الفهرس | Only 14 pages are availabe for public view |
Abstract The purpose of this work iS to provide the correlation between the greenhouse, the flow separation, and now separation control. in particular in internal flow. Understanding of some basic mechanism of greenhouse effects has increased substantially in the iast few years. This undetstauding suggests that taming of greenhouse - the new challenge in the field of flow separation control ~ is possible so as to eliminate some of ib deleterious effecl<; while enhancing its useful traits. Under certain conditions of pressure and velocity gradients, wall-hounded flows separate. To improve the performance of natural or man-made flow systems, it moy beneficial to de)a.y or advance this detachment process. A well designed and manufactured of two-dimensional flat-walled diffuser is manipulated. The diffuser with specific dimensions has a separation and backflow near the exit due to an adverse pressure gradient. The experimental measurements were carried out at four stations to gain information of pressure and velocity distributions of air flow through the diffuser. The experimental procedure begins with normal air in order to be used as a reference with the hot air with free exit and hot air with boundary condition at the exit of the diffuser, greenhouse simulation. The separation point is determined theoreticaUy using an integral approach of empirical method. Flow separation control is currently employed, injection of air directly in the boundary-layer regions, to show the effect of blowing on flow separation and the performance of the diffuser. However, the pressure recovery coefficient and the performance of the diffuser are found to be function of the rate of injection. The hot air with different temperatures through the diffuser is used to investigate the effect of hot air on flow separation. However, the new location of separation point is. expected due to the e!Tect of hot air and compared with the ca..”ie of using normal air. The greenhouse effect is attained in lhe experiment through using a. cotton screen with specific porosity located near the exit of the diffuser. The cotton screen as an impedance creates a pressure DROP across it that associates an adverse pressure gradient in the boundary layer regions near the exit of the diffuser. However, the location of the separation poinl and the pressure recovery coefficient would be expected to be related with the greenhouse effect. Therefore, the experimental measurements are necessary and relevant to investigate the link between the greenhouse, the flow separalion, and the flow separation controL |