This study evaluates a data assimilation framework based on reduced-order modeling (ROM-DA), complemented by a hybrid data-filling strategy, to reconstruct dynamic temperature fields in a phase-change-material (PCM) integrated solar chimney from limited temperature measurements. The goal is to enhance the estimation accuracy of the outlet airflow velocity. A regularized least-squares formulation is employed to estimate temperature distributions within an inclined solar chimney using RT-42 as the PCM. The methodology combines (i) a reduced-order model derived from high-fidelity finite-volume simulations of unsteady conjugate heat transfer with liquid-solid phase change and surface radiation, and (ii) three experimental datasets with 22, 135, and 203 measurement points. Missing data are reconstructed using a hybrid filling scheme based on boundary-layer and bicubic interpolations. The assimilated temperature fields are integrated into the thermally coupled forward solver to improve velocity predictions. Results show that the ROM-DA framework reconstructs the transient temperature fields in both the air and PCM domains with relative errors below 10 percent for sparse data and below 3 percent for expanded datasets. When applied to experimental measurements, the approach enhances the fidelity of temperature and velocity fields compared with the baseline model, reducing the outlet velocity RMS error by 20 percent. This represents the first application of a ROM-DA framework to a coupled multiphysics solar chimney with PCM integration, demonstrating its potential for near-real-time thermal state estimation and digital-twin development.

翻译：本研究评估了一种基于降阶建模的数据同化框架，辅以混合数据填充策略，用于从有限温度测量数据中重建相变材料集成太阳能烟囱的动态温度场。其目标是提高出口气流速度的估计精度。采用正则化最小二乘公式，以RT-42作为相变材料，估算倾斜太阳能烟囱内的温度分布。该方法结合了：(i) 基于非稳态共轭传热（包含液固相变和表面辐射）的高保真有限体积模拟导出的降阶模型，以及(ii) 包含22、135和203个测量点的三组实验数据集。缺失数据通过基于边界层和双三次插值的混合填充方案进行重建。同化后的温度场被集成到热耦合正向求解器中，以改进速度预测。结果表明，对于稀疏数据，ROM-DA框架重建空气域和PCM域瞬态温度场的相对误差低于10%；对于扩展数据集，相对误差低于3%。当应用于实验测量时，与基准模型相比，该方法提高了温度和速度场的保真度，将出口速度的均方根误差降低了20%。这是ROM-DA框架首次应用于相变材料集成的耦合多物理场太阳能烟囱，展示了其在近实时热状态估计和数字孪生开发方面的潜力。