In the article the influence of different materials and modified material properties of liquid mixtures on heat transfer characteristics in the natural convection mode was studied. Parametric analysis show, that the presence of particles influences heat conditions inside the thermal boundary layer, and consequently influence also overall heat transfer intensity from wall to fluid.
COBISS.SI-ID: 14341654
In this paper a numerical scheme for simulation of flow of viscous fluids is presented. Governing equations are written in velocity-vorticity formulation. Integral form of the equations is derived using the boundary element method with the aid of fundamental solutions and the Green's clause. After discretization an over-determined system of linear equations is formed. An iterative nonlinear algorithm is used to find the solution. The validity of derivation and the accuracy of the scheme is confirmed by comparing benchmark test cases with published reference data.
COBISS.SI-ID: 14208022
The final phase of the development of method for measuring the velocities of particles in a shot-blasting chamber is presented. New method for analyzing the signals was developed. Signal averaging respecting the rotational speed of rotor was applied. The averaged signal represents only one rotor revolution, thus disturbances caused by vibration transfer or/and stochastic side sensor impacts were well filtered. Cross correlation was applied again which gained the accuracy and sensitivity. The sensitivity improvement enabled the detection of sensor system inclination and its correction.
COBISS.SI-ID: 14192150
Attention is focused on the properties which significantly influence the injection, the diesel engine characteristics and subsequently the exhaust emissions. Physical and chemical properties of biodiesel and ethanol-biodiesel blends have been measured according to the requirements and test methods. Cold weather properties are improved by adding ethanol to biodiesel. In general, the results show that ethanol in biodiesel influences beneficially the most important fuel properties of the blended fuel. Potentially, this may offer a possibility to improve engine characteristics.
COBISS.SI-ID: 13959190
Cavitating flows can be modelled with different methods. One consists of using the RANS equations and an additional transport equation for the liquid volume fraction. Three cavitation mass transfer models are compared in study. Models share the common feature of employing empirical coefficients, for condensation and evaporation control. In order to compare the mass transfer models fairly, the empirical coefficients of the different models are first well tuned using an optimization strategy. The resulting mass transfer models are then compared considering the flow around the NACA hydrofoils.
COBISS.SI-ID: 00000000