A real-time energy management display is developed and evaluated, and the feasibility and utility of the display in providing real-time guidance and information on the aircraft’s energy state was investigated. Flight simulations were conducted with the UTSI Aviation Systems research flight simulator to validate the display and evaluate its utility for flying along constant specific excess power contours, and directly obtaining specific excess power contours from level acceleration flight test. The display was evaluated for flying optimal paths. This study considered the energy state of the aircraft from the point of view of the relation that exists between specific excess power and the forces in flight. The approach yields as one result a cubic function for the specific excess power, Ps, of the aircraft. We then directly solve for velocity, V as the control parameter for a given Ps, as a function of altitude, H. This technique is then used to build a real-time energy management display that provides guidance and real-time information of the aircraft’s energy state. Flight simulation results proved the display to be successful in obtaining direct Ps contours from level acceleration flight tests and in providing guidance for flights along constant Ps contours at low airspeeds although it was difficult to keep the Ps constant. However flights along zero Ps contours and along constant Ps contours at very high speeds were not successful. The application of the display in flying optimal paths was also not very successful with the current structure of the display. This was due to the fact that the display’s guidance information is provided in a digital format which is very sensitive, and tracking a number for guidance is nearly impossible.

Flame stabilization behavior is experimentally investigated at engine relevant conditions using an optical sensor imaging system. Optical imaging systems can provide insight into local engine behavior as opposed to measurements with devices such as flowmeters. Two facilities are utilized to examine premixed flame combustion stabilized by bluff body flame holders at both atmospheric and elevated pressures. C2* and CH* chemiluminescence signals are recorded on a four-band imaging system to calibrate the sensor intensity ratio of C2*/CH* to the flame equivalence ratio. Tracking this ratio across flame position can provide local information concerning flow disturbances and other combustor instabilities. Several fuels (methane, propane, and liquid Jet-A) are tested to examine the change in chemiluminescence ratios that can be found in industrial applications. The calibrations are obtained across a wide range of equivalence ratios (0.6-1.4) and for pressures of 1 and 5 bar. Methane flames showed very low C2* signal value in lean and stoichiometric flames, resulting in non-monotonically increasing calibration curves. Propane flames had a monotonic calibration curve, attributed to greater C2* signal intensity. The Jet-A-air flames also had non-monotonically increasing calibrations at 1 bar, but a monotonic curve at elevated pressure. These calibrations are then applied to the average C2*/CH* intensity ratio images to yield maps of flame equivalence ratio. Downstream variation in the equivalence ratio of the unconfined facility is attributed to air entrainment, while in the weaker signal is thought to be a function of the local flame properties.

Remotely operated aerial vehicles such as quadcopters and drones have been, and continue to be, used extensively by military personnel, industry, and civilians alike. Current research into unsteady flapping mechanisms has been primarily concerned with the heaving and pitching motion of rigid foils. The purpose of this thesis is to investigate how a dynamically morphing foil affects the fluid-structure interactions of unsteady flapping locomotion as measured by lift, drag, and vorticity. The effects of non-dimensional heaving amplitude and reduced frequency are studied using force sensor and Particle Image Velocimetry (PIV) measurements. Two reduced frequencies are tested: one in the unsteady range, κ=0.105, and one in the highly unsteady range, κ=0.209. Two morphing modes were investigated: spanwise twisting in the direction of upward pitch (Mode A), and spanwise twisting in the direction of downward pitch (Mode B). The effects of changing reduced frequency and nondimensional heaving amplitude were explored for each morphing mode. Force sensor measurements showed that Mode A recovered some of the lift that is usually lost during the upstroke of flapping locomotion. Additionally, Mode A maintained a near-constant lift coefficient during the transition between downstroke and upstroke, suggesting a more stable form of locomotion. PIV results showed that Mode A limits circulation and leading-edge vortex (LEV) growth during the downstroke, keeping Cd ≈ 0 at the cost of reduced lift. By contrast, PIV results showed that Mode B increases the circulation during the downstroke, resulting in large increases in both lift and drag coefficients. Force sensor data showed that this effect on lift is reversed during the upstroke, where Mode B causes negative lift. The effects of each morphing mode is caused by changes in shear layer velocity that occur as a result of spanwise twisting. The twisting performed by Mode A reduces the effective angle of attack, resulting in a reduced shear layer velocity and lower circulation. The twisting performed by Mode B does the exact opposite, increasing the effective angle of attack and consequently increasing the shear layer velocity and circulation.

Corrosion presents an inherent challenge in the safe and effective use of metallic aerospace structures for extended periods of time. Progress in the fundamental understanding of corrosion initiation and propagation under stress requires a multi-scale approach that leverages experiments to develop predictive models. Although there exists a large amount of research results tracking the corrosive processes of anodic dissolution and hydrogen embrittlement, the amount of available data and modeling of the micro-scale initiation of corrosion is sparse. This work leverages a suite of characterization techniques to systematically analyze an aerospace grade aluminum alloy AA7075-T6, providing important multi-scale data for correlation with overall corrosion progression. Samples were exposed to 3.5% NaCl solution at various exposure times under loading with a micro-tensile system. Optical microscopy, Raman spectroscopy and Energy Dispersive X-ray Analysis provided spatial maps of the visual and chemical alloy signatures before, during, and after failure, to analyze and track the progression of corrosion. An experimental setup for in-situ Digital Image Correlation (DIC) was developed to provide strain maps to study local concentrations around corrosion pits and quantify the impact on the material tensile performance. The material morphology and composition from these measurements identified localized oxide formations at a high spatial resolution that can be used to quantify the corrosion rates. Meanwhile, in-situ DIC measurements provided results showing stress concentrations formed by the corrosion pits and the reduced mechanical performance with exposure. The results demonstrate that multiple factors affect corrosion susceptibility and material deterioration, and highlight the need to overcome experimental challenges in quantifying these factors distinctly. This work demonstrates the capacity for highly detailed analysis of corrosion initiation and propagation in affected alloys using the processes outlined in the systematic study. The outcomes provide a pathway to address methods for maintaining the integrity of these alloys and extending their lifespan.

The chemistry of propane continues to play a pivotal role in today's power production technologies. As reliance on natural gas expands as greener cleaner fuels are sought throughout the world, especially as countries are attempting to transition away from traditional coal and crude-oil fired plants towards solar, wind, and hydro-electric sources. Natural gas, often seen as a bridge fuel between these two competing ends, has been in the recent past and for the foreseeable future will continue to play an important role in the energy sector. Among the components of natural gas, propane plays a key role in the chemistry for both pyrolysis and combustion. While the composition of natural gas is primarily dominated by the presence of methane, the heavier hydrocarbons especially propane dominates the chemistry of reactions. Thus, developing a healthy understanding of the pyrolysis of propane will aid in deepening insights into the chemistry that dominates that of natural gas. The pyrolysis of propane was carried out behind reflected shockwaves at elevated temperatures. Species concentration histories were recorded simultaneously using a broadband mid-infrared optical parametric oscillator to probe the reacting flows. Concentration histories for methane, acetylene, ethylene, ethane, propene, and propane were collected over a range of pressures and temperatures (pressures of ~4 to 5 atm, and temperatures of 1105 to 1304 K). These species were chosen due to there prevalence in the computational and theoretical framework of the pyrolysis of propane, but have been difficult to experimentally measure due to overlapping molecular absorption spectra.

This thesis involves the experimental wind tunnel testing of a 0.127m by 0.127m square-base bluff body to test the effectiveness of trailing edge tabulations to reduce drag in the Cal Poly 0.912m by 1.219 m low-speed wind tunnel. To accomplish this, the boundary layer was first measured on the trailing edge of the model for the three speeds at 10, 20, and 30 m/s, with Re = 8.3e4, 1.6e5 and 2.5e5 respectively, without the tabs. Three different tests were performed to determine the effectiveness of the tabs. These tests included base pressure measurements, total drag force measurements and hotwire velocity fluctuation measurements. These tests were repeated with tabs on the model’s trailing edge at the three different tab heights and without tabs at all three test speeds. The base pressure measurements showed a decrease in average base pressure with the addition of tabs which signifies an increase in drag. The total drag measurements confirmed this by showing that the overall force increases with the addition of the tabs. The hotwire tests further confirm this by showing that the vortex is present for every configuration tested. This thesis showed that the addition of tabs was unsuccessful in reducing the effects of the vortex shedding for a square-base bluff body. The addition of low, medium, and high tabs to the square base of the bluff body all showed an increase in vortex strength and overall drag. Further study is required to determine if drag savings are feasible for tabs all around the square base of the bluff body and at different locations.

A flight test program that evaluated the results of a CP140 Aurora cockpit modernization project was conducted between May 2004 and October 2005. This paper uses the results of that test program to show how basic human factors principles were violated which led to the identification of multiple design deficiencies. This paper proposes that the failure to apply good human factors principles when designing aircraft displays can lead to unacceptable deficiencies. The result can be poor modal awareness, confusion in the cockpit, and often negative training for the pilots. In particular, four major deficiencies were analyzed to determine the specific human factors principles that were breached. The violations included a lack of concise and relevant feedback to the pilot, unclear and ambiguous annunciations, poor use of colour coding principles and logic, a lack of suitable attention capture cueing, inappropriate alert cueing, an absence of aural cueing during specific degraded modes of operation, excessive cognitive workload, and a failure to incorporate the pilot as the focal point of the display design, also known as a human centred design philosophy. Recommendations for system design enhancements are provided to ensure safe and effective operations of this prototype system prior to operational implementation. The evaluation of the prototype system design was conducted by a flight test team from the Aerospace Engineering Test Establishment in Cold Lake, Alberta and supported by the Maritime Proving and Evaluation Unit in Greenwood, Nova Scotia. The test program encompassed a thorough review of system design documentation, abinitio training and preliminary testing in a Systems Integration Lab and 40 flight test missions. The recorded deficiencies were based upon the observations of two Qualified Test Pilots.

The use of Unmanned Aerial Vehicles (UAVs) are rapidly expanding and taking on new roles in the military. In the area of training and targeting vehicles, control systems are expanding the functionality of UAVs beyond their initially designed purpose. Aeromech Engineering’s NXT UAV is a high speed target drone that is intended to simulate a small aircraft threat. However, in the interest of increasing functionality, enabling NXT to accomplish wings level skidding turns provides the basis for a UAV that can simulate a threat from a missile. Research was conducted to investigate the aerodynamic and performance characteristics of a winged vehicle performing high acceleration skidding turns. Initially, a linear model was developed using small disturbance theory. The model was further improved by developing a six degree of freedom simulation. A controller using four loop closures and utilizing both rudder and aileron for control was developed. Any outside guidance system that navigates using a heading command can easily be integrated into this controller design. Simulations show this controller enables the NXT UAV to accomplish up to 3 G wings level skidding turns. Further testing, showed that the controller was able to tolerate significant turbulence, sensor noise, loop failures and changes within the plant dynamics. This research shows how it is possible for a winged UAV to easily maneuver using wings level skid turns.

Aluminum alloys are used on aerospace vehicles due to their high strength-to-weight ratio, formability and machinability. However, they become vulnerable to stress corrosion cracking (SCC) during their service life. SCC is primarily caused by the material's stress condition, a suitable corrosive environment and material susceptibility. It is also influenced by a mixture of electrochemical, mechanical, and chemical factors. Due to the complexity of SCC, tools with better resolution and sensitivity are needed to better understand the impact and interaction of the contributing factors. A vast amount of research has been done to study SCC behavior, but the scale of characterization must be reduced to elucidate the key initiation mechanisms. In this work, it is shown that SCC initiation was detected early via micro-digital image correlation (micro-DIC) prior to the crack being discernible in microscopy images. The initial effort to monitor stress corrosion cracking in AA7075-T6 involved using a pixel resolution of 3.825 microns/pixel, frame rate of 10-15 min/image and an airbrush nozzle diameter of 0.3 mm for the speckle pattern, which led to the detection of crack initiation at 98% failure load. By using a pixel resolution that is 6 times smaller, a frame rate of up to 60 times less time per image, and an airbrush nozzle that is 2 times smaller, the first observation of strain concentration marking the eventual failure region of the AA7075-T6 sample was detected as early as 58% failure load. When the micro-DIC technique was applied to study SCC behavior in additively manufactured AlSi10Mg, the first observation of localized strain marking the eventual failure region of the sample was detected at 78% failure load. X-ray synchrotron tomography was used to qualitatively assess the hydrogen bubble and precipitate formation and to quantitatively assess the post initiation crack growth in AA7075-T651. With improved micro-DIC parameters and correlation with experimental outcomes from x-ray synchrotron tomography, multiple factors contributing to SCC can be assessed to better understand the mechanisms of SCC initiation. Correlations of material exposure time and load with SCC initiation can provide data for developing corrosion control strategies and new and improved alloys or heat treatment, as well as understanding SCC behavior in alloys made through unconventional means, such as additive manufacturing. The impact of this work lies in the life extension of alloys and greater reusability and fatigue life extension of aerospace vehicles.

Results from Cal Poly's recent wind tunnel test, during the Winter of 2011-2012, in the 40- by 80-foot test section at the National Full-Scale Aerodynamics Complex (NFAC) at NASA Ames Research Center are presented. AMELIA, the Advanced Model for Extreme Lift and Improved Aeroacoustics, is the first full-span, cruise efficient, short take-off and landing (CESTOL) model incorporating leading- and trailing-edge blowing wing circulation control and over-the-wing mounted turbine propulsion simulators (TPS) to date. Testing of the 10 foot span model proved successful and was the result of a 5 year NASA Fundamental Aeronautics Program Research Announcement. The test generated extensive low-speed experimental aerodynamic and acoustic measurements. All of the results associated with Cal Poly's effort will be available in an open-source validation database with the goal of advancing the state-of-the-art in prediction capabilities for modeling aircraft with next generation technologies, focusing on NASA's N+2 generation goals. The model's modular design allowed for testing of 4 major configurations. Results from all configurations are presented. Out of a total of 292 data runs, 14 repeat run configurations were obtained. Overall repeatability of test data are good. Factors contributing to non-repeatability in the test data were assessed and showed high pressure air line temperature to be a primary factor. Test data shows drastic improvements in performance are obtained when incorporating leading edge blowing: wing stall can be delayed to more than 25 degrees angle-of-attack at lift coefficients exceeding six. Without the introduction of leading edge blowing to increase boundary layer momentum and maintain flow attachment around the leading edge, STOL performance suffers. Similar runs for isolated trailing edge blowing show a reduction in maximum lift coefficient to three with stall occurring at zero angle-of-attack. Testing at two engine pylon heights allowed for the highly coupled propulsion and flow control system to be characterized.