Energy Systems

Energy Systems

Energy Systems
Serhat Yeşilyurt
  • Polymer Electrolyte Membrane Fuel Cell (PEMFC)
    Distribution of the hydrogen mole fraction in the new design"

    Owing to high energy efficiency and density, polymer electrolyte membrane fuel cells (PEMFC) are very attractive for transportation and stationary applications. However, commercialization of the PEMFC technology is hindered by problems such as high cost, complexity of the system, and durability of the polymer membrane, electrode and catalyst materials. Our research aims to design and develop PEMFCs that operate with high hydrogen utilization with fewer parts in the overall system. In a current project funded by TUBITAK, we are developing a PEMFC that consists of approximately 10 cells with a large active area (approximately 400 cm2), delivers about 3 kW at ultra-low stoichiometric flows at the anode exit. Computational models are used to design flow and cooling channels, which are appropriate for these operating conditions and the thermal management system.

  • Vertical Axis Wind Turbine (VAWT)
    Installation of the experimental test-bed by research personnel in SU campus.

    In the presence of ever visible effects of global climate change, small scale wind turbines are considered as viable renewable systems. Small scale vertical axis wind turbines (VAWT) can be used as power supplies for telecommunication towers, recreational and military camps away from the population. Moreover silent and aesthetic VAWT prototypes are attractive for urban use as well. The VAWT design that we are working on has the following features: an efficient blade profile and the chord length obtained from CFD simulations coupled with the dynamics of the rotor; blades that are made of cheap light-weight and durable composite materials for; and a model-based controller for maximum energy generation for given wind conditions. Generic turbulence models such as k-epsilon and k-omega are used in the time-dependent two-dimensional CFD models coupled with the dynamics and control of the rotor to obtain an optimum design. The profiles that satisfy aerodynamic efficiency requirements are built from shell-spar-foam type composite materials. Static and dynamic structural analysis of the blades and other components of the rotor such as the shaft and the arms are conducted to obtain appropriate profiles of the beams used in the design.