Abstract:

Flow uniformity is an important index in many research fields.In order to use directly numerical simulation results to analyze flow uniformity quickly, abolish the data collection points setting and simplify computation process, a new correlation based on area-weighted and mass-weighted average velocity was proposed through the uniformity analysis of 24 velocity distribution under the circumstance of three velocity change at assumed cross-section in this study.The correlation and the corresponding formula in the literature were respectively adopted to calculate the uniformity of 24 velocity distribution at assumed cross-section.The results showed that the evaluating results by the correlation were basically consistent with that by the formula when velocity distribution uniformity was over 60%, the evaluating results by the correlation were worse than that by the formula when velocity distribution uniformity was less than 60%.However, the flow that uniformity is worse always need to further improve its structure, the uniformity was just providing a basis for improvement.Therefore, the results by the correlation have fully reference value for analysing flow uniformity.Finally, take supplying air of a metro vehicle air-conditioning duct as an example, the above theoretical analysis results were further verified, which confirmed the rationality of the correlation reflecting flow uniformity.

摘要：

流动均匀性是很多领域中重要的衡量指标，为便于直接采用模拟结果进行均匀性分析，取消数据采集点的设置，简化计算过程，通过对假定截面上3种速度变化时24种速度分布均匀性的分析，提出了基于面积加权平均速度和质量加权平均速度的均匀性计算关联式，并采用关联式和文献中相应公式分别对该截面上24种速度分布的均匀性进行计算，结果显示：当均匀性大于60%时，关联式和公式的结果基本吻合,当均匀性小于60%时，关联式的结果低于公式的结果，但由于均匀性较差的流动需要继续改善其结构，均匀度只是提供了需要改善的依据，所以关联式的结果完全有参考价值。最后以某地铁车辆风道送风为例对理论分析结果进行验证，确认了关联式反映流动均匀性的合理性。