Yazarlar

• Ashyralyev, A(1)
• Aydin, O.(1)
• Aydin, Orhan(1)
• Gedikli, Hasan(1)
• Küçük, Haydar(1)
• Malkowsky, E(1)
• Saglam, M.(1)
• Saglam, Mehmet(1)
• Sahin, Birol(1)
• Sarper, B.(1)
• Sarper, Bugra(1)

• MakaleYalnız künye2018/r/gumushane/15328
  Experimental and numerical investigation of natural convection in a discretely heated vertical channel: Effect of the blockage ratio of the heat sources

  Sarper, Bugra; Saglam, Mehmet; Aydin, Orhan

  This study deals with the buoyancy induced flow and heat transfer in a parallel plate channel with a heat source array, which simulates an electronic package. The heat source array consists of four discrete protruding heat sources made of copper. The focus of this study is concentrated on the effect of heat source blockage ratio (br) on recirculating flow and cooling performance of the system. Studies are conducted both for flush mounted or protruding heat source cases. Four different values of the blockage ratio of the protruding heat sources (br = 0.125, 0.25, 0.375 and 0.5) are considered. The range of the modified Grashof number covers the values between 9.6 × 105 and 1.53 × 107. In the experiments, flow visualization and temperature measurements are conducted. Numerical studies are performed via ANSYS Fluent software. From the experimental results and numerical studies, it is found that buoyancy induced flow and cooling performance is significantly affected by the blockage ratio of the heat source array.

  İncele
• MakaleAçık Erişim2018/r/gumushane/11338
  Natural convection in an enclosure with a discretely heated sidewall: Heatlines and flow visualization

  Saglam, M.; Sarper, B.; Aydin, O.

  Natural convection inside a rectangular enclosure is investigated experimentally and numerically. One of the sidewalls is heated discretely by two flush-mounted heat sources. The other sidewall is kept at a constant temperature, while the horizontal walls are unheated. Heat dissipation rates of the heat sources are equal to each other. The aspect ratio of the enclosure (AR) is 2 and the working fluid is air (Pr=0.71). The study is focused on the validation of the two and three dimensional computations under real test conditions against experiments for various modified Rayleigh number values. Experimental study is performed for various modified Rayleigh numbers in the range of 7.7×105 and 3.1×106 while numerical part covers the values between 104 and 5×106. Temperature measurements and flow visualization studies are performed in the experimental work, and streamlines, isotherms and heatlines are presented in the numerical part of the study. From the experimental and numerical studies, it is shown that two dimensional computations reflects the general characteristics of the problem, conduction and radiation heat transfer are not negligible, surface temperatures increase with the modified Rayleigh number and heatline approach is an important tool to analyze convective heat transfer.

  İncele
• BildiriYalnız künye2014/r/gumushane/15780
  Effects of discretization schemes on numerical results of natural convection heat transfer

  Sahin, Birol; Ashyralyev, A; Malkowsky, E

  Two dimensional natural convection heat transfer in a square enclosure is numerically analyzed. Laminar naturalconvection heat transfer is studied by solving the Navier-Stokes and energy equations using finite volume method. Numerical solutions of flow field are obtained by Semi-Implicit Method for Pressure-Linked Equations (SIMPLE). Effects of the discretization schemes on numerical solutions are compared with each other.

  İncele
• MakaleYalnız künye2010/r/gumushane/15506
  Natural convection in a triangular cross section roof under daylight conditions

  Küçük, Haydar; Gedikli, Hasan

  The natural convection is numerically investigated in a roof of triangular cross section under constant heat flux with seven different values depending on daylight on the inclined wall, constant wall temperature on the bottom wall and adiabatic on the vertical wall boundary conditions. Continuity, momentum and energy equations are solved by using fmite volume method for laminar, two-dimensional and steady-state regime. Streamlines, isothenns, local and mean Nusselt numbers are p̧resented for AR=0.25, 0.5, 0.75 and 1.0 and Ra=103, 104, 105, 106. The amount of heat flux ranges from 163 W/m2 to 808 W/m2 depending on daylight and the Prandtl number is chosen as 0.7. It is found out that the aspect ratio and Rayleigh number highly affect the heat transfer on the bottom and inclined walls while heat flux slightly affects.

  İncele