Afyonkarahisar, Turkey
Afyonkarahisar, Turkey

Afyon Kocatepe University is a state university in Afyonkarahisar, Turkey. It was established on July 3, 1992. Wikipedia.

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Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: AAT.2011.4.4-3. | Award Amount: 50.74M | Year: 2011

The project proposal concerns the challenges posed by the physical integration of smart intelligent structural concepts. It addresses aircraft weight and operational cost reductions as well as an improvement in the flight profile specific aerodynamic performance. This concerns material concepts enabling a conformal, controlled distortion of aerodynamically important surfaces, material concepts enabling an active or passive status assessment of specific airframe areas with respect to shape and potential damages and material concepts enabling further functionalities which to date have been unrealizable. Past research has shown the economic feasibility and system maturity of aerodynamic morphing. However, few projects concerned themselves with the challenges arising from the structural integration on commercial aircraft. In particular the skin material and its bonding to the substructure is challenging. It is the aim of this project proposal to demonstrate the structural realizability of individual morphing concepts concerning the leading edge, the trailing edge and the winglet on a full-size external wing by aerodynamic and structural testing. Operational requirements on morphing surfaces necessitate the implementation of an independent, integrated shape sensing system to ensure not only an optimal control of the aerodynamic surface but also failure tolerance and robustness. Developments made for structural health monitoring will be adapted to this task. Similar systems optimized for rapid in-service damage assessment have progressed to a maturity which allows their inclusion in the next generation of aircraft. However, the time consuming application of these sensor systems has to be further improved by integration at the component manufacturing level. The additional benefit of a utilization of these adapted systems for part manufacture process and quality control shall be assessed in SARISTU. Addressing the Nanotechnology aspect of the call, benefits regarding significant damage tolerance and electrical conductivity improvements shall be realized at sub-assembly level.

Aksoy L.,Afyon Kocatepe University
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2011

Nigella sativa is a plant known for its uses as herbal and medical purposes. Seeds of Nigella sativa have a high level of oil content. In this study, biodiesel is produced from Nigella sativa oil by using the transesterification method. An acid catalyst is used since Nigella sativa oil has 5.36% free fatty acid content. Parameters such as catalyst ratio, methanol ratio and temperature are optimized for 3 hours of reaction period. Optimal conversion efficiency is obtained to be 82.74% at 40 wt.% methanol/oil ratio, 4 wt.% catalyst concentration, and 70°C reaction temperature. Methyl esters in Nigella sativa biodiesel are determined by Gas Chromatography-Frame Ionized Detector (GC-FID). Some basic characteristics of the produced methyl ester are determined and it is concluded that it possesses some requirements for biodiesel standards. © Sila Science.

Bayrakceken H.,Afyon Kocatepe University
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2011

In this study, biodiesel was produced from waste animal tallow using transesterification method. Viscosity of animal tallow methyl ester is approximately 1.77 times greater than that of diesel fuel. Preheating was applied in this study to decrease the viscosity of animal tallow methyl ester. Preheating temperatures were determined to be 70 °C and 100 °C. The effects of the fuel without preheating at 30°C (B100-30), and the fuels with preheating at 70 °C (B100-70), and 100°C (B100-100) on engine performance and emissions were analyzed. Significant changes were observed in engine power and specific fuel consumption with the application of preheating to biodiesel. Specific fuel consumptions of B100-30, B100-70, and B100-100 fuels increased on average by 16.41%, 12.48%, and 6.59%, respectively. CO emissions of B100-30, B100-70, and B100-100 fuels decreased on average by 23.98%, 38.92%, and 45.77%, respectively. When compared to diesel fuel, NO x emissions of B100-30 and B100-70 fuels increased on average by 10.61% and 8.36% respectively, while NO x emissions of B100-100 fuel decreased by 3.85%. © Sila Science.

Hocaoglu F.O.,Afyon Kocatepe University
Solar Energy | Year: 2011

Mathematical modeling of solar radiation continues to be an important issue in renewable energy applications. In general, existing models are mostly empirical and data dependent. In this paper, a novel approach for solar radiation modeling is proposed and illustrated. The proposed application consists of hidden Markov processes, which are widely used in various signal processing topics including speech modeling with successful results. In the experimental work, mean of hourly measured ambient temperature values are considered as observations of the model, whereas mean of hourly solar radiation values are considered as the hidden events, which constitute the outcomes of the proposed mathematical model. Both solar radiations and temperatures are converted to quantized number of states. Finally, after a training stage that forms the transition probability values of the described states, the hidden Markov model parameters are obtained and tested. The tests are repeated for various numbers of states and observations are presented. Plausible modeling results with distinct properties in terms of accuracy are achieved. © 2010 Elsevier Ltd.

In this study energy, exergy and exergoeconomic analysis of the Afyon geothermal district heating system (AGDHS) in Afyon, Turkey is performed through thermodynamic performances and thermo-economic assessments. In the analysis, actual system data are used to assess the district heating system performance, energy and exergy efficiencies, exergy losses and loss cost rates. Energy and exergy losses throughout the AGDHS are quantified and illustrated in the flow diagram. The energy and exergy efficiencies of the overall system are found to be 37.59% and 47.54%, respectively. The largest exergy loss occurs in the heat exchangers with 14.59% and then in the reinjection wells with 14.09%. Besides, thermo-economic evaluations of the AGDHS are given in table. Energy and exergy loss rates for the AGDHS are estimated to be 5.36. kW/$ and 0.2. kW/$, respectively. © 2010 Elsevier Ltd.

Aksoy F.,Afyon Kocatepe University
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2011

Today, various methods are used in order to decrease the emissions arising out of diesel engines. One of these methods is addition of additives, which contain oxygen, into the diesel fuel. In this study, effect of addition of 5% and 10% MTBE (methyl tertiary butyl ether) in volume into the diesel engine on engine performance and emissions has been tested in a diesel engine with single cylinder and direct injection. When compared to the diesel fuel, engine power has decreased by 3.11% and 5.4% through use of MTBE 5 and MTBE 10 fuels, respectively; specific fuel consumption has increased. It is observed that there are developments with regard to CO and NO x emissions when compared to the diesel fuel. © Sila Science.

Diatomite is a pozzolanic material containing amorphous silica, cristabolite and minor amounts of residual minerals. Waste marble powder (WMP) is an inert material which is obtained as an industrial by product during sawing, shaping, and polishing of marble and causes a serious environmental problem. This paper describes the procedures and results of a laboratory investigation of mechanical properties carried out on the concrete specimens containing diatomite and WMP as partial replacement of cement in concrete. The laboratory work essentially consists of characterization of the raw and waste materials, preparation of concrete specimens with diatomite and WPM in different ratios by weight as replacement for cement and a superplasticizing admixture to reduce water demand and compression and flexural tests of the specimens. Test results indicated that the concrete specimens containing 10% diatomite, 5% WPM and 5% WPM +10% diatomite replacement by weight for cement had the best compressive and flexural strength and the replacement of cement with diatomite and WMP separately and together using a superplasticizing admixture could be utilized to improve the mechanical properties of the conventional concrete mixtures. © 2010 Elsevier Ltd. All rights reserved.

Karaarslan A.,Afyon Kocatepe University
IEEE Transactions on Industrial Electronics | Year: 2013

In this paper, a bee colony optimization (BCO) algorithm is adapted to the current control strategy of power factor (PF) correction for a Sheppard-Taylor converter. The control approach is developed to eliminate the input current harmonics in the converter. The BCO algorithm is a new population-based search algorithm which is one of the metaheuristic techniques based on swarm intelligence. This algorithm depends on modeling the natural behavior of real honey bees. In this approach, duty cycles are generated by the BCO algorithm for the Sheppard-Taylor converter switch to obtain unity PF (UPF) and lower total harmonic distortion of the input current. The duty cycles for half a line period are calculated and stored in a lookup table. By synchronizing the memory with the line, near-unity PFs can be achieved in an operating point. The feedforward is also used into the control algorithm with the maximum value of the input voltage. The implementation of feedforward improves the converter performance. The input current of the converter is operated in continuous conduction mode. The simulation and experimental results show that the proposed control strategy works well and the UPF can be achieved with wide input voltage, load, and parameter variation. The results are compatible with the International Electrotechnical Commission (IEC) 61000-3-2 current harmonic standard. © 1982-2012 IEEE.

Kecebas A.,Afyon Kocatepe University
Energy Conversion and Management | Year: 2013

This study deals with an energetic and exergetic analysis as well as economic and environmental evaluations of Afyon geothermal district heating system (AGDHS) in Afyon, Turkey. In the analysis, actual system data are used to assess the district heating system performance, energy and exergy efficiencies, specific exergy index, exergetic improvement potential and exergy losses. And, for economic and environmental evaluations, actual data are obtained from the Technical Departments. The energy and exergy flow diagrams are clearly drawn to illustrate how much destructions/losses take place in addition to the inputs and outputs. For system performance analysis and improvement, both energy and exergy efficiencies of the overall AGDHS are determined to be 34.86% and 48.78%, respectively. The efficiency improvements in heat and power systems can help achieving energy security in an environmentally acceptable way by reducing the emissions that might otherwise occur. Present application has shown that in Turkey, geothermal energy is much cheaper than the other energy sources, like fossil fuels, and makes a significant contribution towards reducing the emissions of air pollution. © 2012 Elsevier Ltd. All rights reserved.

Kecebas A.,Afyon Kocatepe University
Energy Conversion and Management | Year: 2012

Energy consumptions in buildings can be reduced considerably using insulation materials. Even in well-insulated buildings energy consumption can be reduced further by insulating transmission pipes. For this reason, the energy savings can be obtained by using proper thickness of insulation in these areas. In this study, insulation thickness has been optimized by using exergy method and life-cycle cost concept for the case of using various fuels such as coal, natural gas and fuel-oil. This analysis is based on the exergetic cost of insulation materials and fuel. As a result, combustion parameters such as excess air, stack gas temperature, and combustion chamber parameters are much more effective on optimum insulation thickness. The optimum insulation thickness decreases with the increasing of inlet temperature of fuel, and with the decreasing of excess air coefficient, temperatures of stack gases and combustion chamber. Under this effects, the optimum insulation thicknesses determine as 0.065, 0.071, 0.099 m with a rate of 68.27%, 71.54% and 77.85% in the exergetic saving for natural gas, coal and fuel-oil fuels, respectively. The optimum insulation thickness, total annual exergetic cost, exergy saving, and exergy losses depending on heat transfer increase with the increase of heating degree-days, while they decrease by increasing the temperature of outside air (reference state). In addition, the optimum insulation thickness for the exergoeconomic optimization is higher than that of energoeconomic optimization. © 2012 Elsevier Ltd. All rights reserved.

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