M.Sc. Tezi Görüntüleme | |||||||||||||||||||||
|
|
||||||||||||||||||||
| Summary: In this study, the flow fields of unconfined and confined multiple slot jets impinging flat plates have been investigated experimentally and numerically. Pressure and temperature distributions at the flow fields were obtained for various Reynolds numbers and nozzle-to-plate spacings. The effects of jet confinement, Reynolds number, nozzle-to-plate spacing on the flow structure and heat transfer were investigated. While the surface pressure distributions on both impingement and confinement plates are independent from the Reynolds number, they have been largely affected from nozzle-to-plate spacings. Jet confinement causes considerable difference especially for the small nozzle-to-plate spacings. While subatmospheric regions are not observed in the unconfined jets, subatmospheric pressure regions occur on the both confinement and impingement plates in the case of confined jet. These regions which are more effective at the decreasing nozzle-to-plate spacings show that there are reversed flows on the both confinement and impingement plates.In the numerical simulation, solution accuracy of Realizable k- turbulence model is not enough for the small nozzle-to-plate spacing (H/D<2) because of flow deflection. For this reason, there is a discrepancy between experimental and numerical results. But for the large nozzle-to-plate spacings (H/D≥2), turbulence model has good performance at the prediction of flow characteristics and there is a good accordance between experimental and numerical values. Key Words: Reynolds number, nozzle to plate spacing, pressure coefficient, heat transfer rate, experimental and numerical study | |||||||||||||||||||||