凹坑局部干扰热环境数值模拟研究

通过求解雷诺平均N-S方程,采用NND格式和SST两方程湍流模型,对开/闭式凹坑二维和三维流动情况进行了模拟,得到了凹坑局部压力和热流的分布,并与试验结果进行了比较。计算结果表明,凹坑局部峰值压力和热流均出现在后沿附近,且闭式凹坑局部热流较开式凹坑更为严重;在三维流动情况下,由于侧壁的影响,开式凹坑峰值热流沿后沿展向变化较小,而闭式凹坑峰值热流会离开后沿中心而出现在后沿靠近侧壁的区域。

基于毛细管网的相变蓄热模块实验研究

目的为提高冬季农村居民的室内舒适度,改善农居室内局部热环境,降低能耗,减少污染,提出一种新的将相变材料和毛细管网型末端相结合的相变蓄热模块供暖系统.方法根据供水温度和相变材料的填充量的不同组合设计了不同工况,并搭建了对比测试实验平台,对模块蓄放热时间及模块表面温度进行测试和分析.结果相变蓄热模块系统在填充4 kg相变材料、供水温度为50℃时蓄热时间最短,为80 min;在填充5 kg相变材料、供水温度为40℃时的蓄热时间最长,为160 min;在填充5 kg相变材料,供水温度为50℃时的蓄热时间为100 min;在填充4 kg相变材料,供水温度为40℃时的蓄热时间为120 min;填充4 kg和5 kg相变材料的模块系统表面温度保持在25℃以上的持续放热时间分别为8 h和10 h.结论相变蓄热模块供暖系统可联合火炕以及太阳能热水系统、户用小型锅炉等多种低温热源;基于毛细管网的相变蓄热模块能较好的满足用户对模块放热时间的要求,可以有效改善室内局部热环境.

浅谈树木在环境中的作用和生长发育障碍

绿色植物不仅能给我们带来美好的景观效果,它们还会对周围的空气性质产生很大影响。建筑设计中有目的引用绿色植物,不但对室内空调的负荷增减有影响,还直接影响着换气时进入室内的外界空气的形状以及开窗时的凉爽感。如何很好的使用绿色植物,以及使用中避开人为的生长发育障碍,提其生长发育的条件。笔者就以上几点谈谈体会。

Effect of local thermal sensation on whole-body thermal sensation under stable non-uniform environment

To reveal the principles of human thermal responses and find out the effects of body parts on whole-body thermal sensation,through a subjective survey,experimental investigations on human responses are carried out when a single body part is thermally stimulated.Cooling airflow is sent to seven body parts,respectively.Totally 94 samples are tested.To eliminate the obvious multicollinearity of thermal sensation among different body parts,the principal component regression approach is adopted to obtain the principal components for the body parts under different experimental conditions.Through regression and analysis of principal components,the weighting factors of the seven body parts are obtained.A predictive model on whole-body thermal sensation is obtained based on the weighting factors.The results show that the different characteristics of trunk and limbs are clearly seen.The weighting factors of local thermal sensation are integrated values,and there is little difference among values of different body parts.