In the field of yarn dyeing, the most generally employed method is a type of package dyeing which uses a package of cheese stacked on a spindle made of a perforated tube. Spindles up to now, have been designed without considering the characteristics of dyeing liquid, focusing only on the geometric configuration which cause many problems such as lack of level dyeing. To improve the level dyeing and find the appropriate spindle configuration for the most effective dyeing process, this study examines the spindle flow-field in detail, using a computational method. Flow characteristics inside the spindle have been investigated with varying in porosity, porous diameter and the velocity of the flow. The results show that the total pressure of the flow through the spindle is used to overcome body force. The characteristics of the flow from the porous spindle could also be observed. Based on the results from this study, an effective spindle configuration for level-dyeing has been proposed.
Evaporative cooling is a widely used air cooling technique. In this method, evaporation of a liquid in the surrounding air cools the air in contact with it. In the current investigation, numerical simulations are carried out to visualize the evaporation and dynamics of tiny water droplets of different diameters in a long air duct. The effect of initial droplet size on the temperature and relative humidity distribution of the air stream in the duct is investigated. Three different initial conditions of air are considered to verify the influence of ambient conditions. Droplet spray patterns are also analyzed to identify the suitable locations for the spray nozzles within the duct. The results obtained are displayed in a series of plots to provide a clear understanding of the evaporative cooling process as well as the droplet dynamics within the ducts.
A shock wave discharged from a tube leads to an impulsive noise that is similar to a sonic boom. The impulsive noise has often been a major factor in deterioration of the performance of ow devices and has hazardous effects on human beings. The objective of the current work is to develop a new technique for the control of the impulsive wave. Experiments using a simple shock tube were carried out to investigate the effect of a cavity/helical vane system on the magnitude of an impulsive wave. The results showed that the magnitude of the impulsive wave was in uenced by the detailed con guration of the helical vane inside the cavity which was installed at the exit of a tube. The results of the tests with and without the helical vane were compared to validate the effectiveness of the present control technique. The experimental data showed that the present cavity/helical vane system reduced the peak pressure of the impulsive wave up to about 50 per cent, compared with a straight tube, and was suitable for alleviating the magnitude of the impulsive wave.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.