Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Nesrin Demir is active.

Publication


Featured researches published by Nesrin Demir.


Journal of Applied Mechanical Engineering | 2013

Numerical study on the performance of anode supported tubular SOFC

Gamze Gen M Fatih Kaya Hseyin Yapici; Nesrin Demir

T paper topic relates to modeling for control applications and control of constrained mechanical systems. It presents a unified control architecture designed for motion planning, tracking, following or both tracking and following, for constrained systems, specifically nonholonomic. It provides a systematic and unified approach for planning desired motions, e.g. tasks referred to as programs required to be performed by systems, and their tracking provided they may be specified by equations of constraints and error functions, either algebraic or differential. The strategy developed based on this control architecture is referred to as a model reference tracking control strategy for programmed motion. It is based on reference dynamics and one dynamic control model for constrained systems, which is not sensitive to the task-based constraint kind and order. The reference dynamics is derived by the generalized programmed motion equations (GPME) method, which enables merging all tasks requested for the controlled system into one constrained dynamics. The preplanned motion, which is a reference motion in control, may be executed by control algorithms dedicated to nonlinear systems and even these dedicated to holonomic systems. The theoretical framework is illustrated by the examples of motion tracking and both tracking and following for constraint systems, where the constraints are task-based and for which the classical control oriented dynamics modeling and control methods may not work. Elzbieta Jarzebowska, J Appl Mech Eng 2013, 2:3 http://dx.doi.org/10.4172/2168-9873.S1.002V few studies were conducted on space missions considering oral health conditions. So, this study was planned to explore effect of long duration Space Exploration Analog and Simulation on oral health and possible cause of compromised oral health. It is mainly required to consider the oral health during long duration mission by means of noninvasive studies on oral cavity immunity and oral microbial. Microbiological analyses of the oral flora and salivary biomarkers have been suggested as a suitable method for evaluating oral health. Further study is needed to prove this fact in real space mission. Balwant Rai, J Appl Mech Eng 2013, 2:3 http://dx.doi.org/10.4172/2168-9873.S1.002F control is one of the major topics in fluid mechanics aimed at altering unnatural flow state into a more desired state. Since most engineering flows include complex conditions, emphasis has been put on development of active controls in recent decades, Gad-el-Hak (2007). One of the well-known active control techniques is blowing/suction perturbations, which is used experimentally or numerically by many investigators. A detailed numerical analysis of the influence of steady and unsteady blowing/suction over span wise slots on the velocity and thermal fields in a turbulent channel is introduced by Araya et al. (2008, 2011). They concluded that intensification in the wall shear stress fluctuations was the major cause of skin friction, wall heat flux, and Stanton number augmentation downstream from the local forcing source. In this study, we are using extensive and highly accurate DNS to elucidate the effects of blowing and suction over spanwise holes on the drag reduction and heat transfer coefficient at Re = 394 based on the friction velocity. In addition, the corresponding influence of perturbing amplitudes and angles on the energy budget of velocity fluctuations, thermal fluctuations and mean vorticity are discussed extensively. Furthermore, proper orthogonal decomposition (POD) of the channel flow is analyzed in this study and the energy redistribution of POD modes by the effects of blowing/suction perturbations are shown. Can Liu, J Appl Mech Eng 2013, 2:3 http://dx.doi.org/10.4172/2168-9873.S1.002M industry trends, including rising fuel cost, increasing safety requirements, passenger comfort, and environmental responsibility are driving the aircraft industry to develop technology with light weight materials, replace mechanical systems with electronic systems, utilize more sophisticated and efficient control systems and embedded software, and improve aerodynamic efficiency. With emergent competition from China, Russia and elsewhere there is continued pressure to innovate while compressing development schedules. Simulation is a powerful enabling technology at all stages in the design process from functional and architectural design through detailed design and verification and validation. Along the design journey the simulation tools used vary in complexity, order and by engineering discipline. To address the industry trends and the implications for engineering design, aerospace organizations are integrating their often segregated simulation best practices throughout the design process and across functional disciplines. In this paper a model based systems and embedded software engineering workflow is introduced that in a common simulation environment spans requirements management, functional and architectural definition through to detailed 3D design and optimization using physics based simulation. A demonstration will be presented for an aircraft flight control system. Vincent Delafosse, J Appl Mech Eng 2013, 2:3 http://dx.doi.org/10.4172/2168-9873.S1.002I The development of fiber-reinforced composites has constituted a revolution of material technology in aerospace structural applications. To take advantages of the unique properties of fiber reinforced composites, a composite structure often contains multiple layers laminated together with each layer oriented in the direction of the structural function. Analysis of these structures in laminate level has widely employed “Classical Laminated Plate Theory” in determining the ply stresses. However, in analysis of structural level, finite element method is often adopted. FEM is a viable technique to solve the structural problems but its model is the problem dependent. The common non-FEM approach used in analyzing composite beam structures is to calculate the equivalent stiffness of each sub-laminate by lamination theory and then used it to calculate the section property of the structure as the method used in the isotropic structures. In so doing, the coupling effects of the structural level were ignored. The main objective of this paper is to present newly developed methods for bridging the analysis between laminate and structural levels for composite beam structures such as I-beam, Cbeam, and tubular structures under loads. The closed form expressions of the sectional properties such as bending/torsional stiffness, centroid and shear center of the cross-sections as a function of material properties, fiber orientation and stacking sequence are presented. In the present method, the structural responses such as coupling effects due to unsymmetrical and/or unbalanced of laminate as well as unsymmetrical cross-section are included. The present results were validated well by FEM model. Wen S. Chan, J Appl Mech Eng 2013, 2:3 http://dx.doi.org/10.4172/2168-9873.S1.002T products in the A&A industry have become more complex than ever before as have the related processes, such the A380 or Boeing 787 airplanes. The product lifecycle management concept has been broadly addressed as a holistic approach to connect product and process modeling domains so that the industry can take full advantage of engineering informatics supported by modern information and computer technologies (ICTs). However, the A&A industry and the related academic research are not interfaced well enough to support healthy development cycles. It can be appreciated that the industry demands coherent answers to address those “big-picture” thematic problems instead of just the “micro” solutions currently on offer. Formulating systematic research programs with highly specified interfaces among research “nuggets” is the promising approach of governments, corporations, and clusters of smalland medium-sized players. Researchers, on the other hand, should identify their works with the “local coordinates” of a bigger picture driven by the industry and should constantly adapt their individual solutions such that they are always ready to be integrated seamlessly with other collaborative solutions. The interfacing edge definition of the puzzle, i.e. semantics standardization, is the imperative research task for both the industry and the related academic research circle. The proposed session is to develop some common understanding and explore the new challenges for the next step research in both the industrial applications and academic research fields. Yongsheng Ma, J Appl Mech Eng 2013, 2:3 http://dx.doi.org/10.4172/2168-9873.S1.002L Re number flows are seen on mini, micro and unmanned air vehicles, wind turbine blades, model aircrafts, birds and little creatures like bees or flies. Due to the advances in unmanned aerial vehicles, micro air vehicles and wind turbines, aerodynamics researches concentrated on low Reynolds number aerodynamics, transition and laminar separation bubble and its effects on aerodynamic performance. Today, high performance computing capabilities make it possible to routinely use RANS based CFD methods for simulating high and low Reynolds number flows. Recently, transport equation models which rely on local information to circumvent some complicated procedures in the early methods, have been introduced. These transport equation models solve several transport partial differential equations written for various transition quantities in addition to the baseline turbulence models. Some of these models have been made available in a number of commercial CFD codes, and assessment of transport equation models has been made by different authors including trials of different user-dependent transition correlations. Transition-sensitive, single point eddy viscosity models are fairly new, and performance assessments of these models are required. The first aim of this study is to evaluate the performance of transition and turbulence models for predicting of low Re number flows which have a laminar separation bubble, which is traditionally very difficult for RANS-based CFD. Mustafa Serdar Genc, J Appl Mech Eng 2013, 2:3 http://dx.doi.org/10.4172/2168-9873.S1.002


Journal of Applied Mechanical Engineering | 2013

Numerically Modeling of Anode Supported Tubular SOFC

M Fatih Kaya; Nesrin Demir; Gamze Genç; Hüseyin Yapıcı

Numerical models of Solid Oxide Fuel Cells (SOFCs) are important tools in understanding and investigate the effect of design and operation parameters of the SOFC performance and SOFC development works. In this study, one of the clean and highly efficient energy production systems, single tubular anode-supported SOFC is modeled numerically. Mathematical model of the single tubular SOFC is given in terms of the incompressible Navier- Stokes, Knudsen diffusion models, Butler–Volmer kinetic equations and Brinkman equations. For two-dimensional axisymmetric geometry, operating conditions, parameters of fuel cell and governing equations are solved by finite element method software ComsolMultiphysics. Pure H2 89% and H2O 11% are used at anode and air is used at the cathode side as reactant gasses. Temperature, pressure, porosity, permeability and especially distance of current collectors to the cell reactant gas inlet are studied. Optimal cell parameters for this model are determined and reasons of cell performance effects are explained.


Annals of Nuclear Energy | 2008

A comprehensive study on neutronics of a lead–bismuth eutectic cooled accelerator-driven sub-critical system for long-lived fission product transmutation

Hüseyin Yapıcı; Gamze Genç; Nesrin Demir


Annals of Nuclear Energy | 2007

Neutronic limits in infinite target mediums driven by high energetic protons

Hüseyin Yapıcı; Gamze Genç; Nesrin Demir


Journal of Fusion Energy | 2006

Neutronic Analysis for Transmutation of Minor Actinides and Long-Lived Fission Products in a Fusion-Driven Transmuter (FDT)

Hüseyin Yapıcı; Nesrin Demir; Gamze Genç


International Journal of Hydrogen Energy | 2010

Hydrogen production via water splitting process in a molten-salt fusion breeder

Gülşah Özişik; Nesrin Demir; Mustafa Übeyli; Hüseyin Yapıcı


Journal of Fusion Energy | 2008

Time-dependent Neutronic Analysis for High Level Waste Transmutation in a Fusion-driven Transmuter

Hiiseyin Yapici; Nesrin Demir; Gamze Genç


Fusion Engineering and Design | 2006

Transmutation–incineration potential of transuraniums discharged from PWR-UO2 spent fuel in modified PROMETHEUS fusion reactor

Hüseyin Yapıcı; Gamze Genç; Nesrin Demir


International Journal of Hydrogen Energy | 2013

Hydrogen production via steam-methane reforming in a SOMBRERO fusion breeder with ceramic fuel particles

Nesrin Demir


Energy Conversion and Management | 2006

Study on spent fuel rejuvenation in PROMETHEUS fusion reactor

Hüseyin Yapıcı; Nesrin Demir; Gamze Genç; Bilge Çeper

Collaboration


Dive into the Nesrin Demir's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Mustafa Übeyli

TOBB University of Economics and Technology

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge