Boundary layer studies on rough flat plates under negative pressure gradient

摘要

There has been substantial research on boundary layer development on different objects. In this research project velocity distribution and boundary layer generation helps us to design the objects according to the steam lined bodies. Rough flat plate had been used as object in the experiment. It will help the objects to move easily in fluids. For the basic understanding of flow characteristics over a rough flat plate, the experiment was carried out in the laboratory using a low speed wind tunnel. Velocity reading are observed at specified locations over the rough flat plate (wood surface with stacked on different grade emery papers) with a free stream velocity. With the concept of 0.99U (free stream velocity) velocity profile is plotted at location of working sections length in the longitudinal direction .The boundary layer thickness ranges from 1.2mm to 59.2mm is generated for the model of 100cm length. To produce negative pressure in experiment, the flat plate is being inclined. The boundary layer growth gives a brief idea of fluid flow over a flat surface. Comparative study is done between four rough flat plates for better understanding of boundary layer theory. Tabular results of local velocity at every section had discussed here for the laminar to turbulent flow.