Person:
KARAGÖZ, İRFAN

Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

OrgUnit Logo
Organizational Unit

Job Title

Last Name

KARAGÖZ

First Name

İRFAN

Name

Filters

20212
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Numerical investigation of heat and flow characteristics in a laminar flow past two tandem cylinders
    (Vinca Inst Nuclear Sci, 2021-01-01) Aydın, Neslihan; Özalp, Alper; Karagöz, İrfan; AYDIN, NESLİHAN; ÖZALP, ABDURRAHMAN ALPER; KARAGÖZ, İRFAN; 0000-0002-7442-2746; AAB-9388-2020; AAB-9496-2022
    Heat and flow characteristics were investigated numerically for a laminar stream past two tandem circular cylinders placed in a channel. The blockage ratios (beta = D/H) were chosen to be 0.6, 0.7, and 0.8, respectively, and the gap between the cylinders was varied proportionally to the cylinder diameter as g = 0.2D, 0.7D, 1.5D, and 4D at a low Reynolds number (Re = 40). The effects of the blockage ratio, as well as the gap between two cylinders on heat and flow features were examined in detail. Shear stresses, dimensionless static pressure, heat transfer coefficient, and separation points from the cylinders were determined from the velocity and temperature fields in the flow domain. The results showed that the separation angle decreases with both the blockage ratio and the gap size on the downstream cylinder, whereas heat transfer increases with both the blockage ratio and the gap size on the upstream cylinder.
  • Thumbnail Image
    Publication
    Response of a proton exchange membrane fuel cell to step changes in mass flow rates
    (Wiley-v C H, 2021-06-20) Küpeli, Seda; Çelik, Erman; Karagöz, Irfan; Karagöz, Irfan; KARAGÖZ, İRFAN; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Makine Mühendisliği Bölümü.; 0000-0002-7442-2746; JCN-7685-2023; AAB-9388-2020
    Transient regime effects are particularly important in fuel cells designed for vehicles. Three-dimensional modeling of a proton exchange membrane fuel cell with a serpentine channel is presented, and the response of the fuel cell to a step-change in the mass flow rates is analyzed by using the computational fluid dynamics techniques. After a validation study of the mathematical and numerical model, step increases of 20% in mass flow rates are applied to the inlet boundary conditions, and time dependent power and current density responses of the fuel cell are analyzed. Polarization curves are generated for the assessment of the fuel cell performance, and their variations in time are presented. The results show that current and power densities increase with time at low cell voltage values due to concentration losses; however, increases in power and current are negligible at high voltages.