| บทคัดย่อ(English) |
The phenomena of air flow past the parallelinclined flat plates in a square duct is studiedthrough the numerical solution by using computationalfluid dynamics ( CFD ) technique. A computer programcalled PHOENICS, is adopted to solve forthree-dimensional steady turbulent flow under thefinite volume method. The governing equations areincompressible ensemble-averaged Navier-Stokesequations. The Reynolds stresses are modeled by the k -(...) turbulence model with Boussinesq's eddy viscosityassumption. To verify the numerical accuracy and validity ofthe turbulence model, the results are first comparedwith experimental velocity data. Comparisons betweenmeasured and calculated results are in generalsatisfactory, although some discrepancies are found.Finally, the effects of the number of flat plates, theinclination of flat plates and high Reynolds number inthe duct flow, to the distance for fully developedflow, as well as total pressure drop, are investigated. The predictions show that the development lengthextends when the number of flat plates decreases,however, such length is shortened when the inclinationof flat plates becomes smaller. In case of Reynoldsnumber within the range of study, the numerical resultspredict that the air flow at higher Reynolds numberrequires the development length to be longer than thelower Reynolds number condition. Furthermore, it isfound that the single blade damper causes totalpressure drop to be significantly higher than themulti-blade damper. |
