Mechanical and Aerospace Engineering, ICMAE2011

Volumes 110-116

doi: 10.4028/

Paper Title Page

Authors: Velidi Gurunadh, Ugur Guven
Abstract: Especially in the 21st century, the space has become the actual final frontier for mankind. The possibilities are endless, as there are a lot of frontiers that can be covered in space exploration. Unfortunately, two main problems prevail in space exploration. The first problem is that the distances that need to be covered are extremely large and the second problem is the need for energy for any outpost installation in space. Fortunately, the availability of nuclear technologies allow for solution of these problems. In this paper, it is demonstrated that by using nuclear technology, traveling time can be greatly reduced and the energy requirements of the astronauts onboard a spacecraft or a space station can be met.
Authors: R. Mehdipour, C. Aghanajafi, A. Ashrafizadeh, Z. Baniamerian
Abstract: Providing a suitable thermal condition for the paint to be cured is of important parameters in achieving a desired cure. Continuous radiation ovens are of widely used apparatuses in paint cure and coating industries. Designing of these ovens for curing bodies of complex geometries have become a challenge for many years. In the present study a designing method is introduced and advised because of its acceptable capabilities. This method is based on cure window criterion and applies gradient optimization technique. The time consumed for designing is tried to be decreased through this model. A significant part of the time of designing procedure usually devotes to calculation of the physical model and to the iterations of optimization procedure. In this regard, defining a proper objective function efficiently reduces the designing time. Procedure of finding an appropriate objective function has been comprehensively discussed in the present article. Capability of the proposed methods is then evaluated for a simple two dimensional geometry of an automobile.
Authors: Hyeonmin Jo, Chaesil Kim, Sooyong Cho
Abstract: Studies on bearing properties have been carried out to develop a rotor system with improved high-speed stability and high efficiency. However, there have been few presentations on systematic design of a tilting pad journal bearing with analysis of rotor vibration and fluid properties. Therefore, this paper presents a method to systematically design a tilting pad journal bearing, where stability of the rotor system is taken into consideration, using the general-purpose software, ARMD. This paper describes the bearing design process, which meets the conditions of 0.12mm-bearing clearance and metal temperature below 75°C.
Authors: Xiang Meng Zhang, Ben Li Wang, Xian Ren Kong, A Yang Xiao
Abstract: In this paper, He’s homotopy perturbation method (HPM) is applied to solve harmonically forced Duffing systems. Non-resonance of an undamped Duffing system and the primary resonance of a damped Duffing system are studied. In the former case, the first-order analytical approximations to the system’s natural frequency and periodic solution are derived by HPM, which agree well with the numerical solutions. In the latter case, based on HPM, the first-order approximate solution and the frequency-amplitude curves of the system are acquired. The results reveal that HPM is an effective technique to the forced Duffing systems.
Authors: Wei Xiong, He Hua Ju, Hong Yun Liu
Abstract: Transparency and stability are two key issues in bilateral teleoperation. In this paper, We propose a novel control framework for bilateral teleoperation of nonlinear robotic teleoperation systems under constant communication delays. The proposed approach utilizes the modified wave variable method based on the adaptive nonlinear control, the master and slave robots are directly connected over the delayed communication channels. To make the stability of the system independent of the communication delay, two nonlinear adaptive motion/force controllers are bilaterally designed for both master and slave manipulators and insured its passivity. To improve the transparency, a modified wave variable method based on Nimeyer-Slotine wave ways was used. Simulation results are presented which demonstrate the effectiveness of the proposed architecture.
Authors: Morteza Mirzaei Amirabad, Alireza Mirzaei Amirabad, Jafar Khodagholizadeh, Ali Akbar Naeimi
Abstract: In this paper, we discus about production Hydrogen for industrial and laboratories. We will discuss about methods of production Hydrogen and exquisite in electrolysis Power Acids. In this paper, compare some methods and materials. We prefer Sulfuric Acid. For electrolysis Sulfuric Acid, we need electrode. The material of electrode must refractory in corrosion by Sulfuric Acid. This material is alloy from palatine and other material. The physical face of electrode is too important and discus in this paper.
Authors: P. Buaphad, P. Thamboon, C. Tengsirivattana, J. Saisut, K. Kusoljariyakul, M.W. Rhodes, C. Thongbai
Abstract: This work reports an application of reflective terahertz (THz) imaging for identification of water distribution in the proton exchange membrane (PEM) fuel cell. The THz radiation generated from relativistic femtosecond electron bunches is employed as a high intensity source. The PEM fuel cell is designed specifically for the measurement allowing THz radiation to access the flow field region. The THz image is constructed from reflected radiation revealing absorptive area of water presence. The technique is proved to be a promising tool for studying water management in the PEM fuel cell. Detailed experimental setup and results will be described.
Authors: Liu Xue Zhang, Xiu Lian Wang
Abstract: Fine particles of photoactive anatase-type TiO2, prepared by hydrolysis of tetrabutyl orthotitanate and crystallized under microwave (MV) irradiation, were loaded on adsorbent support attapulgite (ATP). The prepared hybrids TiO2-ATP were characterized with transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and X-ray diffraction (XRD) and photoactivity properties were evaluated separately. The substrates of target were adsorbed on the adsorbent support, and then a high concentration environments of the substrate was formed around the loaded TiO2, resulting in an increase in the photodestruction rate. One of the most interesting features of the resulting catalysts with low titania contain (<30%) is their fast decantability in comparison with that of TiO2. This way one of the most important drawbacks of photocatalysis, the catalysts separation from the solution, was overcome by simple sedimentation and decantation. The low concentrations MB may be removed through enrichment and photodegradation using the prepared TiO2-ATP photocatalyst.
Authors: Yu Wang, Zhen Luo
Abstract: This paper presents a level set-based structural shape and topology optimization for the design of compliant mechanisms. The design boundary of the compliant mechanism is implicitly represented as the zero level-set of a higher-dimensional level set surface. A quadratic energy functional is introduced to augment the objective function in order to control the structural geometric size of the resulting mechanism. The optimization is thus changed to a numerical process that describes the design as a sequence of motions by updating the implicit boundaries until the optimized structure is achieved under specified constraints. A semi-implicit scheme with an additive operator splitting (AOS) algorithm is used to solve the Hamilton-Jacobi partial differential equation (PDE) in the level set method. In doing so, it is expected that numerical difficulties in most conventional level set methods can be eliminated. The final mechanism is characterized with strip-like members able to generate distributed compliance, and so that to resolve the hinge problem long sought-after in the design of compliant mechanisms. Typical numerical case is used to evidence the effectiveness of this method in the design of monolithic compliant mechanisms.
Authors: Nemat Changizi, Mahbubeh Moghadas, Mohamad Reza Dastranj, Mohsen Farshad
Abstract: In this paper, an intelligent speed controller for DC motor is designed by combination of the fuzzy logic and genetic algorithms. First, the speed controller is designed according to fuzzy rules such that the DC drive is fundamentally robust. Then, to improve the DC drive performance, parameters of the fuzzy speed controller are optimized by using the genetic algorithm. Simulation works in MATLAB environment demonstrate that the genetic optimized fuzzy speed controller became very strong, gives very good results and possesses good robustness.

Showing 341 to 350 of 820 Paper Titles