https://repositorio.ufu.br/handle/123456789/5146 2026-04-21T03:47:10Z 2026-04-21T03:47:10Z https://repositorio.ufu.br/handle/123456789/48633 2026-04-16T06:18:30Z 2025-08-21T00:00:00Z

Title: Modelling and analysis of fluid flow problems coupled with radiative heat transfer Abstract: Combustion plays a fundamental role in society, being one of the primary means of energy conversion and storage, with countless applications. As such, it is a key topic in engineering and industrial processes. In many cases, combustion and thermal radiation occur simultaneously: the high temperatures resulting from exothermic reactions, as well as the radiative interaction of the gases generated from these reactions, create an environment where complex radiative heat transfer takes place. Therefore, coupling CFD with radiative heat transfer models is essential for the accurate simulation of industrial reactive flows. Furthermore, literature shows that thermal radiation can significantly affect heat transfer in other situations, such as in thermal cavities at ambient temperature, a problem that is frequently studied without considering radiation effects. This work presents the development and benchmarking of a coupling between a CFD software (MFSim) and a radiative heat transfer solver for participating media (RTS), both internally developed by MFLab in the Federal University of Uberlândia. MFSim is a robust simulation package, capable of modelling turbulence, heat transfer, fluid–structure interactions, reacting flows, and Lagrangian particle transport. RTS is capable of modelling radiative transfer in gray and non-gray participating media containing gases like CO2 and H2O, as well as isotropic and anisotropic scattering phenomena. By integrating these codes, the extensive set of physical models available in MFSim, designed to simulate complex engineering problems, now includes radiative heat transfer, enabling more realistic and accurate modelling of combustion processes. The coupling employs distinct meshes for CFD and radiation, connected via interpolation, allowing for more computational efficiency, as radiative models do not usually require the same spatial resolution as CFD. Tests have shown that the interpolation layer between both algorithms has relatively low computational cost. Benchmarks performed on canonical cases show good agreement with the literature, verifying the approach and reinforcing the importance of radiation in heat transfer simulations.

2025-08-21T00:00:00Z https://repositorio.ufu.br/handle/123456789/48629 2026-04-10T17:44:41Z 2026-03-23T00:00:00Z

Title: Memorial para Promoção à Classe de Professor Titular Abstract: This report describes the professional career of Professor Odenir de Almeida. The document was written based on CONDIR Resolution 2017-03 of the Federal University of Uberlândia (UFU) and begins with the professor's commencement of his Mechanical Engineering studies at the Faculty of Engineering of Ilha Solteira – FEIS/UNESP in 1994. It then moves on to his master's and doctoral qualifications. Following this, a summary of his experience in Aeronautical Engineering is presented, describing his activities at the Brazilian Aeronautics Company – EMBRAER S.A., which served as a reference for his academic work. As a professor at the Federal University of Uberlândia in 2010, the most relevant activities he has carried out over the past 16 years are reported, described in four main groups: teaching, research, extension, and administration and/or management. Finally, a summary of the professor's bibliographic, technical, and academic production is presented. It is expected that, by reading this document, it will be possible to verify the relevance of the aforementioned professor's professional trajectory throughout the sixteen years he was involved in higher education (undergraduate, master's, doctorate, and teaching).

2026-03-23T00:00:00Z https://repositorio.ufu.br/handle/123456789/48591 2026-04-01T06:18:45Z 2024-02-29T00:00:00Z

Title: Dispositivo de resistência vibratório para treinamento muscular de membros inferiores Abstract: The practice of sports and physical exercise in general has a major influence on people’s fitness and quality of life. In this context, it is of fundamental importance to develop low-cost muscle training/rehabilitation equipment that is efficient and accessible. The aim of this study was to design, build and test a extension/flexion machine with a cam-spring resistance system and a device for applying mechanical vibration in the direction of muscle shortening. Two identical conventional extension chairs were purchased, one of which had its resistance system replaced by a cam-spring system with mechanical vibration and the other was kept completely original to be used in the tests as a basis for comparison, with identical postural parameters. The new equipment is simple, compact, low inertia and allows mechanical vibrations to be applied in the direction of muscle shortening with adjustable frequency and amplitude. Due to its low inertia design, the equipment also allows milimetric load variation and exercises to be performed at higher speeds and with less risk of injury. The comparative tests evaluated the activation amplitude of the electromyographic signal in the right and left rectus femoris muscles of trained individuals during bilateral extension/flexion movements on the conventional chair and the new equipment. The sample consisted of 7 trained male volunteers aged between 18 and 40. The protocol consisted of 4 types of exercise: conventional machine with controlled speed (CEC), new machine with controlled speed (CAME), new machine with controlled speed and addition of mechanical vibration (VIBRA) and new machine with maximum speed (POT). A significant increase in the amplitude of the electromyographic signal was observed in the POT compared to the other exercises, both in the concentric and eccentric phases. Overall, the equipment proved to be effective, safe and with great innovative potential for improving training gains.

2024-02-29T00:00:00Z https://repositorio.ufu.br/handle/123456789/48538 2026-03-13T06:20:42Z 2026-02-26T00:00:00Z

Title: ANDRADE, Rafael Moreira. Manufatura aditiva por deposição a arco para a recuperação de matrizes para injeção de alumínio sob pressão Abstract: Extending the service life of tooling in the high-pressure aluminum die-casting industry represents a technical and economic challenge, given the severity of the cycles to which these components are subjected. In this scenario, Wire Arc Additive Manufacturing (WAAM) emerges as a strategic alternative for the restoration of functional surfaces. The present study investigated the technical and metallurgical feasibility of applying WAAM for die repair, comparing the performance of three distinct alloys: Maraging 250 (solid wire), Martensitic Stainless Steel 420 (solid wire), and H13 Tool Steel (metal-cored wire). Initially, a decommissioned mold was characterized to identify the predominant failure mechanisms, thereby establishing the requirements to be met by additive manufacturing. The welding stability of the Maraging alloy was also investigated regarding three shielding atmospheres, while also varying two different deposition strategies. Maraging 250 steel stood out for its strength and structural integrity. The alloy benefited from the reheating thermal cycles intrinsic to the process, which promoted in-situ aging, resulting in a hardness gradient. In contrast, the martensitic alloys (Stainless Steel 420 and H13) showed high sensitivity to deposition strategies and cooling rates. It was observed that low heat input strategies resulted in the formation of untempered martensite, leading to brittle fracture. Implementing strategies aimed at heat accumulation enabled the processing of 420 Stainless Steel through the auto tempering mechanism, restoring the necessary ductility; however, this approach proved insufficient to mitigate cracking in H13 Tool Steel due to its high hardenability and segregation of brittle phases. Thus, thermal management is fundamental for the application of WAAM in tool steels, validating Maraging steel as the most robust solution for the remanufacturing of high-performance molds.

2026-02-26T00:00:00Z