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Full-Text Articles in Aerospace Engineering
Hypersonic Boundary-Layer Stability Across A Compression Corner, Hongwu Zhao
Hypersonic Boundary-Layer Stability Across A Compression Corner, Hongwu Zhao
Mechanical & Aerospace Engineering Theses & Dissertations
Stability of a hypersonic boundary-layer over a compression corner was investigated numerically. The three-dimensional compressible Navier-Stokes equations were solved using a fifth-order weighted essentially non-oscillating (ArENO) shock capturing scheme to study the shock wave and boundary-layer interactions. The boundary-layer stability was studied in three distinct regions: upstream of the separation region, inside the separation region and downstream of the separation region. After the mean flow field was computed, linear stability theory was employed to predict the unstable disturbance modes in different flow regions and also to find the most amplified disturbance frequency across the compression corner. Gortler instability computations were …
Boundary Layer Influences On The Subsonic Near-Wake Of A Family Of Three-Dimensional Bluff Bodies, Charles Willliam Alcorn
Boundary Layer Influences On The Subsonic Near-Wake Of A Family Of Three-Dimensional Bluff Bodies, Charles Willliam Alcorn
Mechanical & Aerospace Engineering Theses & Dissertations
A study is reported on subsonic bluff body near-wake flows. It has been determined that one family of bluff bodies, namely slanted-base ogive cylinders, can experience either a closed recirculating near-wake, or a longitudinal vortex near-wake depending on the base slant-angle and the Reynolds number. This suggests a dependence of near-wake parameters on the state of the boundary layer ahead of separation. This report addresses the influence of the boundary layer on the near-wake of slanted-base bluff bodies. Experiments were conducted in two facilities, the 6-inch Magnetic Suspension and Balance System (MSBS) at NASA Langley Research Center and the Old …
An Experimental Study Of An Axisymmetric Turbulent Boundary Layer Disturbed By A Periodic Freestream, Chithrabhanu Koodalattupuram
An Experimental Study Of An Axisymmetric Turbulent Boundary Layer Disturbed By A Periodic Freestream, Chithrabhanu Koodalattupuram
Mechanical & Aerospace Engineering Theses & Dissertations
Behavior of an axisymmetric equilibrium turbulent boundary layer disturbed by a propeller wake in the freestream was investigated experimentally. Tests were conducted in a low speed wind tunnel and measurements of turbulence quantities were made using an X wire probe and a constant temperature anemometer. The boundary layer flow on a cylindrical body was characterized by measuring its gross parameters and comparing them with classical values. Propeller speed was measured using an electronic circuit whose output signal was also used to trigger hot wire probe. Gross boundary later characteristics of the disturbed boundary layer did not deviate appreciably from the …