Uncertainty quantification (UQ) in the hypersonic flow regime offers valuable information to determine physical models in need of improvement and to assist in design of vehicles and flight experiments. Here we present results of UQ analysis based on polynomial chaos method to determine flowfield and surface heat flux uncertainty under typical blunt-body re-entry conditions. The NASA Langley cod...

Understanding and controlling the flowfield in and around a cavity has challenged researchers for a number of years. The presence of a cavity on a body has been observed to significantly increase the mean drag, cause flow-induced vibrations and give rise to strong acoustic production. Of particular interest here are the flow structure and dynamics associated with open shallow rectangular caviti...

A NUMBER of military and civilian applications require efficient operation of airfoils in low chord Reynolds numbers. The applications include propellers, sailplanes, ultralight mancarrying/man-powered aircraft, high-altitude vehicles, wind turbines, unmanned aerial vehicles, and micro air vehicles. Careful management of boundary layers on low-Reynolds-number airfoils is required to alleviate t...

We have applied formal experiment design and analysis to optimize the measurement of temperature in a supersonic combustor at NASA Langley Research Center. We used the coherent anti-Stokes Raman spectroscopy (CARS) technique to map the temperature distribution in the flowfield downstream of an 1160 K, Mach 2 freestream into which supersonic hydrogen fuel is injected at an angle of 30 degrees. C...

An application-agnostic procedure is outlined for checking the validity of momentum-deficit-based drag measurements performed under different turbulent conditions in a wind tunnel. The approach defines two-step methodology: first stage characterizes flowfield generated downstream passive grid through set statistical parameters. Acceptable values such parameters are determined by means two crite...

Title of dissertation: OBSERVABILITY-BASED SAMPLING AND ESTIMATION OF FLOWFIELDS USING MULTI-SENSOR SYSTEMS Levi D. DeVries, Doctor of Philosophy, 2014 Dissertation directed by: Professor Derek A. Paley Department of Aerospace Engineering The long-term goal of this research is to optimize estimation of an unknown flowfield using an autonomous multi-vehicle or multi-sensor system. The specific r...

The effect of an isentropic compression wave fan on shock wave/turbulent boundary layer interaction induced by a curved fin is studied the nanoparticle-based planar laser scattering method, oil flow and numerical method. consists two parts: A surface generating ensuring focuses into swept wave. flowfield compared with three-dimensional separation same deflection angle. results show that can com...

The complex spike (CS) activity of Purkinje cells in the ventral uvula and nodulus of the vestibulocerebellum was recorded from anesthetized pigeons in response to translational optic flow. Translational optic flow was produced using a "translator" projector: a mechanical device that projected a translational optic flowfield onto the walls, ceiling, and floor of the room and encompassed the ent...