دانلود رایگان مقاله مطالعه ویژگی جریان هوای حالت تهویه ستون مربعی شکل

Abstract

A new air distribution pattern, the square column attached ventilation mode, which can be applied to ventilation and air-conditioning systems in large space buildings, is presented in this work. An experimental method was employed to visualize and investigate the airflow characteristics of this novel ventilation mode under isothermal conditions. Our results show the behavior of square column attached ventilation in the form of maximum jet velocity decay, non-dimensional velocity profiles and jet spreading rate at different supply air velocities. The empirical equations governing these characteristic parameters were derived and compared with other types of air jets. The results show that the square column attached ventilation mode is a particular air distribution pattern which combines the advantages of mixing and displacement ventilation. When using the slot outlet with an aspect ratio of 20, the air flow can be treated as a conventional plane wall jet, however the velocity decay and jet diffusion in the occupied zone can be much faster. The obtained results can be helpful in understanding a new air distributiondsquare column attached ventilation used for ventilation and air-conditioning systems design

5. Conclusions

The airflow characteristics of square column attached ventilation (SCAV) were investigated experimentally under isothermal conditions. The results show that the flow field of the SCAV mode can be classified into three regions: the column attached region, the primary floor attached region and the confluent floor attached region. The empirical equations for the decay of maximum velocity, the non-dimensional velocity profiles and the rate of jet spread in these regions were obtained and compared with empirical solutions for similar jets taken from the literature. Based on the experimental results and on such comparisons, the following conclusions can be drawn: