegenova, Saltanat; Bolegenova, Symbat; Yergaliyeva, Aigul; Šafařík, PavelIn the present paper, the furnace chamber of the BKZ-160 boiler ofAlmaty TPP-3 (Kazakhstan) has been calculated. The thermal characteristics of the process were studied in the form of the distribution of temperature fields and chemical energy, and the aerodynamics of the combustion chamber was also calculated. The type of fuel, its elementary and fractional composition, exerts the greatest influence on the course of heat-mass exchange processes and aerodynamics. The computational experiment was carried out with two models of particle size distribution: a polydisperse fuel flame (the particle diameter varies from 10 to 120 μm) and monodisperse fuel flame (particle size identical and equal to dp = 60 μm). Based on the results of the computational experiments, the main regularities in the distribution of heat fluxes in the combustion chamber volume and flow aerodynamicswere obtained. It is shown that the greatest thermal load falls on the central region of the walls of the combustion chamber and the location of the burner devices, which is typical for both mono- and polydisperse fuel flames. The temperature data obtained as a result of the computational experiment showed better convergence with the empirical data obtained directly at TPP-3. Aerodynamics of the flow for the two selected models of particle size distribution has insignificant differences, but how they affect other characteristics of the process is one of the following tasks in view of the authors. It should be noted that the calculation of the polydisperse fuel flame takes much more calculation time.
