A multi-fidelity framework for physics based rotor blade simulation and optimization

New helicopter rotor designs are desired that offer increased efficiency, reduced vibration, and reduced noise. This problem is multidisciplinary, requiring knowledge of structural dynamics, aerodynamics, and aeroacoustics. Rotor optimization requires achieving multiple, often conflicting objectives. There is no longer a single optimum but rather an optimal trade-off space, the Pareto Frontier. Rotor Designers in industry need methods that allow the most accurate simulation tools available to search for Pareto designs. Computer simulation and optimization of rotors have been advanced by the development of "comprehensive" rotorcraft analysis tools. These tools perform aeroelastic analysis using Computational Structural Dynamics (CSD). Though useful in optimization, these tools lack built-in high fidelity aerodynamic models. The most accurate rotor simulations utilize Computational Fluid Dynamics (CFD) coupled to the CSD of a comprehensive code, but are generally considered too time consuming where numerous simulations are required like rotor optimization. An approach is needed where high fidelity CFD/CSD simulation can be routinely used in design optimization. This thesis documents the development of physics based rotor simulation frameworks. A low fidelity model uses a comprehensive code with simplified aerodynamics. A high fidelity model uses a parallel processor capable CFD/CSD methodology. Both frameworks include an aeroacoustic simulation for prediction of noise. A synergistic process is developed that uses both frameworks together to build approximate models of important high fidelity metrics as functions of certain design variables. To test this process, a 4-bladed hingeless rotor model is used as a baseline. The design variables investigated include tip geometry and spanwise twist. Approximation models are built for high fidelity metrics related to rotor efficiency and vibration. Optimization using the approximation models found the designs having maximum rotor efficiency and minimum vibration. Various Pareto generation methods are used to find frontier designs between these two anchor designs. The Pareto anchors are tested in the high fidelity simulation and shown to be good designs, providing evidence that the process has merit. Ultimately, this process can be utilized by industry rotor designers with their existing tools to bring high fidelity analysis into the preliminary design stage of rotors.Ph.D.Committee Co-Chair: Dr. Dimitri Mavris; Committee Co-Chair: Dr. Lakshmi N. Sankar; Committee Member: Dr. Daniel P. Schrage; Committee Member: Dr. Kenneth S. Brentner; Committee Member: Dr. Mark Costell

Materials Classification Using Multichannel Radiographs

This work aims to validate previous exploratory work done to characterize materials by matching their attenuation profiles using a multichannel radiograph given an initial energy spectrum. The experiment was performed in order to evaluate the effects of noise on the resulting attenuation profiles, which was ignored in simulation. Spectrum measurements have also been collected from various materials of interest. Additionally, a MATLAB optimization algorithm has been applied to these candidate spectrum measurements in order to extract an estimate of the attenuation profile. Being able to characterize materials through this nondestructive method has an extensive range of applications for national security

HUMERAL RETROVERSION, CORRECTED RANGE-OF-MOTION, AND FAST SCORES IN COLLEGIATE BASEBALL PITCHERS

The purpose of this study was to examine the relationship between shoulder rotational range of motion, accounting for humeral retroversion (HR) and the Functional Arm Scale for Throwers (FAST). Nineteen male NCAA Division I collegiate baseball pitchers participated in the study and completed a modified FAST form. Humeral retroversion was measured and total rotational range of motion, corrected internal rotational range of motion, and corrected external rotational range of motion were calculated. No relationships were found between rotational ROM and the FAST score. The findings suggest further research needs to be performed on patient reported outcomes specific to changes in rotational ROM

Final Scientific Report Pecos Valley Biomass Cooperative Project

The goal of this study was to identify and select the best manure treatment technology to process manure form the 22 PVBC member dairies. It was determined that combustion of manure solids has potential, but it will be difficult to underwrite as the process has not been commercially proven

Advanced Stirling Convertor (ASC) Technology Maturation

The Advanced Stirling Convertor (ASC) development effort was initiated by NASA Glenn Research Center (GRC) with contractor Sunpower Inc. to develop high efficiency thermal-to-electric power conversion technology for NASA Radioisotope Power Systems. Early successful performance demonstrations led to the expansion of the project as well as adoption of the technology by the Department of Energy (DOE) and system integration contractor Lockheed Martin Space Systems Company as part of the Advanced Stirling Radioisotope Generator (ASRG) flight project. The ASRG integrates a pair of ASCs to convert the heat from a pair of General Purpose Heat Source (GPHS) modules into electrical power. The expanded NASA ASC effort included development of several generations of ASC prototypes or Engineering Units to help prepare the ASC technology and Sunpower for flight implementation. Sunpower later had two parallel contracts allowing the last of the NASA Engineering Units called ASC-E3 to serve as pathfinders for the ASC-F flight convertors being built for DOE. The ASC-E3 convertors utilized the ASC-F flight specifications and were built using the ASC-F design and process documentation. Shortly after the first ASC-F Pair achieved initial operation, due to budget constraints, the DOE ASRG flight development contract was terminated. NASA continues to invest in the development of Stirling RPS technology including continued production of the ASC-E3 convertors, seven of which have been delivered with one additional unit in production. Starting in FY2015, Stirling Convertor Technology Maturation has been reorganized as an element of the RPS Stirling Cycle Technology Development (SCTD) Project and long-term plans for continued Stirling technology advancement are in reformulation. This paper provides a status on the ASC project, an overview of advancements made in the design and production of the ASC at Sunpower, and a summary of acceptance tests, reliability tests, and tactical tests at NASA GRC that demonstrate the capabilities of the ASC

EFFECT OF TWO KINESIO TAPE TECHNIQUES ON KNEE KINEMATICS DURING A DROP JUMP TEST

This study investigated the effects of Kinesio® Tape on knee kinematics during a drop jump (DJ) test in 20 young women that had or were currently participating in competitive basketball or volleyball. Three taping conditions were randomly applied to the dominant leg of each participant: no tape (NT), gluteus medius (GM) facilitation, and spiral technique (ST). Multiple 3 x 2 RMANOVAs assessed the differences in peak knee flexion and abduction, and time to peak (TTP) angles, between taping conditions. No significant differences were found for peak knee angles or TTP, suggesting that GM and ST Kinesio® Tape applications did not alter measured knee kinematics during a DJ test. Any mitigation strategy should not depend on Kinesio® Tape alone and take a comprehensive approach that includes strength and neuromuscular training