Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Abuşoǧlu, A.(2)
- Karaali, R.(2)
- Tozlu, A.(2)
- Çolak, M.(2)
- Özahi, E.(2)
- Adiyaman, G.(1)
- Birinci, A.(1)
- Dündar, M.(1)
- Fiçici, F.(1)
- Taş, M.(1)
- Teke, Ç.(1)
- Yilmaz, F.(1)
- Yurdakul, M.(1)
- Öner, E.(1)
- Özen, F.(1)
- İpek, M.(1)
Yayınlar
- MakaleAçık Erişim2019Scopus SJRQ3Modeling of the impact of initial mold temperature, Al5Ti1B and Al10Sr additions on the critical fraction of solid in die casting of aluminum alloys using fuzzy expert system
Teke, Ç.; Çolak, M.; Taş, M.; İpek, M.
In the casting of liquid metal, the feeding stops when the mushy zone is clogged and does not allow the transfer of feeding liquid. The growing resistance of the solid dendrites against the fluidity of the feeding liquid is defined as the critical fraction of solid (CFS). CFS value varies depending on many factors such as alloy solidification range, initial mold temperature, and the grain size. Therefore, in many casting simulation applications, it is quite common to get inconsistent results due to insufficient information about the CFS. In this study, a fuzzy expert system (FES) model has been developed in order to determine the value of the CFS in the die casting process, based on the parameters of the alloy type, the initial mold temperature, Al5Ti1B addition and Al10Sr addition. In order to create the rule base for the FES model, 54 die casting experiments have been carried out. The CFS values obtained using the FES model has revealed that the developed model of the FES predicts the CFS value in a high performance.
AtıfScopus4WoS3OpenAlex6
İncele - BildiriAçık Erişim2017Scopus SJRQ3Evaluation of marble dust for soil stabilization
Yilmaz, F.; Yurdakul, M.
Usage of marble dust was investigated for soil stabilization in the scope of utilization of waste material. Geotechnical properties, such as compaction, Atterberg limits, unconfined compressive strength of the mixtures and changes of these properties with the marble dust ratio were determined. From the test results it is seen that marble dust increases the mechanical properties of soil and application of dust wastes for soil stabilization will be an efficient practice in terms of solid waste management.
AtıfScopus20WoS11OpenAlex23İncele - BildiriAçık Erişim2017Scopus SJRQ3Effect of copper addition to aluminium alloys on surface roughness in terms of turning operation
Özen, F.; Fiçici, F.; Dündar, M.; Çolak, M.
Aluminium alloys have found usage in numerous industries due to some superior properties, such as high strength-to-weight ratios and high oxidation resistance. Aluminum alloys can be strengthened by some techniques. One of them, the most practical one, is precipitation hardening in aluminum alloys. By adding Cu, aluminum gains strength and hardness. In this work the machinability of unalloyed aluminum and aluminum alloyed with 4% and 8% of Cu have been investigated. Machinability assessment was executed in terms of surface roughness during turning operation. Specimens were manufactured by sand casting method, which is a commonly utilized casting operation. In machinability experiments, three different cutting tool materials were employed. Three different cutting speeds and three different feed rates have been used. Effect of these feeds, speeds and cutting tool materials on surface roughness has been studied. In addition, effect of Cu addition to aluminum alloys on surface roughness has been examined.
AtıfScopus9WoS6OpenAlex10İncele - BildiriAçık Erişim2017Scopus SJRQ3Thermodynamic performance assessment of different fluids in a typical organic Rankine cycle for usage in municipal solid waste power plant
Özahi, E.; Tozlu, A.; Abuşoǧlu, A.
This paper presents the energy and exergy analyses of some different organic fluids which can be used in an organic Rankine cycle adapted to a municipal solid waste power plant in the frame of energy recovery. The novelty of the study is to adapt a well-known organic Rankine cycle system theoretically to the existing municipal solid waste power plant where the exhaust gas with a temperature of almost 560 °C is sent to atmosphere causing both energy loss and air pollution, and also violating the related legislation. The efficient organic fluid that can be used in such a plant is estimated by means of the thermodynamic analyses. It is known that, in a typical municipal solid waste power plant, a considerable amount of energy is sent up from a plant chimney to the atmosphere. This waste energy can be utilized by using an adapted organic Rankine cycle system with a proper organic fluid. In this frame, some different organic fluids were examined and compared thermodynamically in this study. The optimal operation conditions of some organic fluids, R141b, isobutane, R245fa, n-pentane and n-hexane have been evaluated by means of ASPEN and EES software programs. The effects of the outlet temperature of heat source on the energetic and exergetic efficiencies and the net power output at a given pinch point temperature difference were investigated. It can be deduced from the analyses that n-hexane has the highest energetic and exergetic efficiencies at all outlet temperatures of the heat source such as 8.92% and 34.47% at 82.08°C, respectively. It can also be stated that the maximum net power output is obtained by using the organic fluid n-hexane.
AtıfScopus14WoS12OpenAlex13İncele - BildiriAçık Erişim2017Scopus SJRQ3Thermoeconomic analysis and assessment of Gaziantep municipal solid waste power plant
Tozlu, A.; Abuşoǧlu, A.; Özahi, E.
This paper presents a thermoeconomic analysis and assessment of a municipal solid waste power plant system in Gaziantep. The operation of an existing municipal solid waste power plant is described in detail and a thermoeconomical methodology based on exergoeconomic relations and specific exergy costing (SPECO) method is provided to allocate cost flows through subcomponents of the plant. SPECO method is based on a step by step procedure which begins from identification of energy and exergy values of all states defined in the present system through fuel (F) and product (P) approach and ends at the point of establishing related exergy based cost balance equations together with auxiliary equations. The actual exergy efficiency of the solid waste power plant is determined to be 47.84% which shows that 52.16% of the total exergy input to the plant is destroyed. The net electrical power output of the Gaziantep municipal solid waste power plant is 5.655 MW. The total cost rate of the power plant is evaluated as 18.44$/h as a result of thermoeconomic analyses.
AtıfScopus12WoS13OpenAlex16İncele - MakaleYalnız künye2017Scopus SJRQ3Continuous contact problem of a functionally graded layer resting on an elastic half-plane
Öner, E.; Adiyaman, G.; Birinci, A.
In this study, the continuous contact problem of a functionally graded layer resting on an elastic half-plane and loaded by a rigid rectangular stamp is examined. The problem is solved assuming that the functionally graded (FG) layer is isotropic and the shear modulus and mass density vary exponentially throughout the layer's thickness. However, the body force of the elastic half-plane is neglected. In addition, it is assumed that all surfaces are frictionless and only compressive stress is transferred along the contact surfaces. The mathematical problem is reduced to a singular integral equation in which the contact stress under the rigid stamp is unknown using the Fourier integral transform and boundary conditions related to the problem. This singular integral equation is solved numerically using the Gauss-Chebyshev integration formula. The dimensionless contact stress under the rigid stamp, the initial separation loads and the initial separation distances between the FG layer and the elastic half-plane are obtained for various dimensionless quantities.
AtıfScopus26İncele - BildiriYayıncıda açık erişim2016Scopus SJRQ4Exergy analysis of a combined power and cooling cycle
Karaali, R.
Ammonia-water power cycles are important for efficient utilization of low temperature heat sources such as geothermal, solar, waste heat sources, etc. For some special conditions ammonia-water power cycle is an important and economical option. This paper presents an exergetic analysis of a combined power and cooling cycle that uses ammonia-water mixture as working fluid. Such cycles, use solar or geothermal energy or waste heat energy from a conventional power cycle. Ammonia-water power cycle can be used as independent cycles to provide power output and cooling. For a range (25-55 Bar) of boiler pressure the performance of the combined power and cooling cycle is investigated. The exergy of the boiler is very low compared to its energy. There is a boiling process and a heat transfer process at low temperature, both of which destruct the energy given to the boiler, so that the energy efficiency is low; however the exergy efficiency is higher than the energy efficiency. Increasing the turbine inlet pressure decreases the energy and exergy efficiencies.
AtıfScopus13WoS12OpenAlex75İncele - BildiriAçık Erişim2016Scopus SJRQ4Thermodynamic analysis of a cascade refrigeration system
Karaali, R.
There is a need for cooling by using the waste heat energy in food industry. Absorption cycles can be driven by waste thermal, geothermal, solar or industrial processes energies. In this study, cascade refrigeration system is thermodynamically modeled, and analyzed by using first law of thermodynamics, and exergy method. Thermodynamic properties such as pressure, temperature, entropy, enthalpy, exergy, mass flow rate in each stream are calculated for 50, 75, 100?C and for 0.8, 1.0, and 1.5 MPa pump pressure. A computer program is used that was prepared in FORTRAN by the author for the analyses. It is found that the compression-absorption cascade cooling cycle is appropriate for most of the kind of waste heat applications. Increase of the generator inlet heat temperature increases the generator inlet heat, the absorber outlet heat and the condenser 2 outlet heat energies and decreases the coefficient of performance of the absorption and the overall cycles. The generator heat decreases with increase of the pump pressure. Also increase of the pump pressure decreases the coefficient of performance of the absorption and the overall cycles. Increase of the pump pressure and the generator temperature decreases the exergetic coefficient of performance. Increase of the generator temperature and pump pressure increases the generator inlet exergy. It is concluded that increase of the generator temperature and the pump pressure increases the total destructed exergy of the cycle.
AtıfScopus10WoS5OpenAlex13İncele - DergiArchives of Mechanics