ISSN Online: 2377-424X
ISBN Print: 0-89116-559-2
International Heat Transfer Conference 8
TRANSIENT CROSS-FLOW MIXED CONVECTION ADJACENT TO AN ISOTHERMAL VERTICAL PLATE IN AIR
Resumo
Numerically calculated flow and temperature fields are presented for transient laminar mixed convection in air near a vertical heated surface exposed to a horizontal cross-flow. The transients considered include the simultaneous starting of flow and heating, as well as the case when a forced flow is imposed on an already established natural convection boundary layer. With the cross-flow present, the time to reach steady state was found to be much shorter than for the corresponding natural convection flow. The cross flow also produces a significant increase in the local heat transfer coefficient, compared with pure natural convection flow, throughout the transient. For the transient initiated by suddenly imposing a horizontal forced flow on an existing natural convection flow, the local temperature and vertical velocity were found to undershoot before reaching their respective steady-state values. This undershoot produces a substantial overshoot in the local heat transfer coefficient which increases with increasing distance from the vertical leading edge. For both transients, forced flow effects were found to dominate near the vertical leading edge, whereas buoyancy effects dominate at large values of the horizontal coordinate.