Unsteady double diffusive convection under the influence of time-periodic sidewall temperature inside a rectangular enclosure with a porous wall is performed using numerical simulation and analytical prediction. The ranges of investigated physical parameters are listed as Darcy number (10⁻¹⁰ ≤ Da ≤ 10¹), thickness of porous wall (0 ≤ d ≤ 1), thermal Rayleigh number (10³ ≤ Ra ≤ 10⁷), buoyancy ratio (−1 ≤ N ≤ 1) and oscillating frequency of time-periodic sidewall temperature (0.01 ≤ ω ≤ 10). Results indicate that rates of heat and moisture transfer are impacted by time-periodic temperature and have a sinusoidal variation with time. The heat and moisture resonance phenomenon occurs when the convection effect is sufficiently stronger. Scale analysis has been performed to obtain the correlations of overall heat and moisture transfer rates in basic steady state and the resonant frequency, where the fluctuations of heat and moisture transfer are increased. A good agreement is observed from the analytical and numerical results. Present work could be applied to determine the heat and moisture transfer rates and resonant frequency in a thermal storage system, where the sidewall temperature is varying periodically with time due to the weather condition (solar radiation) and ambient temperature during a typical day.

利用数值模拟和分析预测方法，在具有多孔壁的矩形壳体内，在时间周期内侧壁温度的影响下，进行了非稳态双扩散对流。调查物理参数的范围被列为达西数（10 ^-10  ≤ 沓 ≤10 ¹），多孔壁的厚度（0≤  d  ≤1），热瑞利数（10 ³  ≤ 太阳神 ≤10 ⁷），浮力比（ -1≤  ñ ≤1）和时间周期侧壁温度的振荡频率（0.01≤ω≤10）。结果表明，热量和水分的传递速率受时间周期温度的影响，并随时间呈正弦变化。当对流效果足够强时，会发生热湿共振现象。已经进行了尺度分析以获得基本稳态下的总的热量和水分传递速率与谐振频率之间的相关性，其中热量和水分传递的波动增加了。从分析和数值结果可以观察到很好的一致性。当前的工作可以应用于确定蓄热系统中的热量和水分传递速率以及共振频率，