![]() ![]() For quantitative measurements the recorded temperatures must be corrected for radiation heat exchange with the environment, a complicated task since knowledge about the local heat transfer coefficients, view factors and surrounding surfaces are needed to be known with good accuracy.Ĭomputed tomography together with optical sensing is a promising tool in order to study the dispersion of airborne pollutants in buildings. It is applicable to both laboratory and field test environments, such as in industries and workplaces. Infrared thermography is an excellent technique for visualization of air temperature and airflow pattern, particular in areas with high temperature gradient, such as close to diffusers. Computational Fluid Dynamics (CFD) has been used to predict the velocity and temperature distributions and to improve the current limitations. These methods are explored with respect to applicability and reliability. ![]() ![]() The main aim of this research is to improve the knowledge of the whole-field techniques used to measure and visualize air temperatures and pollutant concentrations. Complaints about drafts are often associated with this type of ventilation system. In particular, the near-zone of supply air diffusers in displacement ventilation is very critical. One of the reasons why so many problems are associated with indoor climate is that it is more or less invisible it is hard to understand something that cannot be seen. The indoor climate not only heavily affects people’s health and life quality, but also their productivity and ability to work efficiently. The thermal indoor climate is a complicated combination of a number of physical variables, all of which strongly affect people’s well-being. Radiant exchange between the exterior window and interior surfaces causes a significant change in the window temperature. The results indicate that, for the same supply air flow, operating only a single diffuser initiates more mixing of the room air flow, which results in enhanced temperature uniformity compared to that for two diffusers. For a certain discharge angle in the heating case, the air flows along the ceiling. The results show that the offset and lips of the diffuser work together to determine the discharge air angles, which play an important role in determining the room air flow patterns. Simulations are conducted for heating and cooling of the room with one or two supply air diffusers. The room air flow model is assessed using several previously documented problems with various geometries and boundary conditions. As an input to the full-scale 3-D room model, a 2-D diffuser model that supplies direction and magnitude of air flow into the room is developed and evaluated using infrared visualization. A computational fluid dynamics model with radiant exchange between surfaces is developed to examine the air flow characteristics of a room with square cone diffusers. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
February 2023
Categories |