The use of complex fluids is one of the modern techniques used in small devices in order to enhance their thermal performance. This paper is a numerical study of a complex fluid imprisoned in a chamber with two hot bodies exposed to a magnetic field of constant intensity. The upper and lower walls move horizontally at a constant velocity, while the lateral sides are thermally insulated. The numerical simulation of the system was achieved based on the finite volume method that solves the differential equations of fluid mechanics and heat transfer. Simulations were carried out under the following conditions: Re = 1 to 40, Ri = 0 to 100, n = 0.6 to 1.4 and Ha = 0 to 100. The study showed that the thermal activity of the two bodies is different and related to initial condition. Also, the effect of the magnetic field is strong in the case of shear-thinning fluids, while its effect is diminished in the case of shear-thickening fluids.

The paper presents various examples of the application of the PAK software and its modules for thermal, filtration, and stress–strain analysis of different complex engineering structures such as gravity dams, arch dams, embankment dams, tunnels, and mines. Examples of research, studies, and projects in which PAK has been applied to assess the condition of various structures are provided. Special emphasis is placed on the application of PAK for modeling thermal, filtration, and stress–strain processes at the gravity dam, Iron Gate I Dam, and the arch dam, Grančarevo. PAK has been successfully used for a long time on these structures as part of the Dam Safety Management System, providing the basis for various analyses and reports on the assessment of dam condition and safety.

Dynamic analysis of engineering structures is essential in the design process, providing insights into their behavior under various loading conditions. This paper focuses on the comparative study of implicit and explicit dynamic analysis methods using the PAK software and FEMAP with the Nastran software. Both methods have distinct advantages and disadvantages, which are examined in detail through the simulations of simple examples. The influence of the solution methods on the results is critically analyzed, offering valuable insights into selecting the appropriate dynamic analysis technique. The results from PAK software are validated through comparison with FEMAP with Nastran software, highlighting the accuracy of both software in dynamic analysis.