Yazar "Akansu, Selahaddin Orhan" seçeneğine göre listele

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    Experimental and numerical aerodynamic investigation of a prototype vehicle
    (TECHNO-PRESS, 2015) Akansu, Selahaddin Orhan; Akansu, Yahya Erkan; Dagdevir, Toygun; Daldaban, Ferhat; Yavas, Feridun
    This study presents experimental and numerical aerodynamic investigation of a prototype vehicle. Aerodynamics forces examined which exerted on a prototype. This experimental study was implemented in a wind tunnel for the Reynolds number between 105-3.1x10(5). Numerical aerodynamic analysis of the vehicle is conducted for different Reynolds number by using FLUENT CFD software, with the k-epsilon realizable turbulence model. The studied model aims at verifying the aerodynamic forces between experimental and numerical results. After the Reynolds number of 2.8x10(5), the drag coefficient obtained experimentally becomes independent of Reynolds number and has a value of 0.25.
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    Investigation of S1046 profile bladed vertical axis wind turbine and artificial intelligence-based performance evaluation
    (Taylor & Francis Inc, 2023) Osmanli, Suleyman; Akansu, Selahaddin Orhan; Azginoglu, Nuh; Akansu, Yahya Erkan; Develi, Ibrahim
    It is very important to determine the parameters affecting the performance of the Darrieus-type wind turbine and its effects. In particular, it should be specified at which TSR value the peak power coefficient is obtained. In this study, standard and modified S1046 airfoils and aspect ratios (H/D), angle of attack (AoA), turbulent/non-turbulent flow (WT), number of blades (N), and chord length (C) were tested. Then, four different machines learning-based multi-output regression models (Decision Tree, Linear Regression, K-Nearest Neighbors, and Random Forest) were trained to make performance predictions with the data obtained from the evaluated test setup. Thirdly, feature selection based on the Random Forest algorithm, which is the best performing multi-output regression model, was performed using data due to changing parameter values on the established system. The importance of the parameters was determined. The operating range of the system was at relatively low TSR values. When analyzing the blade profile, the modified blade version performed better in certain combinations compared to the standard profile. Maximum power coefficient (Cp) was obtained from the modified turbine structure with 5 degrees of attack angle, H/D = 1.85, and C = 60 mm. The present study aims to increase the turbine's power coefficient and aims to predict results as power coefficient without doing many different experiments.
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    Performance analysis of Savonius wind turbines in different models
    (Sage Publications Ltd, 2022) Simsek, Ayse; Teksin, Suleyman; Akansu, Selahaddin Orhan; Akansu, Yahya Erkan
    This study presents experimental results of power performance characterizations for of 12 different Savonius turbine blades. There are three different models and the numbers of each blade types have been selected as 2, 3, 4, and 5. Three different blade types are drawn in a CAD program and all blade models are produced from 3D printer. The experiments are carried out in the subsonic wind tunnel laboratory of the Faculty of Aeronautics and Astronautics at Erciyes University. The wind tunnel has 15 kW motor power to produce wind flow. Test zone inlet and outlet section is 0.57 m x 0.57 m and 0.59 m x 0.59 m respectively. Shaft to shaft type torque meter is mounted between turbine and electric motor. Measurements have been made at wind speeds between 1 and 30 m/s. The performance values of each turbine have been measured. While the 3-bladed turbine showed the highest power coefficient values in the whole study, the maximum value was obtained from the modified helical turbine type.
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    Performance prediction of PEM fuel cell with wavy serpentine flow channel by using artificial neural network
    (Pergamon-Elsevier Science Ltd, 2017) Seyhan, Mehmet; Akansu, Yahya Erkan; Murat, Mirac; Korkmaz, Yusuf; Akansu, Selahaddin Orhan
    Effects of serpentine flow channel having sinusoidal wave at the rib surface on performance of PEMFC having 25 cm(2) active area are investigated at different flow rates, three different amplitudes changing from 0.25 mm to 0.75 mm and three different cell operation temperatures. A proton exchange membrane fuel cell (PEMFC) is modeled for the prediction of the output current by using artificial neural network (ANN) that is utilized the aforementioned experimental parameters. Effect of hydrogen and air flow rate, the fuel cell temperature, amplitude of channel is tested. The results indicated that model C1 having lowest amplitude is enhanced maximum power output up to 20.15% as compared to indicated conventional serpentine channel (model C4) for 0.7 SLPM H-2 and 1.5 SLPM air and also model C1 has better performance than C2, C3 and C4 models. The maximum power output is augmented with increasing the cell temperature due to raising the fuel and oxidant diffusion ratio. Cell temperature, amplitude, H2 and air flow rate and input voltage is used as input variables in train and test of the developing ANN model. MAPE of training and testing is determined as 239 and 2.059, respectively. Prediction results of developed ANN model including two hidden layer shows similar trend with experimental results. Developed ANN model can be used to both decrease the number of required experiments and find the optimum operation condition within the range of input parameters. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
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    THE EFFECT OF USING ACTIVATED CARBON OBTAINED FROM SEWAGE SLUDGE AS A FUEL ADDITIVE ON ENGINE PERFORMANCE AND EMISSIONS
    (Vinca Inst Nuclear Sci, 2023) Bilgin, Serhat; Onal, Yunus; Akansu, Selahaddin Orhan; Ilhak, Mehmet Ilhan
    The increasing need for clean water depending on the world's population has accelerated efforts to re-evaluate the use of water. This has led to the spread of wastewater treatment plants (WWTP). Sewage sludge (SS), which is the waste of WWTP, is increasing due to the increase in the number of plants. As a result, the disposal and evaluation of SS, which is waste, has accelerated. In this study, researches were carried out on different usage areas of SS, which is WWTP waste. The SS was first dried. After the drying process, the SS was subjected to physical and chemical activation processes and turned into activated carbon. Activated carbons were obtained at different operating temperatures. The FT-IR, XRD, ICP-MS, TG-DTA, CHNS, SEM-EDX analyzes were performed for the obtained activated carbons. According to the results of the analysis, the selected activated carbons were mixed with diesel fuel at 50 ppm and 100 ppm ratios. The effects of fuel mixtures prepared with diesel fuel in terms of engine performance, combustion and emissions are investigated. Engine performance and exhaust emission measurements were made in a 6-cylinder Diesel engine at a constant speed of 600 rpm and under five different loads (0 Nm, 50 Nm, 100 Nm, 150 Nm, and 200 Nm). Emission values were measured as CO, HC, CO2, O-2, and NOx and comparative assessments were made. In this study, the positive effects of SS-derived activated carbons on the engine were determined by using it as a diesel fuel additive.