Sharif Digital Repository

In this article a comprehensive numerical study is performed to compare the effect of fluid flow across a duct with various cross sectional shapes and with different velocities of the flow. Circular, elliptical and rectangular cross sections have been chosen for the ducts and air flows across them with four values of low Reynolds numbers in the range of Re = 1 to Re = 1000. Continuity and momentum equations with proper boundary conditions are solved in two dimensions. Streamlines, pressure distribution and Velocity profiles are obtained and creation of vortices, boundary layers, separation region, wake region, reattachment point and stagnation points are studied in detail and the results are... 

Numerical analysis has been conducted to simulate and capture Buzz phenomenon in a supersonic mixed compression air intake. Buzz is an unsteady self-sustained phenomenon occurred in supersonic intakes, especially when operating its subcritical condition, during which the system of compression and shock waves oscillate and move upstream and downstream along the intake. An axisymmetric and unsteady numerical simulation was used to solve Navier-Stokes equations in combination with URANS SST k-ω turbulence model The simulations were performed at M=2.0 and at a specific subcritical point of the intake operation where buzz was detected experimentally. Results are compared with experimental...