Turbulent Free Convection Heat Transfer from Vertical Parallel Plates : Effect of Entrance Bell-Mouth Shape

Abstract

The streamwise development of turbulence in the free convection flow between vertical parallel plates (5m long and various spacings B) was experimentally studied. To control inlet disturbance, a bell-mouth entrance was installed at the lower end of the vertical parallel plate channel. The turbulent quantity profiles (velocity, intensity, turbulent heat flux and kinetic energy production) were measured in the vertical channel at heights X (110, 820, 1690, 2630 and 3840mm) and at spacings B of 50, 100 and 200mm. The streamwise development of intensity profiles of vertical velocity and the beginning of the transition seem to be closely related to the development vertical velocity profiles through buoyancy effects. The measured profiles of the turbulent kinetic energy production and the turbulent heat fluxes seem to clarify the characteristics of turbulence intensity.