Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2010Numerical analysis of entropy generation in concentric curved annular ducts
Kucuk, Haydar
The entropy generation has been numerically investigated in concentric curved annular square ducts under constant wall temperature boundary condition. The problem has been assumed to be steady, hydrodynamically and thermally fully developed and incompressible laminar flow with constant physical properties. The solutions of discretized equations for continuity, momentum and energy have been obtained by using an elliptic Fortran Program based on the SIMPLE algorithm. Solutions have been achieved for i) Dean numbers ranging from 3.6 to 207.1, ii) Annulus dimension ratios of 5.5, 3.8, 2.9 and 2.36, and iii) Prandtl number of 0.7. In this regard, local entropy generation as well as overall entropy generation in the whole flow field has been analyzed in detail. Moreover, the effects of Dean number and annulus dimension ratio on entropy generation arising from the friction and heat transfer have been investigated. Accordingly, it is concluded that the effect of volumetric entropy generation that is a result of fluid frictional irreversibility can be neglected as compared with volumetric entropy generation due to heat transfer irreversibility. As Dean number increases, the distribution of volumetric entropy generation coming out from the heat transfer irreversibility is formed by the temperature field, which is depending on the curvature.
- MakaleAçık Erişim2010Economic analysis and sustainability of Turkish marine hatcheries; [Türkiye Deniz Balıkları Kuluçkahanelerinin Ekonomik Analizi ve Sürdürülebilirliǧi]
Kurtoglu, Ilker Zeki; Kucuk, Haydar; Alkan, Ali; Özdemir, Atilla
The economic analysis was performed and sustainability was evaluated for 7 leader Turkish marine hatcheries which have 61.5% of Turkish total marine fish fry production. For this purpose, the fixed cost including investment and operational costs including feed, labor, energy, fuel, water, oxygen, and medicament costs were determined by face to face interview for each hatchery. Also, production methods, species cultured and marketing techniques of each hatchery were investigated and conflicts, opportunities, projections, structuring and sustainability of the sector were evaluated by questionnaire designed in the scope of SUSTAINAQ, a FP6 Project supported by EU. As a result, it was seen that the ratio of total cost to total income changed between 22% and 97.8%. Although the RAS requires high operation and initial investment costs and highly qualified technicians, it is seen that it will be very important for sustainability of Turkish marine hatcheries because of land, quality and quantity of water and environmental approaches.
- MakaleYalnız künye2010Exergetic performance analysis of a recirculating aquaculture system
Kucuk, Haydar; Midilli, Adnan; Özdemir, Atilla; Çakmak, Eyüp; Dincer, Ibrahim
This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period.