A. Bartosik

Kielce University of Technology · Department of Production Engineering

The paper deals with fully developed steady turbulent flow of slurry in a circular straight and smooth pipe. The Kaolin slurry consists of very fine solid particles, so the solid particles concentration, and density, and viscosity are assumed to be constant across the pipe. The mathematical model is based on the time averaged momentum equation. The...

The paper deals with the mathematical modelling of fully developed turbu- lent flow of a Bingham hydromixture in a pipe. The mathematical model is based on time averaged Navier-Stokes equations and uses the apparent viscosity concept. The problem of closure of the turbulence stress tensor was solved by the two-equation turbulence model in which a m...

Pressure gradients have been measured for vertical flows of slurries of particles with diameters between 1.37 and 3.4 mm in pipes of diameter 26 and 40 mm. By expressing the wall shear stress as the sum of fluid and particle components, the wall stresses for the particles have been evaluated. The stresses increase with particle diameter and density...

The paper deals with a solid-liquid turbulent flow with moderate and high solids concentration, which appears widely in chemical and mining industries. The slurry transported through a straight pipe contains medium solid particles of averaged diameters higher than 0.1 mm and lower than 0.8 mm surrounded by water as a carrier liquid. Mathematical mo...

The study deals with experiments and predictions on turbulent flow and heat exchange in a fully developed slurry flow in a vertical upward pipe. Four slurries were considered: two with glass spheres particles with diameters of 0.125 mm and 0.240 mm, respectively, and two with sand spheres particles with diameters of 0.470 mm and 0.780 mm, respectiv...

Scientists continuously are looking for new methods that allow them to better understand the flow and heat transfer phenomena [...]

Some suspensions in nature have a complex structure and demonstrate a yield shear stress and a non-linear relationship between the shear rate and the shear stress. Kaolin clay suspension is such an example in engineering, whereas in nature it is blood. This study represents an innovative approach to simulate bioliquid flow, similar to that of blood...

The article deals with the transportation of lime slurry from the reservoir to a settler in a chosen industrial enterprise. The slurry is non-Newtonian and viscoplastic. Such a slurry emphasises high viscosity and is difficult to transport under a high solid concentration in a pipeline. The amount of specially designed deflocculant was developed on...

The study deals with the modelling and experiments of vertical solid-liquid turbulent flow with narrowly sized solid particles of average diameters equal to 0.125 mm, 0.240 mm and 0.470 mm, and solid concentrations by volume from 10% to 40%, called medium slurry. The physical model assumes that the slurry with solid particles surrounded by water is...

The growing worldwide costs of energy produced as a result of conventional fuel combustion, the limited capacity of the distribution grid, and the growing number of unstable installations based on renewable energy sources increase the need to implement systems of stabilization and regulate loads for end users. The battery energy storage system (BES...

The capacity limitations of distribution networks, the increasing demands for electricity installation in terms of electricity quality parameters, and the development of electromobility all increase the need to implement systems in order to stabilize and regulate loads for end users. Battery Energy Storage Systems (BESSs), that operate in internal...

The paper contains a summary of successful invited papers addressed to the Special Issue on ‘Numerical Heat Transfer and Fluid Flow’, which were published in 2021 in the scientific journal ‘Energies’ [...]

Slurry flows commonly appear in the transport of minerals from a mine to the processing site or from the deep ocean to the surface level. The process of heat transfer in solid-liquid flow is especially important for the long pipeline distance. The paper is focused on the numerical modelling and simulation of heat transfer in a fine dispersive slurr...

In the era of growing competitiveness on the labor market, it has become common for students and graduates of higher education institutions to participate in various types of training courses and obtain various types of certificates, which are an additional asset when applying for employment. The interaction of a university with the environment req...

The paper deals with nozzle valve characteristics used in modern portable device, named handy shower, dedicated for personal hygiene. Such device significantly reduces water consumption and can be easily and quickly changed into a shower, sink or bidet. Importance of such device continuously rises as some regions and cities face water shortages. Th...

Measurements of blood rheology indicate that human blood has a yield shear stress. Transport of oxygen in the aorta or a vein depends on blood flow rate. Therefore, it is interesting to find out how blood yield shear stress affects blood transportation if flow is turbulent. The majority of mathematical approaches deal with laminar flow of human blo...

The paper presents validation of a mathematical model describing the friction factor by comparing the predicted and measured results in a broad range of solid concentrations and mean particle diameters. Three different types of solids, surrounded by water as a carrier liquid, namely Canasphere, PVC, and Sand were used with solids density from 1045...

Blood flow rate is a crucial factor in transporting an oxygen and depends on several parameters like heart pressure, blood properties like density and viscosity, frictional loss and diameter and shape of vein. Frictional loss is a main challenge of current engineering. Therefore, simulation of dependence of blood properties on frictional loss is ve...

Abstract The paper presents experimental studies on influence of two arbitrary chosen additives on wall shear stress in hydromixture, which consists solid particles of averaged diameter 0.05 mm. Experiments were performed for two mass concentration of solids equal to 20% and 43%. Measurements were performed for varied doses of deflocculants in thre...

Labour market of young people in the European community is becoming more and more competitive. This requires changes in university priorities in order to build a system enhancing entrepreneurial attitudes among students. Knowledge, skills and competencies are the main three pillars of educational process at the university. However, all of them requ...

The paper deals with the numerical simulation of mass and heat exchange in turbulent flow of solid-liquid mixture in the range of averaged solid particle diameter from 0.10mm to 0.80mm, named further as the medium slurry. Physical model assumes that dispersed phase is fully suspended and a turbulent flow is hydro-dynamically, and thermally develope...

Solid-liquid flow commonly exists in nature and in engineering and its modeling is one of the main challenges of Computational Fluid Dynamics. The paper deals with numerical simulation of mass and heat transfer in turbulent flow of Kaolin slurry. The physical model assumes that solid particles are sufficiently small and fully suspended, and a turbu...

Transport, Spedition and Logistics (TSL) are considered to be one of the main services markets of the Polish economy. The relationship between the development of the national economy and the development of the TSL services market is due to the fact that TSL is a carrier of the economy. Globalization, the development of information and communication...

During the combustion of coal in the combined heat and power plant (CHP), a very large amount of combustion waste, called further as a fly-ash, is produced. It is typical that fly-ash appears during the combustion process of the fine coal and is transported by a pipeline with support of water as a carrier liquid to a pond storage site, where it is...

Limestone slurry appears in the lime production process as the result of rinsing the processed material. It consists of particles with diameter smaller than 2 mm and the water that is a carrier of solid fraction. Slurry is directed to the settling tank, where the solid phase sediments and the excess water through the transfer system is recovered fo...

Mathematical model and predictions of solid-liquid turbulent flow with medium particles and high solids concentration, which appears widely in chemical and mining industry, is presented. Physical model assumes that slurry is flowing through a straight pipe and contains solid particles surrounded by water as a carrier liquid. Averaged solid particle...

Solid-liquid turbulent flow in a pipeline has been simulated for concentration of solids ranging from 0 to 45 % by volume. Water was the carrier liquid, the solid phase constituted fine particles with mean particle diameters of tens of microns. Mathematical model comprising the time averaged momentum equation, k-ε turbulence model with a modified t...

The paper concerns simulation of fully developed and axially-symmetrical turbulent flow of coarse-dispersive slurry if all solid particles have similar size and shape with particles diameter from 1 mm to 5 mm, solid density from 1045 kg/m 3 to 3000 kg/m 3 , and solid concentration by volume from 20% to 40%. The author examines the influence of part...

Adding of solid particles or bubbles to the carrier liquid can modify the laminar-turbulent transition. Fine particles enhance the effective viscosity of the slurry and this may be expected to delay the transition to turbulence. The paper presents experimental data of slurry flow of fine particles with the mean particle diameter of 10 μn in horizon...

Turbulent flow of a fine dispersive hydromixture with yield stress occurs frequently in chemical engineering and mineral industry. The paper deals with fully developed, axially symmetrical turbulent flow of fine dispersive hydromixture in a horizontal pipe. The mathematical model consists of the time-averaged Navier-Stokes equation in which turbule...

Bingham hydromixture with d50=0.01 mm is studied medium. Focus of attention is directed toward measurements and predictions of velocity distribution in horizontal pipe of 50 mm ID in moderate range of solid concentration. Results of numerical predictions, using modified model of turbulence with aid of Wilson-Thomas hypothesis, are matched with own...

The paper presents experimental data of slurry flow in horizontal pipe. Kaolin slurry with mean particles diameter of 10 μm was investigated. Rheological data allowed to assume that the slurry can be treated as a Bingham fluid. The main aim of the paper is to compare measured slurry velocity distribution with prediction of modified turbulence model...

The Bagnold hypothesis has been used to construct a mathematical model for fully developed turbulent slurry flow in a vertical pipe. In the mathematical model the total shear stress is modelled as the sum of liquid-wall and particle-wall stresses. The particle-wall stress is described by a modified Bagnold function. Predictions of frictional headlo...

The performance of a standard (k-L) turbulence model for predicting slurry pipeline pressure gradients is examined using experimental measurements of velocity and solids concentration distribution for upward vertical flows. Assuming the solids concentration rises abruptly from a value of zero at the pipe wall over a distance corresponding to one ha...

The unsuitabllity of a continuum model for turbulent flow of solid-liquid mixtures has been demonstrated by a number of experimental studies which employed industrial slurries and a wide range of pipe diameters. However effective particle sizes and slurry viscosities are difficult to define for such mixtures. Using spherical glass particles of medi...

The paper deals with fully developed turbulent flow of incompressible Newtonian fluid in a circular pipe. The mathematical model is based on ensemble-averaged Reynolds equations in which the turblent shear stress is designed by means of the Boussinesq hypothesis. The problem of closure is solved by using a low-Reynolds number turbulence model. In t...

Four low-Reynolds-number turbulence models are studied to investigate the fully developed pulsating turbulent flow of an incompressible Newtonian fluid in a circular pipe. In these models, the Reynolds stress is related to the local velocity gradient by the turbulent viscosity, and the turbulent viscosity is determined using modeled transport equat...