Mechanical Engineering / Makina Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4129

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Now showing 1 - 10 of 168
  • Article
    Citation - Scopus: 1
    Sizing of Autonomous Wind/Solar Hybrid Energy Conversion Systems for Urla, Turkey
    (ACTA Press, 2009) Özerdem, Barış; Ekren, Orhan
    In this paper, an optimum sizing procedure of autonomous hybrid (wind + solar) energy system is presented which can be used to satisfy the requirements of given load distribution. The main purpose of this study is to find out an appropriate wind-photovoltaic hybrid energy system to satisfy electricity consumption of GSM (Global System for Mobile communication) base station at Izmir Institute of Technology Campus Area, Urla, Izmir, Turkey. To do this, monthly average daily solar radiation and wind speed data are collected. The monthly average wind speeds are measured at 10 m height during 3 years period on Izmir Institute of Technology Campus Area. The monthly average wind speed values are obtained between 5.7 and 7.7 m/s, on the other hand, the monthly average daily value of solar radiations on horizontal surfaces are ranged from 1.4 to 6.9kWh/m2 at Izmir Institute of Technology Campus Area. The hybrid system considered in the present analysis consists of one 5kW nominal power wind energy conversion systems (WECS), 21.82 m2 of photovoltaic (PV) panels (18 mono crystal PV panels each having 75 W power output) together with a battery storage system.
  • Conference Object
    Cash Flow Forecasting by Using Time Series Methods in Geothermal District Heating Systems: Balcova - Narlidere Case
    (National Technical University of Athens, 2006) Erdoğmuş, Abdullah Berkan; Özerdem, Barış
    Cash flow forecasting is one of the difficult and important tasks in an economic evaluation of a geothermal investment. Geothermal district heating systems are characterized by a high capital cost. In addition, relatively low operation and maintenance costs occur throughout their life. The aim of this research is to estimate the potential cash flows for Balcova - Narlidere Geothermal District Heating System by using historical data accumulated over a period of time and several forecasting methods: moving average, exponential smoothing, adjusted exponential smoothing and curve fitting functions. Mean absolute percentage deviation (MAPD) which is the most common approach to select the appropriate method to a particular time series is used in the selection of the most suitable model. Alternative methods are compared with each other regarding to their MAPD values. It is found that the models represented by exponential curve fitting functions have smaller MAPD values and give better results in cash flow forecasting of investment investigated.
  • Conference Object
    Underground Gasification in Western Black Sea Area and Thermodynamic Analysis
    (2006) Atagündüz, Gürbüz
    As known, western Black Sea carboniferous coal fields consist of two main fields: Zonguldak and Amasra. Previous research works have shown that Zonguldak area is not suitable for underground coal gasification. The joint studies done since 1994 by the Department of Geology and the Solar Energy Institute of Aegean University and, the Mineral Research and Exploration Institute of Ministry of Energy and Natural Sources have shown that the Amasra coal field is suitable with certain restrictions for the underground coal gasification. In the present work, the suitability of the Amasra - coal field for underground coal gasification will be discussed and the "Controlled Retraction of the Injection Point; CRIP"- Method which was successfully used and tested in the American field experiments will be described briefly. A brief thermodynamic analysis of the gasification process will be given which should help, as a tool, to the theoretical prediction of the underground coal gasification.
  • Conference Object
    Energy Losses From Outdoor Located Air Handling Unit and Connection Duct
    (Universita degli Studi di Padova, 2007) Erdoğmuş, Abdullah Berkan; Mobedi, Moghtada; Özerdem, Barış
    In the present study, energy losses due to heat transmission and air leakage from outdoor located air handling unit and connection duct are investigated based on EN 1886 and NEN-EN 1507 standard. The EN 1886 standard classifies air handling unit according to heat transmission and air leakage, while NEN-EN 1507 standard specify air leakages of rectangular ducts. In this study, air leakage and heat transmission fluxes for three cities in different regions of Turkey are determined and the economical value of energy losses for a building located in the city of Izmir and services 24 hours is calculated. The ambient air temperatures are taken from Turkish State Meteorological Service. The daily average values are considered for ambient temperature. The energy losses are determined for the variable and constant supply temperatures. Tables and charts are provided to show the variation of energy losses due to transmission and air leakage for the whole year. The total amounts of heat transmission and air leakage energy losses for different classes of air handling unit and connection duct are compared and discussed.
  • Conference Object
    Tıbbi Uygulamalar için Özgün Yapılı Haptik Cihaz Tasarımı
    (Institute of Electrical and Electronics Engineers Inc., 2009) Selvi, Özgün; Bilgincan, Tunç; Kant, Yalkın; Dede, Mehmet İsmet Can
    Robotik sistemler hassasiyet gerektiren işlerde gün geçtilçe günlük hayatımızın bir parçası olmaya başladı. Bu işler genellikle herhangi bir operatör tarafından yapılamayacak kadar hassasiyet gerektiren işler olduğundan dolayı robotik teknolojiye ihtiyaç vardır. Bir robotik alanı olan Haptik teknolojisi, operatör ile çevrenin etkileşimini kuvvet geri beslemesi ile sağlayarak uygulamanın hassasiyet seviyesini arttırmaktadır. Bugünkü haliyle haptik teknoloji tıbbi operasyonlarda yardımcı sistem olarak ve birçok uzaktan kumandalı operasyonlarında (teleoperasyon) kullanılmaktadır. Aynı zamanda haptik teknoloji askeri ve tıbbi eğitim amaçlı sanal gerçeklik programlarında kullanılmaktadır. Bu çalışmanın amacı sistemin hassasiyetini arttırabilecek yapısal olarak yeni bir haptik cihaz tasarlamaktır. Bu kapsamda, önceden gerçekleştirilmiş robot tasarımları araştırıldı ve kavramsal tasarımlar gelistirildi. Sonuç olarak seçilen tasarım sanal ortam da oluşturuldu ve simülasyonu yapıldı, ve ilk prototipi imal edildi
  • Conference Object
    Si-Geothermometry Applied for the Interpretation of Three-Components Mixtures in Marine Geothermal Systems -Exploration of the Gülbahce Geothermal Field, Western Anatolia/ Turkey
    (Wydawnictwo Uczelniane Politechniki Szczecinskiej, 2000) Giese, L.B.; İlken, Zafer; Çetiner, Levent; Yıldırım, Nazım
    The geothermal field of Gülbahce is located in western Anatolia/Turkey near Izmir. The University of Izmir IYTE is building-up a campus there. A pre-study was done to investigate whether the campus can be supplied with geothermal heat. Based on hydrogeochemical data, mixing calculations and a modified version of the SiO2-enthalpy diagram were applied to evaluate the reservoir temperature of three-components-mixtures. The temperature of the mixed outcrop water is 35°C. It consists of geothermal sea water, freshwater, and cold sea water. The fraction of freshwater was estimated to be 8%, The contents of Li and Si were interpreted to be generated by the reservoir temperature of 60°C in minimum - lower limit for low-temperature space heating - but to be maybe more than 100°C. This geothermal resource seems to be suitable, but exploitation will be difficult. One production well should satisfy the heat supply. Problems with scaling and corrosion are expected.
  • Conference Object
    Citation - Scopus: 2
    Adaptive Actuator Failure Compensation for Concurrently Actuated Manipulators
    (Elsevier, 2003) Keçeci, Emin Faruk; Tang, Xidong; Tao, Gang
    This paper presents an adaptive actuator failure compensation method, which compensates for uncertainties due to unknown actuator failures and system dynamics, for a class of redundant manipulators where some joints concurrently actuated. Physical realization of concurrently actuated manipulators and their advantageous of use have been understood before, but adaptive failure compensation is still an open issue. In this research, failure formulation, controller structure and adaptive update rules for handling uncertainties from both the system dynamics and the failures are studied. The system stability is shown by a modified Lyapunov. Simulation results show the effectiveness of the proposed adaptive failure compensation control design.
  • Conference Object
    Adaptive Actuator Failure Compensation for Cooperating Multiple Manipulator Systems
    (Elsevier, 2003) Keçeci, Emin Faruk; Tang, Xidong; Tao, Gang
    This paper presents adaptive actuator failure compensation for a cooperating multiple manipulator system with uncertain actuator failures in the task space. Advantages of designing control schemes in task spaces are emphasized, applications of task space control in robotics are discussed and a short review on control algorithms for cooperating multiple manipulator systems is given. Dynamic equations of motion of the multiple manipulator system in the task space are derived, and the adaptive actuator failure compensation problem is formulated. A compensation controller structure is proposed, for which adaptive parameter update laws are developed. The adaptive control scheme is able to compensate for the uncertainties arising from both the system parameters and the actuator failures. Based on Lyapunov stability analysis, the closed-loop signal boundedness and the convergence of the tracking error to zero are ensured. © 2003 International Federation of Automatic Control.
  • Conference Object
    Citation - Scopus: 2
    Importance of Load Based Automatic Control in Geothermal Energy Systems
    (Elsevier, 2003) Şener, Adil Caner; Toksoy, Macit; Aksoy, Niyazi
    Geothermal energy production is not possible without use of electricity, since electricity is needed to pump geothermal fluid from underground to consumption point. The biggest portion of the operating cost in geothermal district heating systems comes from pumping energy consumption. In ibis study Balcova-Narhdere geothermal district heating system has been analysed and the optimum control strategies minimising the energy consumption in the system discussed. Then decisive factors in the efficient control and operation of geothermal healing systems have been studied. Finally fundamental automation requirements for efficient operation of geothermal district heating systems has been introduced. Copyright © 2003 IFAC.
  • Article
    Fireproofing the Firefighting Robot
    (Laurin Publishing Co. Inc., 2009) Keçeci, Emin Faruk
    Researchers at the Institute of Technology in Izmir, Turkey, have successfully developed a mechanical firefighter robot that will work inside the flames. The robot uses both passive and active cooling systems that, for a limited time, keep the inner temperature at a safe level for the electronic components inside the device, to survive the flame. The body of the robot is made of aluminum and comprises two shells attached to each other with rods. The robot is controlled with a remote unit by an operator, who can observe the fire via a CCD camera. Control and cooling subsystems will allow the robot to work in these rough conditions. The control system allows the robot to use the navigation system as well as the sensory and cooling systems. The robot will be controlled with radiofrequency communications and is able to break doors and climb stairs to work in upper-level fires.