The aim of this paper is to derive an equation for the temperature distribution in journal bearing oil film, in order to predict the thermal load of a bearing. This is very important for the prevention of critical regimes in a bearing operation. To achieve the goal, a partial differential equation of the temperature field was first derived, starting from the energy equation coupled with the Reynolds equation of hydrodynamic lubrication for a short bearing of symmetric geometry. Then, by solving the equation analytically, the function of temperature distribution in the bearing oil film has been obtained. The solution is applied to the journal bearing, for which the experimental data are available in the references. Finally, the obtained results have been compared to the corresponding experimental values for two operating regimes, and a good level of agreement was achieved.

The subject of this paper is modeling of an intake manifold of a four-stroke IC engine using contemporary software tools. Virtual 3D CAD model of an intake manifold was designed based on a real intake manifold of a four-stroke IC engine. Based on the CAD model a 3D CFD model of the intake manifold was created. The modeling has been done with the purpose of simulation of the air flow inside the intake manifold in order to monitor values of the internal pressure during several seconds of the engine operation in three different operating points. Also, an experiment was conducted, which included measurements of intake manifold pressure in the same engine operating points in the course of a time interval of approximately the same duration. The results of both the simulation and the experimental measurements have been shown in the paper proving that the created model was good enough for the intended purpose.

The paper outlines the development and optimization of an aerodynamic device for a semi-trailer truck model to reduce aerodynamic drag force. The optimization procedure involves the selection of a basic aerodynamic device shape, using airfoil profiles, and refining its shape and position through established optimization techniques like Full Factorial Design and Response Surface Method within the Design of Experiments framework. The test subject is a 1:10 scale model of the semi-trailer truck. To validate the results obtained from the Computational Fluid Dynamics (CFD) simulations, experimental measurements of aerodynamic drag forces were performed in a wind tunnel. This combination of simulation and experimental testing ensures the reliability and effectiveness of the optimization process for improving vehicle aerodynamics.

The paper describes the concept of a new internal combustion engine. Presented IC engine concept possesses a variable displacement, variable compression ratio, combustion at constant volume, improved intake and exhaust processes, as well as more complete expansion of the working fluid. A comparison of some performance of this new concept with conventional IC engine and electric motors is provided. The results indicate that the performance of IC engine can still be improved. The achieved efficiency of the engine is over 40%. The Ricardo Wave program was used for simulating the characteristics of the engine. CAD model of concept engine was made with CATIA V5.