California Polytechnic State University, San Luis Obispo is currently working towards developing a Computational Fluid Dynamics (CFD) database for future code validation efforts. Cal Poly will complete a wind tunnel test on the Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA) in the National Full-Scale Aerodynamics Complex (NFAC) 40 foot by 80 foot wind tunnel at NASA Ames Research Center in the summer of 2011. The development of two measurement techniques is discussed in this work, both with the objective of making measurements on AMELIA for CFD validation. First, the work on the application of the Fringe-Imaging Skin Friction (FISF) technique to AMELIA is discussed. The FISF technique measures the skin friction magnitude and direction by applying oil droplets on a surface, exposing them to flow, measuring their thickness, and correlating their thickness to the local skin friction. The technique has the unique ability to obtain global skin friction measurements. A two foot, nickel plated, blended wing section test article has been manufactured specifically for FISF. The model is illuminated with mercury vapor lamps and imaged with a Canon 50D with a 546 nm bandpass filter. Various tests are applied to the wing in order to further characterize uncertainties related with the FISF technique. Human repeatability has uncertainties of ±2.3% of fringe spacing and ±2.0° in skin friction vector direction, while image post processing yields ±25% variation in skin friction coefficient. A method for measuring photogrammetry uncertainty is developed. The effect of filter variation and test repeatability was found to be negligible. A validation against a Preston tube was found to have 1.8% accuracy. Second, the validation of a micro flow measurement device is investigated. Anemometers have always had limited capability in making near wall measurements, driving the design of new devices capable of measurements with increased wall proximity. Utilizing a thermocouple boundary layer rake, wall measurements within 0.0025 inches of the surface have been made. A Cross Correlation Rake (CCR) has the advantage of not requiring calibration but obtaining the same proximity and resolution as the thermocouple boundary layer rake. The flow device utilizes time of flight measurements computed via cross correlation to calculate wall velocity profiles. The CCR was designed to be applied to AMELIA to measure flow velocities above a flap in a transonic flow regime. The validation of the CCR was unsuccessful. Due to the fragile construction of the CCR, only one data point at 0.10589 inches from the surface was available for validation. The subsonic wind tunnel’s variable frequency drive generated noise which could not be filtered or shielded, requiring the use of a flow bench for validation testing. Since velocity measurements could not be made in the flow bench, a comparison of a fast and slow velocity was made. The CCR was not able to detect the difference between the two flow velocities. Currently, the CCR cannot be applied on AMELIA due to the unsuccessfully validation of the device.

Over the last 20 years, Gregory G. Zilliac of the NASA AMES Research Center has been in continuous development of a fringe-imaging skin friction PC application used in oil interferometry analysis. This application, CXWIN5G, allows users to analyze propagation of oil smears across an aerodynamic surface using photogrammetry. The purpose of this thesis is to investigate the feasibility of increasing the level of automation currently found in CXWIN5G by developing a MATLAB solver capable of determining oil smear geometry with minimal user input. There are two main automation goals of this thesis that are reflected in the core of the MATLAB solver: the determination of oil smear centerline propagation without user input and the calculation of fringe spacing without the use of fiduciary markings on the test surface. In CXWIN5G, oil smear propagation centerlines must be drawn by a user with their computer mouse. The MATLAB solver removes the necessity for this by utilizing the centroid location of each fringe as a reference for centerline propagation. The solver’s ability to calculate fringe spacing without the use of fiduciary markings is a result of its ability to accurately determine the physical dimensions captured in an image. This is done by separating the camera’s field of view into its pixel components and calculating the horizontal and vertical object length captured in each pixel. Validation of the MATLAB solver’s ability to define fringe propagation and fringe spacing is performed at multiple different camera positions. When the camera location is not directly overhead an oil smear the camera is in a state of skew. Camera skew is measured in degrees, and can occur in the horizontal or vertical direction. Images analyzed in this thesis feature representative hand-drawn oil smears, as well as oil smears created in the Cal Poly 3’ x 4’ low speed wind tunnel. The MATLAB solver’s ability to create accurate centerlines is accessed by comparing pixel coordinates of the MATLAB centerlines with pixel coordinates of centerlines created on an identical image in Microsoft Paint. During experimentation, 18 images were analyzed under both horizontal (X) and vertical (Y) skew camera conditions, with skew angles ranging from zero to 13.2 degrees. Under X-skew camera conditions the average position error between MATLAB and hand drawn centerlines is 0.6 %, while average position error under Y-skew camera conditions is 1.0 %. Fringe spacing accuracy is defined by how closely fringe spacing determined by the MATLAB solver is to fringe spacing measured by hand with a 1/16th inch ruler. Spacing analysis is performed on the same photos used in centerline determination. For X-skew camera positions, the average fringe spacing error is 6.1 %, while the average spacing error in Y-skew conditions is 4.3 %. As is discussed in later sections of this text, the X-skew fringe spacing error is artificially inflated due to human error during data collection.