It is known that hot tearing tendency increases with the increase in the cooling rate of casting during the solidification. As the direct control factors of the hot tearing, the cooling rate dependences of the tempera...
详细信息
To reduce the structural weight and volume and satisfy an optimal balance of performance constraints, a study using a porous rectangular foldable board and structurally improved trolley model was conducted, and motion...
To reduce the structural weight and volume and satisfy an optimal balance of performance constraints, a study using a porous rectangular foldable board and structurally improved trolley model was conducted, and motion simulations were performed to derive the static and transient structural properties. The simulations revealed that the fatigue lifetimes of both the main structure and the porous boards were in a high-standard-value range, whereas the transient analysis indicated that both the directional deformation and equivalent stress exhibited minimal local values. For porous boards simply supported only on two sides, the trolley had a much smaller collapsed volume than other types of trolley. The static analysis indicated that this trolley prototype had a good safety coefficient and long fatigue lifetime. The transient analysis showed that the porous area had a higher strength and bending load than the non-porous area. The overall transient response was close to that of a steady-state, showing a negligible effect on the ***.
Market competitiveness and pressure for rational use of resources led manufacturers to look for optimized electromagnetic devices. The large number of variables involving the design of this technology, as well as the ...
详细信息
Market competitiveness and pressure for rational use of resources led manufacturers to look for optimized electromagnetic devices. The large number of variables involving the design of this technology, as well as the compromise between performance and efficiency, have provide the opportunity to adopt optimization techniques in their design stage. Recently, a wide variety of both traditional and nontraditional mathematical algorithms have been introduced to solve challenging and practical optimization problems related to electromagnetic equipment. Evolutionary metaheuristics are general-purpose optimization algorithms inspired by natural self-organized systems and by biological evolution. An optimization method, called Extremal Optimization (EO), which is based on a simplified model of natural selection, was developed to show the emergence of self-organized criticality based on Bak-Sneppen model in ecosystems. Recently, a generalized version of EO method, called Generalized Extremal Optimization (GEO), was proposed. This technique can be applied to a broad class of design optimization problems. In order to enhance and to improve the search performance and efficiency of GEO, a novel Diversity-guided GEO (DGEO) metaheuristic algorithm, with focus in global continuous optimization, is proposed and investigated in this paper considering the design stage of an electromagnetic device. The analysis was carried for a single-phase transformer and revealed that DGEO provided considerable better performance in convergence speed and solution quality than standard GEO.
Based on the formulation of the problem to be discussed by the writer is to know: the influence of 0.4 mm spark gap variation, and standard spark plug type, to CO and HC, the influence of 0.5 mm spark plug gap variati...
详细信息
Phase Change Materials (PCM) present a great potential for energy efficiency gains in thermal systems, e.g. by storing solar energy in buildings or heat loads in industrial processes. This is because a great amount of...
Phase Change Materials (PCM) present a great potential for energy efficiency gains in thermal systems, e.g. by storing solar energy in buildings or heat loads in industrial processes. This is because a great amount of energy can be stored per mass unit within a small temperature range. Significant applications of this peculiar characteristic of PCM regard the effective adoption of macro-encapsulated PCM into building envelopes. Several studies on this topic tend to be limited to a sort of “material selections” on PCM and a lack of systematic analysis has consequently emerged. In order to guarantee an effective use coupled with economic feasibility, a deep understanding of the phase transition phenomenon is needed. The study of PCM using computational fluid dynamics (CFD) is documented in several works, in accordance with the current trend of CFD to become increasingly widespread. Numerical studies on solidification and melting processes use a combination of formulations to describe the physical phenomena related to such processes, mainly the latent heat and the velocity transition between the liquid and the solid phases. The methods used to describe the latent heat are divided in three main groups: (i) source term methods (E-STM), (ii) temperature transforming models (E-TTM) and (iii) enthalpy methods (E-EM). The description of the velocity transition is in turn divided in three main groups: (i) switch-off method (SOM), (ii) source term method (STM) and (iii) variable viscosity method (VVM). In this context, the main objective of the present paper is to review the numerical approaches used to describe solidification and melting processes.
A geometrical base parameter is investigated to determine the effect on a bending quality of a thin sheet metal for a roll forming process. This parameter is usually used as a criterion for the quality control of inco...
详细信息
In this paper the vibration analysis of a cantilever beam with viscoelastic neutralizer using fiber Bragg gratings (FBG) is presented. The optimal design, of the neutralizer, is achieved through a robust methodology d...
详细信息
Multi-rotor unmanned aerial vehicles (UAVs) have become common in recent years, but non-rotor UAVs are still relatively rare. This study used an aerodynamic model to replace the multi-rotor design concept and examine ...
详细信息
This papers presents a new heuristic multiobjective optimization procedure based on Kalman filtering. The novel approach is compared to the well-known Nondominated Sorting Genetic Algorithm version II with the Zitzler...
详细信息
作者：
Gasparin, SuelenBerger, JulienDutykh, DenysMendes, NathanLAMA
UMR 5127 CNRS Université Savoie Mont Blanc Campus Scientifique Le Bourget-du-Lac CedexF-73376 France Thermal Systems Laboratory
Mechanical Engineering Graduate Program Pontifical Catholic University of Paraná Rua Imaculada Conceição 1155 Curitiba - ParanáCEP: 80215-901 Brazil LOCIE
UMR 5271 CNRS Université Savoie Mont Blanc Campus Scientifique Le Bourget-du-Lac CedexF-73376 France Univ. Grenoble Alpes
Univ. Savoie Mont Blanc CNRS LAMA Chambéry73000 France
It is well known that thermal insulation is a leading strategy for reducing energy consumption associated to heating or cooling processes in buildings. Nevertheless, building insulation can generate high expenditures ...
详细信息
暂无评论