Numerical Study of the Effects of a Hot Obstacle on Natural Convection Flow Regimes

A numerical study was conducted for natural turbulent and laminar convection induced by a circular hot obstacle in two different positions, the heat is introduced at inlet of cylinder inside cylinder. To determine effects on regime thermosiphon flow generated heated cylindrical channel, we suggest theoretical model using Navier–Stokes equations finite volume method. An experimental apparatus used validation model. comparison results showed good agreement global behavior. The temperature vertical velocity profiles demonstrated presence boundary-layer along channel's wall absence positions. introduction generates significant modification evolution above obstacle. simulation specific radius that ensures existence regime, Rayleigh numbers (Ra=105; 107; 108; 109; and1010). rate, velocity, Nusselt number were presented discussed. are our maxima component profile. profile entrance appearance maximum As height increases, air decreases. displacement upward induces behavior dynamical flow. CFD code to regimes three form factors, including critical with factor A=0.1.