Scale modeling has been commonly used for architectural acoustics but use in other noise control areas is nominal. Acoustic scale modeling theory is first reviewed and then feasibility for small-scale applications, such as is common in the electronics industry, is investigated. Three application cases are used to examine the viability. In the first example, a scale model is used to determine the insertion loss of a rectangular barrier. In the second example, the transmission loss through parallel tubes drilled through a cylinder is measured and results are compared to a 2.85 times scale model with good agreement. The third example is a rectangular cuboid with a smaller cylindrical well bored into it. A point source is placed above the cuboid. The transfer function was measured between positions on the top of the cylinder and inside of the cylindrical well. Treatments were then applied sequentially including a cylindrical barrier around the well, a membrane cover over the opening, and a layer of sound absorption over the well. Results are compared between the full scale and a 5.7 times scale model and correlation between the two is satisfactory.

Change in papillary muscle motion as a result of left ventricular (LV) remodeling after posterolateral myocardial infarction is thought to contribute to ischemic mitral regurgitation. A finite element (FE) model of the LV was created from magnetic resonance images acquired immediately before myocardial infarction and 8 weeks later in a cohort of 12 sheep. Severity of mitral regurgitation was rated by two-dimensional echocardiography and regurgitant volume was estimated using MRI. Of the cohort, 6 animals (DC) received hydrogel injection therapy shown to limit ventricular remodeling after myocardial infarction while the control group (MI) received a similar pattern of saline injections. LV pressure was determined by direct invasive measurement and volume was estimated from MRI. FE models of the LV for each animal included both healthy and infarct tissue regions as well as a simulated hydrogel injection pattern for the DC group. Constitutive model material parameters for each region in the FE model were assigned based on results from previous research. Invasive LV pressure measurements at end diastole and end systole were used as boundary conditions to drive model simulations for each animal. Passive stiffness (C) and active material parameter (Tmax) were adjusted to match MRI estimations of LV volume at end systole and end diastole. Nodal positions of the chordae tendineae (CT) were determined by measurements obtained from the excised heart of each animal at the terminal timepoint. Changes in CT nodal displacements between end systole and end diastole at 0 and 8-week timepoints were used to investigate the potential contribution of changes in papillary muscle motion to the progression of ischemic mitral regurgitation after myocardial infarction. Nodal displacements were broken down into radial, circumferential, and longitudinal components relative to the anatomy of the individual animal model. Model results highlighted an outward radial movement in the infarct region after 8 weeks in untreated animals, while radial direction of motion observed in the treated animal group was preserved relative to baseline. Circumferential displacement decreased in the remote region in the untreated animal group after 8 weeks but was preserved relative to baseline in the treated animal group. MRI estimates of regurgitant volume increased significantly in the untreated animal group after 8 weeks but did not increase in the treated group. The results of this analysis suggest that hydrogel injection treatment may serve to limit changes in papillary muscle motion and severity of mitral regurgitation after posterolateral myocardial infarction.

New reactor designs and the license extensions of the current reactors has created new condition monitoring challenges. A major challenge is the creation of a data-based model for a reactor that has never been built or operated and has no historical data. This is the motivation behind the creation of a hybrid modeling technique based on first principle models that adapts to include operating reactor data as it becomes available. An Adaptive Non-Parametric Model (ANPM) was developed for adaptive monitoring of small to medium size reactors (SMR) but would be applicable to all designs. Ideally, an adaptive model should have the ability to adapt to new operational conditions while maintaining the ability to differentiate faults from nominal conditions. This has been achieved by focusing on two main abilities. The first ability is to adjust the model to adapt from simulated conditions to actual operating conditions, and the second ability is to adapt to expanded operating conditions. In each case the system will not learn new conditions which represent faulted or degraded operations. The ANPM architecture is used to adapt the model's memory matrix from data from a First Principle Model (FPM) to data from actual system operation. This produces a more accurate model with the capability to adjust to system fluctuations. This newly developed adaptive modeling technique was tested with two pilot applications. The first application was a heat exchanger model that was simulated in both a low and high fidelity method in SIMULINK. The ANPM was applied to the heat exchanger and improved the monitoring performance over a first principle model by increasing the model accuracy from an average MSE of 0.1451 to 0.0028 over the range of operation. The second pilot application was a flow loop built at the University of Tennessee and simulated in SIMULINK. An improvement in monitoring system performance was observed with the accuracy of the model improving from an average MSE of 0.302 to an MSE of 0.013 over the adaptation range of operation. This research focused on the theory, development, and testing of the ANPM and the corresponding elements in the surveillance system.

The present research focuses on analyzing the possibility of implementing three dimensional woven composite (3DWC) materials in hip implants. The integration of 3DWCs in hip implants has the possibility to both extend the life-time and improve patient outcomes; by spatially varying mechanical properties to meet both biological needs as well as required mechanical loading. In this study, the bulk material properties of 3DWCs were varied based on woven composite architecture and determined using physics based models, which reflect the realistic geometries of fibers in compaction and preform. The multi-digital chain method combined with Extended Finite Elemental Analysis (XFEA) are adopted in this micro-analysis for composite design. Four different woven architectures with a combination of different existing biocompatible fiber and resins are considered in this study. The main objective is to assess the mechanical response of these biocompatible materials in the design of 3D woven architectures and determine their ability to match the required modulus at different regions of a hip implant. Results obtained show 3DWCs are viable candidates for this application. Multiple architectures and materials chosen, were able to achieve the desired mechanical response. Additional studies can use these results as a starting point and framework for further mechanical and biological testing.

Floating offshore wind turbines in deep waters offer significant advantages to onshore and near-shore wind turbines. However, due to the motion of floating platforms in response to wind and wave loading, the aerodynamics are substantially more complex. Traditional aerodynamic models and design codes do not adequately account for the floating platform dynamics to assess its effect on turbine loads and performance. Turbines must therefore be over designed due to loading uncertainty and are not fully optimized for their operating conditions. Previous research at the University of Massachusetts, Amherst developed the Wake Induced Dynamics Simulator, or WInDS, a free vortex wake model of wind turbines that explicitly includes the velocity components from platform motion. WInDS rigorously accounts for the unsteady interactions between the wind turbine rotor and its wake, however, as a potential flow model, the unsteady viscous response in the blade boundary layer is neglected. To address this concern, this thesis presents the development of a Leishman-Beddoes dynamic stall model integrated into WInDS. The stand-alone dynamic stall model was validated against two-dimensional unsteady data from the OSU pitch oscillation experiments and the coupled WInDS model was validated against three-dimensional data from NREL’s UAE Phase VI campaign. WInDS with dynamic stall shows substantial improvements in load predictions for both steady and unsteady conditions over the base version of WInDS. Furthermore, use of WInDS with the dynamic stall model should provide the necessary aerodynamic model fidelity for future research and design work on floating offshore wind turbines.

The problem of calculating iso-surface statistics in turbulent flows is interesting for a number of reasons, some of them being combustion modeling, entrainment through turbulent/non-turbulent interfaces, calculating mass flux through iso-scalar surfaces and mapping of scalar fields. A fundamental effect of fuid turbulence is to wrinkle scalar iso-surfaces. A review of the literature shows that iso-surface calculations have primarily been done with geometric methods, which have challenges when used to calculate surfaces that have high complexity, such as in turbulent flows. In this thesis, we propose an alternative integral method and test it against analytical solutions. We present a parallelized algorithm and code to enable in-simulation calculation of isosurface area. We then use this code to calculate area statistics for data obtained from Direct Numerical Simulations and make predictions about the variation of the iso-scalar surface area with Taylor Peclet numbers between 9.8 and 4429 and Taylor Reynolds numbers between 98 and 633.

With the automotive industry ever striving to push the limits of fuel efficiency, the Shell EcoMarathon offers a glimpse into this energy conserving mindset by challenging engineering students around the world to design and build ultra-efficient vehicles to compete regionally. This requires synchronization of engineering fields to ensure that the vehicle and powertrain system work in parallel to achieve similar goals. The goal for Cal Poly – San Luis Obispo’s EcoMarathon vehicle for the 2015 competition is to analyze the unique operating mode that the powertrain undergoes during competition and improve their current package to increase fuel efficiency. In this study, fuel delivery, ignition timing and engine temperature are experimentally varied to observe trends in steady state fuel consumption. A developmental simulation is then implemented with these trends to analyze potential differences in transient and steady state tuning targets. The engine is then tuned to finalized tuning targets and performance compared with benchmark values.

Spacecraft testing includes acoustics, vibrations, and thermal vacuum. Cal Poly’s Space Environments Lab is equipped with multiple vacuum chambers, but no thermal vacuum chamber. The purpose of this thesis is to incorporate an ATS Chiller system with the HVEC vacuum chamber so students are able to experiment with a thermal vacuum chamber. The ATS Chiller had leaky pipes that needed to be refurbished and a shroud was implemented to improve thermal capabilities of the system. The full system was able to reach temperatures as low as -38ºC and as high as 58ºC at a pressure of 10-6 Torr. The ATS Chiller was able to absorb up to 500W of heat dissipation from a component mounted to the platen inside of the vacuum chamber. Thermal modeling of the apparatus was performed in Thermal Desktop. The model was incorporated with the test data to extract interface resistance information between connected surfaces. Another model is used to analyze a theoretical component inside the apparatus to evaluate mounting methods and determine theoretical temperatures of the component. The model adjusts for material properties, including thermal conductivity and emissivity to accurately simulate testing conditions within +/- 3ºC. Platen and shroud adjustments were able to accommodate a peak bake out temperature of 130±2.2℃ of any component without damage to the system. Three temperature cycles were performed by the thermal vacuum chamber to reach extreme temperatures of 58℃ and -38. A 300 Watt heater was used to simulate component heat dissipation for the duration of the test. Furthermore, this thesis lays out further possibilities for thermal testing using the HVEC Vacuum chamber and ATS chiller as a thermal vacuum chamber.

Creating a bicycle with a rideable geometry is more complicated than it may appear, with today’s mainstay designs having evolved through years of iteration. This slow evolution coupled with the bicycle’s intricate mechanical system has lead most builders to base their new geometries off of previous work rather than expand into new design spaces. This crutch can lead to slow bicycle iteration rates, often causing bicycles to all look about the same. To combat this, several bicycle design models have been created over the years, with each attempting to define a bicycle’s handling characteristics given its physical geometry. However, these models often analyze a single bicycle at a time, and as such, using them in an iterative design process can be cumbersome. This work seeks to improve an existing model used by the Cal Poly Mechanical Engineering department such that it can be used in a proactive, iterative fashion (as opposed to the reactive, single-design paradigm that it currently supports). This is accomplished by expanding the model’s inputs to include more bicycle components as well as differently sized riders. This augmented model is then incorporated into several search platforms ranging from a brute-force implementation to several variants using genetic algorithm concepts. These models allow the designer to specify a bicycle design search space as well as a set of riders upfront, from which the algorithms search out and find strong candidate designs to return to the user. This in turn reduces the overhead on the designer while also potentially discovering new bicycle designs which had not been considered previously viable. Finally, a front-end was created to make it easier for the user to access these algorithms and their results.

The Department of Energy (DOE) confirmed Team Solar Cal Poly from California Polytechnic State University, San Luis Obispo, as a competitor in the 2015 Solar Decathlon in February 2014. The Solar Decathlon is a biennial collegiate competition to construct a net-zero home and operate it for a week of “normal use”. Solar Cal Poly needed assistance with passive and active HVAC systems for the design, and thermal load models. The competition will take place in Irvine, CA [33.67⁰, 117.82⁰ W] from September 27 – October 3, 2015. After the completion, a potential final location for the house will be Santa Ynez, CA [34.61⁰ N, 120.09⁰ W]. Ms. Willis assisted with a climate study for both locations and research passive and active HVAC systems and design elements for Team Solar Cal Poly. She modeled the final summer design in DesignBuilder to calculate the heating and cooling loads. The heating load was calculated to be 26.7 kBTU/h. The cooling load was calculated to be 2-tons. A mini-split HVAC system was selected for the final summer design based off the calculated heating and cooling loads. For this design, the Fujitsu Hybrid Halcyon Flex met the minimum requirements, and was a multi-zone system that could condition all three major spaces of the design. This report provides a summary of information and the basic design process for future Solar Decathlon designs considerations.