Person: FEYZİOĞLU, AHMET
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
FEYZİOĞLU
First Name
AHMET
Name
6 results
Search Results
Now showing 1 - 6 of 6
Publication Open Access Beef Quality Classification with Reduced E-Nose Data Features According to Beef Cut Types(2023-02-01) FEYZİOĞLU, AHMET; Feyzioglu A., Taspinar Y. S.Ensuring safe food supplies has recently become a serious problem all over the world. Controlling the quality, spoilage, and standing time for products with a short shelf life is a quite difficult problem. However, electronic noses can make all these controls possible. In this study, which aims to develop a different approach to the solution of this problem, electronic nose data obtained from 12 different beef cuts were classified. In the dataset, there are four classes (1: excellent, 2: good, 3: acceptable, and 4: spoiled) indicating beef quality. The classifications were performed separately for each cut and all cut shapes. The ANOVA method was used to determine the active features in the dataset with data for 12 features. The same classification processes were carried out by using the three active features selected by the ANOVA method. Three different machine learning methods, Artificial Neural Network, K Nearest Neighbor, and Logistic Regression, which are frequently used in the literature, were used in classifications. In the experimental studies, a classification accuracy of 100% was obtained as a result of the classification performed with ANN using the data obtained by combining all the tables in the dataset.Publication Open Access A study on the control system of electric water heaters for decarbonization(2023-03-01) FEYZİOĞLU, AHMET; Feyzioğlu A.Greenhouse gas (GHG) emissions have significantly increased in recent years as a result of population rise and the increase in the number of residences, with high levels of energy use in homes and household appliances. It is crucial to move the housing industry away from high-carbon sources and toward low-carbon sources in order to minimize greenhouse gas emissions as a precaution. One of the most crucial systems that needs to be provided in order to achieve energy efficiency is the electric water heater (EWH), as they rank among the top electricity consumers. In this study, a double-tank EWH model was developed and simulated at various tank sizes (100 L, 200 L, 300 L and 400 L) and power ratios (1 kW, 2 kW, 3kW and 4 kW) in order to demonstrate energy efficiency. To obtain information for the simulation analysis of the tanks, the hourly water usage of 25 houses was measured. The single-tank and the double-tank models created for this study were both run in the Matlab/Simulink environment with an on-off controller applied, and their energy consumption was compared. Amounts were also determined based on how much energy both tanks consumed. It has been noted that the amount of GHG emissions is also reduced because the double tank uses less energy than the single tank does. The simulation showed that compared to the single tank, the dual tank produced 46.62% less GHG emissions at 45 W power and 47.51% less GHG emissions at 80 W.Publication Open Access Numerical analysis of multipurpose shell-tube-heat exchanger withal stylized geometry at different baffle gaps and various flow rates(2023-12-01) FEYZİOĞLU, AHMET; Kartal D. M. A., Feyzioğlu A.The effects of changing 90 mm and 110 mm plate spacings and FR factor of 0.9 kg/h, 1.3 kg/h, 1.7 kg/h, 1.9 kg/h on the total heat transfer performance and PD in the new design HX were examined. The results obtained by taking into account the change in plate spacing and FR factor of 0.9 kg/h, 1.3 kg/h, 1.7 kg/h and 1.9 kg/h, as well as variable factors, were transferred to the study and displayed in figures. In the study, firstly, the results of HCO obtained by changing FR and range were monitored. In the analysis, the interval values were 90 mm and 110 mm and the changes in the FR values of 0.9 kg/h, 1.3 kg/h, 1.7 kg/h and 1.9 kg/h increased in direct proportion. The smallest value of the heat transfer rate was obtained at 110 mm plate spacing and 0.9 kg/h FR. In addition, if the plate spacing was 90 mm, the smallest HCO was obtained at 0.9 kg/h. The largest HCO was obtained when the plate spacing was 90 mm and FR was 1.9 kg/h. In the second part of the study, the results of PD obtained by changing FR and gap were monitored. In the analysis, the interval values were 90 mm and 110 mm and the changes in FR values of 0.9 kg/h, 1.3 kg/h, 1.7 kg/h and 1.9 kg/h increased in direct proportion. The smallest value of PD level was obtained at 90 mm plate spacing and 0.9 kg/h FR. In addition, if the plate spacing was 110 mm, the smallest heat transfer coefficient was obtained at 0.9 kg/h. The largest PD value was obtained when the plate spacing was 110 mm and FR was 1.9 kg/h. In the last part of the study, the results obtained by changing FR and range of the HTPD value were monitored. In the analysis, the interval values were 90 mm and 110 mm, and the changes in FR values of 0.9 kg/h, 1.3 kg/h, 1.7 kg/h and 1.9 kg/h decreased in direct proportion. The smallest value of the HTPD level was obtained at 110 mm plate spacing and 1.9 kg/h FR. In addition, if the plate spacing was 90 mm, the smallest HTPD value was obtained at 1.9 kg/h. The highest HTPD value was obtained when the plate spacing was 90 mm and FR was 0.9 kg/h. Therefore, choosing a system with a 90 mm plate spacing and a FR of 0.9 kg/h will be more efficient in terms of thermohydraulic performance and pressure balancing. As a result, it was concluded that if the plate spacing was selected as 90 mm, a 15 % improvement could be achieved compared to the system design with a 110 mm plate spacing. As a new, it is thought that it will contribute to the literature in future studies, as the thermal performance, pressure drop and heat transfer coefficient results obtained at new flow rate values and compartment spacing values are obtained for the first time in a new STH designed in different dimensions than the literature.Publication Metadata only Experimental comparison and numerical heat analysis of newly designed shell-and-tube heat exchanger with designed geometry at different baffle intervals: status of energy efficiency(2024-01-01) FEYZİOĞLU, AHMET; Kartal M. A., FEYZİOĞLU A.Optimizing the performance of the heat exchanger to increase the heat capacity while reducing the pressure drop is determined as the most important design goal. Three main designs of heat exchangers are made according to parallel flow, counter flow and cross flow arrangement. The heat exchanger used here is chosen as a parallel flow heat exchanger. The aim of this study is to investigate heat transfer, the energy efficiency and thermal performance changes on the fluid behavior of varying baffle spacings at different flow rates in a parallel flow shell-and-tube heat exchanger. Water with a density of 976.1 kg/m3 was used as the fluid in the analyses. Other thermophysical properties of water are as follows: cp, 4191.5 J/kg °C; m, 0.000391 kg/m s; K, 0.665 W/m °C. It has been observed that the energy efficiency and thermal performance values of the fluid differ with the change of the baffle intervals Bd1 = 80 mm, Bd2 = 120 mm and flow rates between Fr1 = 0.1 kg/h and Fr100 = 10.0 kg/h used in the newly designed shell-and-tube heat exchanger.Publication Open Access Numerical Analysis of Altered Parallel Flow Heat Exchanger with Promoted Geometry at Multifarious Baffle Prolongs(2024-04-01) FEYZİOĞLU, AHMET; Kartal M. A., Feyzioğlu A.This study investigated the influence of BFFSP on the thermohydraulic performance of a SATHEC(s) using a novel computational approach. The novelty lies in the detailed exploration of the interplay between BFFSP, MFRT, and key performance parameters. Unlike prior studies, which often focus on a limited range of operating conditions, this work employs a comprehensive parametric analysis encompassing two BFFSPs (95 mm and 125 mm) and four MFRTs (0.1, 0.3, 0.5, and 0.7 kg/h). This extensive analysis provides a deeper understanding of the trade-off between the HTRFR enhancement and PDP associated with the BFFSP across a wider range of operating conditions. This investigation leverages the power of computational fluid dynamics (CFD) simulations for highfidelity analysis. ANSYS Fluent, a widely recognized commercial CFD software package, was used as a computational platform. A three-dimensional steady-state model of HEXR geometry was established. The cold fluid was modeled as water, and the hot fluid was modeled as water. The selection of appropriate turbulence models is crucial for accurate flow simulations within the complex geometry of HEXR. This study incorporates a well-established two-equation turbulence model to effectively capture turbulent flow behavior. The governing equations for mass, momentum, and energy conservation were solved numerically within the CFD framework. Convergence criteria were meticulously established to ensure the accuracy and reliability of the simulation results. BFFs are crucial components in HEXRs as they promote fluid mixing and turbulence on the HTRFR surface, thereby enhancing HTRFR. This study explores the interplay between BFFSP and HTRFR effectiveness. It is hypothesized that a larger BFFSP (125 mm) might lead to a higher HTC owing to the increased fluid mixing. However, the potential drawbacks of the increased PDP due to the flow restriction also need to be considered. The PDP across the HEXR is a critical parameter that affects pumping costs and overall system yield. This study investigates the impact of BFFSP on the PDP. It is expected that a larger BFFSP (125 mm) will result in a higher PDP, owing to the increased resistance to fluid flow. Here, we aim to quantify the trade-off between enhanced HTRFR and increased PDP associated with different BFFSPs. The optimal design of an HEXR seeks a balance between achieving a high HTRFR rate and minimizing pressure losses. HTRPD, a metric combining both HTC and PDP, was employed to evaluate the thermohydraulic performance. We hypothesized that a specific BFFSP might offer a superior HTRPD, indicating an optimal balance between HTRFR effectiveness and PDP for the investigated HEXR geometry and operating conditions. CFD simulations were conducted using ANSYS Fluent to analyze the effects of BFFSP and MFRT on the HTC, PDP, and HTRPD. The simulations employed a commercially available HEXR geometry with water as the cold and hot fluid. The results are presented and discussed to elucidate the relationships between the BFFSP, MFRT, and key performance parameters of the HEXR. This study provides valuable insights into the influence of BFFSP on the thermohydraulic performance of HEXRs. The findings can aid in optimizing the HEXR design by identifying the BFFSP that offers the best compromise between HTRFR enhancement and PDP for specific operating conditions. The results contribute to the knowledge base of HEXR design and optimization, potentially leading to improved yield in various industrial applications. The results indicate that a larger BFFSP (125 mm) leads to higher outlet temperatures but also results in a higher PDP compared to the 95 mm design. Conversely, the 95 mm BFFSP exhibits a lower PDP but achieves a lower HTC. In terms of thermohydraulic performance, as indicated by HTRPD, the 95 mm BFFSP with the lowest MFRT (0.1 kg/h) achieved the highest value, surpassing the 125 mm design by 19.81%. This suggests that a 95 mm BFFSP offers a better trade-off between HTRFR effectiveness and pressure loss, potentially improving the overall HEXR performance.Publication Metadata only Detection of defects in rolled stainless steel plates by machine learning models(2023-03-01) FEYZİOĞLU, AHMET; Feyzioğlu A., Taşpınar Y. S.