The development of low Reynolds number channel flow during mixed convection has been investigated experimentally. The measurements were taken at five different locations along the heating section of the channel. The experiments were conducted at bottom wall temperatures of 35, 45 and 55 (°C) at a flow rate of 0.0315 kg/s (corresponding to the unheated Reynolds number of 450). Grashof number ranged from 9.8 × 10~6 to 3.9 × 10~7. The results showed that the buoyancy-driven secondary flow was generated right from the upstream tip of the channel heated section and was enhanced in the downstream direction. Accordingly, turbulence was generated and enhanced in the same direction. The mean streamwise velocity accelerated in the region close to the bottom heated wall in the downstream direction and the rate of acceleration increased with an increase in the bottom wall temperature. The turbulent streamwise and vertical velocities approximately reached close to the development state near the end of the channel heated section for the lowest bottom wall temperature while at the higher two bottom wall temperatures, the turbulent velocities were found to progress along the channel heated section.
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机译：实验研究了混合对流过程中低雷诺数通道流动的发展。在沿通道加热部分的五个不同位置进行了测量。实验在35、45和55（°C）的底壁温度下以0.0315 kg / s的流速（对应于未加热的雷诺数450）进行。 Grashof数范围从9.8×10〜6到3.9×10〜7。结果表明，浮力驱动的二次流恰好从通道加热段的上游尖端产生，并在下游方向增强。因此，产生了湍流并且在相同方向上增强了湍流。在下游方向上靠近底部加热壁的区域中，平均水流速度加速，并且随着底部壁温度的升高，加速度增加。对于最低的底壁温度，湍流和垂直速度在通道加热部分的末端附近接近发展状态，而在较高的两个底壁温度下，湍流速度沿着通道加热的部分发展。
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