振动对带肋通道内流动与传热影响的数值模拟

Numerical Study on Flow and Heat Transfer in a Vibrating Channel with Rib Turbulators

运用Fluent UDF动网格技术将二维流场中振动对带肋矩形直通道的流动与换热特性进行了数值模拟,分析了相同振动条件下入口速度对流动与换热的影响,以及相同振动强度下振幅和频率对流动与换热的影响.结果表明:相同振动条件下,Re越大,换热增长率越低,入口静压波动越大,且静压峰值相位相对于振动峰值相位逐渐超前;相同振动强度下,振幅越大,振动引起的换热波动越小,换热增长率越低;当振幅大于一个临界值时,振幅对换热的影响不明显;振幅越大,入口静压波动幅度越大;振动可以强化换热,但是随着Re和振幅的增大,局部区域会出现抑制换热的情况.

The two-dimensional flow field and heat transfer characteristics of a rectangular vibrating chan- nel with rib turbulators were numerically investigated using the dynamic meshing and UDF programming technology via CFD Fluent software, so as to analyze the effects of inlet velocity, vibration amplitude and vibration frequency on the flow field and heat transfer characteristics under same vibration conditions. Re sults show that under same vibration conditions, and with the rise of Re, the enhancement of heat transfer weakens, the fluctuation of inlet pressure increases, and the phase of pressure peak advances compared with the stationary case. At same vibration intensities, the higher the vibration amplitude is, the poorer the enhancement of heat transfer will be, resulting in reduced growth rate of heat transfer~ however, when the amplitude gets up to the critical value, the effect of vibration amplitude would affect little on the heat transfer; the fluctuation of inlet pressure intensifies with the rise of vibration amplitude. Generally, the vi- bration enhances the heat transfer, but in some regions, it may also inhibit the heat transfer as the Re and vibration amplitude increase.