An experimental study of a heated circular stack emitting into a crossflow

The velocity and temperature characteristics of a heated jet emitting from a raised circular stack into a cross°ow are documented for T _stack=T_∞ = 1:25, U_stack=U _∞ = 2 and a blowing ratio, r = [(ρU²)stack= (ρU²)_∞]^1/2, of 1.79. Point-wise temperature measurements with thermocouples are used to reconstruct mean temperature fields at various locations downstream of the stack while particle image velocimetry (PIV) measurements of instantaneous velocity fields along the spanwise centerline of the stack are used to assess the flow development in the near-stack region. The temperature of the hot jet core diminishes quickly with downstream distance, most likely because of significant entrainment of cooler ambient fluid into the jet core by the turbulent structures that dominate the downstream development of the jet. These results also highlight the dominance of downstream advection of the heated jet by the free-stream with little influence of buoyancy evident in the jet's downstream development. The mean velocity field downstream of the emitted jet is marked by a strong recirculation region due to "blockage" of the free-stream by the vertical jet emitting into the cross flow. In addition, strong turbulence is noted on the downstream side of the heated jet due to the occurrence of intense vortical structures.