The present paper shows a geometric evaluation of stiffened plates subjected to a uniformly distributed transverse loading. For that, it was proposed a set of different geometric configurations through the Constructal Design method, which were numerically simulated. Then, by means of the Exhaustive Search technique, a geometric optimization was performed aiming to minimize the central deflection of the plate. A non-stiffened plate measuring 2.00 m x 1.00 m x 0.02 m was used as reference, then a constant volume ratio ?, equals to 0.5, was taken from the reference plate and transformed into longitudinal and transverse stiffeners. The geometric parameters considered as degrees of freedom were: the number of longitudinal (Nls) and transverse (Nts) stiffeners and hs/ts, which is defined by the ratio between the stiffener’s height and thickness. In order to elaborate the computational model, it is used ANSYS Mechanical APDL®, a software based on the Finite Element Method (FEM). From the results, it was possible to determine a power function for each combination of Nls and Nts that accurately described the relation between the central deflection and hs/ts. Furthermore, it was noticed a substantial influence of the geometric parameters under analyses regarding the studied structural element’s mechanical behavior. Even though the volume was kept constant, the optimized geometry has shown a result 9110 % better compared to the one shown by the reference plate.

Furfural residue is a detrimental waste generated in furfural production processes. Combustion is an efficient way to dispose furfural residue and drying is a necessary unit operation prior to combustion. In this paper, the properties of furfural residue, including particle size distribution, proximate analysis and pyrolysis process curves were presented. The flow and drying characteristics of furfural residue in a lab-scale single-shaft paddle heat exchanger were documented. The measurements show that the furfural residue contains high moisture (54.26%) and its as received basis lower heating value is 7301 kJ/kg. The high moisture content in furfural residue makes ignition and efficient combustion very difficult. It is feasible to use single-shaft paddle heat exchanger to dry furfural residue to moisture content of 15.94% which is advantageous for further combustion due to low moisture content. No agglutination and blockage were found. This preliminary experimental research provides reference for furfural residue drying unit design.

In this study, we show the effect of time delay of coolant fluid flow into a vascularized plate on the peak temperature. Coolant flows along vascular channels which were embedded in a rectangular plate. Two kinds of vascular channel designs were investigated experimentally: parallel and tree-shaped. In the study, the peak temperatures were monitored and the coolant was pumped when the peak temperature reaches to 50°C, 70°C and 90°C. The performance comparison of two distinct designs is based on two criteria: the time required for the steady state condition after the coolant is pumped and the peak temperature after the steady state condition is conformed. The results show that the time required to reach steady-state condition increases as the time delay increases. The parallel and tree-shaped designs show similar performance (time required to reach steady state) with slightly improved performance in the tree-shaped design as the preset temperature for time delay increases. For instance, 4% decrease in the time required to reach steady-state with the tree-shaped design relative to the parallel design was achieved when the preset temperature for time delay is 90°C.

There are several areas of engineering that use thin plates as structural elements, among them, we can highlight their application in the construction of offshore structures, bridges, ship hulls, and aircraft fuselage. In some design situations, the plates may be subjected to compression stresses and, consequently, they may be under the effect of elastic and/or elasto-plastic buckling. The analysis of the buckling phenomenon presents significant differences between one-dimensional elements, such as beams and columns, and two-dimensional elements, such as plates. The buckling phenomenon is directly related to dimensional, constructive and/or operational aspects. In this sense, the presence of perforations in plates causes a redistribution of their stresses, affecting not only their resistance but also their buckling characteristics. In order to solve the problem of elasto-plastic buckling in thin steel plates with perforations, we used computational models developed in Ansys(R) software, which is based on the Finite Element Method (FEM). For the analysis, it was considered perforated plates with constant thickness h for the relationships H/L = 1.0 and H/L = 0.5, where H is the plate width and L is the plate length. For the volume fraction ?, i.e., the ratio between the volume of the perforation and the volume of the plate, the following values were considered: 0.08; 0.10; 0.15; 0.20 and 0.25. In addition, the plates were considered to have centralized perforations with the following geometric forms: longitudinal oblong, transverse oblong, elliptic, rectangular, diamond, longitudinal hexagonal, and transverse hexagonal. The shape variation of each perforation type occurs through the ratio H0/L0, being H0 and L0 the characteristics dimensions of perforation. The Constructal Design method was employed to define the range of possible geometries for the perforated plates, allowing an adequately comparison about the von Mises stress distribution among the studied cases. The results show that the geometric shape variation, for all analyzed perforation types, leads to an optimum geometry.

The rapid growth of wind power generation and the need for a smarter grid with decentralized energy generation has increased the interest in vertical axis wind turbines (VAWT), especially for the urban areas. For the urban areas the VAWT offer several advantages over the horizontal ones, so their acceptance is rising. The lift-type VAWT (Darrieus wind turbines) have a natural inability to self-start without the help of extra components. The existing methodologies are usually used to optimize the wind turbine performance, but not its ability to self-start. Indeed, studying the aerodynamic behavior of blade profiles is a very complex and time-consuming task, since blades move around the rotor axis in a three-dimensional aerodynamic environment. Hence, a new methodology is presented in this paper to study the self-start ability of VAWT, which offers a substantial time reduction in the first steps of new blade profiles development. Both symmetrical and asymmetrical airfoils are targeted in our study, presenting comprehensive results to validate our methodology.

This paper focused on developing a methodology based on coupling the Genetic Algorithm (GA) and the Boundary Element Method (BEM) for predicting the mechanical properties of a soil if a previous displacement x frequency curve is known. The NSGA-II (Elitist Non-Dominated Sorting Genetic Algorithm) was chosen for optimizing a dynamic poroelastic problem. The revisited problem introduced by Cheng is the benchmark used to verify the numerical routine and to apply the proposed optimization procedure. The present methodology was shown to be able to predict the mechanical properties of the underground soil if a displacement x frequency curve is previously known.