Engineering Commons^™

Center Pivot Sprinkler Distribution Uniformity Impacts On The Spatial Variability Of Evapotranspiration, Daniel Howes, Sean Ellenson, Lucas Hoffmann, Franklin Gaudi

BioResource and Agricultural Engineering

Understanding variable evapotranspiration (ET) throughout a field can help maximize yield on a per-acre basis, as well as assist with proper irrigation scheduling. The results from this study indicate that irrigation system distribution uniformity (DU) has a significant effect on the uniformity of ET during water-stressed periods. The study site involved intensely managed forage (alfalfa and winter grain hay) irrigated by center pivots being supplied with reclaimed water near Palmdale, California. During spring and early summer 2007 the center pivots were operating under deficit irrigation. In 2010, after the installation of reservoirs, water was applied to meet full evapotranspiration (ETc) …

On The Interaction Of A Racing Car Front Wing And Exposed Wheel, S. Diasinos, G. Doig, T.J. Barber

Aerospace Engineering

A numerical investigation of generic open-wheel racing car wing and wheel geometry has been conducted, using original sub-scale experimental data for validation. It was determined that there are three main interactions that may occur, identifiable by the path that the main and secondary wing vortices take around the wheel. Interaction ‘A’ occurs when the main and secondary wing vortices both travel outboard of the wheel; interaction ‘B’ is obtained when only the main wing vortex passes inboard of the wheel; while interaction ‘C’ sees both wing vortices travel inboard of the wheel. The different interactions are achieved when geometric changes …

Flow Compressibility Effects Around An Open-Wheel Racing Car, J. Keogh, G. Doig, S. Diasinos

Aerospace Engineering

A numerical investigation has been conducted into the influence of flow compressibility effects around an open-wheeled racing car. A geometry was created to comply with 2012 F1 regulations. Incompressible and compressible CFD simulations were compared-firstly with models which maintained Reynolds number as Mach number increased, and secondly allowing Mach number and Reynolds number to increase together as they would on track. Results demonstrated significant changes to predicted aerodynamic performance even below Mach 0·15. While the full car coefficients differed by a few percent, individual components (particularly the rear wheels and the floor/ diffuser area) showed discrepancies of over 10% at …

Modernization Of The Walker River Irrigation District Water Gauges, Stuart Styles, Robert C. Bryan, Kenneth C. Spooner

BioResource and Agricultural Engineering

The Irrigation Training and Research Center (ITRC) and Walker River Irrigation District (WRID) collaborated on WRID’s Water Gauge Improvement Project with support from the Bureau of Reclamation, U.S. Department of Interior in Carson City, Nevada. This paper presents a summary of the proposed plan and implementation for improving water gauges in WRID with strategic engineering recommendations for new hardware and control equipment; water management strategies; flow measurement devices; and integration of a new district-wide SCADA system. Field investigations and engineering analyses were carried out by the ITRC in 2009 to inspect existing WRID infrastructure, to review current operational procedures, and …

Integrating Remote Sensing Of Evapotranspiration With Applied Water To Target Potential Water Conservation Projects In Watersheds, Daniel J. Howes, Stuart Styles

BioResource and Agricultural Engineering

The overall purpose of the project is to develop a methodology for watershed managers to successfully target and release recommendations to growers that could benefit from improved on-farm irrigation management. Initially it was thought that the methodology could rely on remote sensing of actual crop evapotranspiration, effective rainfall estimates, and water application information (pumped volumes and surface water deliveries) to simply evaluate if fields and farms that applied significantly more water than plants needed could be identified. However, it became clear that, in this region specifically, additional information on water quality, crop sensitivity to salinity, and an assumed good irrigation …

Evaluating Net Groundwater Use From Remotely Sensed Evapotranspiration And Water Delivery Information, Daniel J. Howes, Charles M. Burt, Lucas Hoffman

BioResource and Agricultural Engineering

A detailed, comprehensive, and accurate identification of groundwater aquifer properties will likely never be fully achieved because of the high degree of variability and costs that testing involves. Furthermore, accurate estimates of boundary conditions are essential for groundwater modeling so that investigations of improved management scenarios can be conducted. The lack of key input values at the ground surface boundary limits the ability to accurately assess aquifer dynamics. Of major importance is actual evapotranspiration (water consumption or the loss of water to the atmosphere through transpiration and evaporation). The Irrigation Training and Research Center (ITRC) modified remotely sensed satellite imagery …

Winegrape Vineyards And Winery Operations: Energy Efficiency/ Sustainability And Expansion, Stuart Styles, Sierra Layous, Sarah Crable

BioResource and Agricultural Engineering

Southern California Edison (SCE) provides utility services to the greater southern California area. Vineyards and wineries exist throughout the region, and historical data suggests that that they largely do not utilize incentive programs offered by the utility.

As the first phase in a larger study, the Irrigation Training & Research Center (ITRC), located at the California Polytechnic State University, San Luis Obispo, completed a characterization of the vineyard and winery sector as it pertains to energy and water usage in SCE’s service area, including the following major tasks:

1. Identification of vineyard and winery demographics in SCE’s service area.
2. Identification of …

A Control-Chart Based Method For Solder Joint Crack Detection, Jianbiao Pan

Industrial and Manufacturing Engineering

Many researchers have used different failure criteria in published solder joint reliability studies. Since the reported timeto-failure would be different if different failure criteria were used, it would be difficult to compare the reported reliability life of solder joints from one study to another. The purpose of this study is to evaluate the effect of failure criteria on the reported thermal fatigue life and determine which failure criterion could detect failure sooner. First, the application of the control-chart-based method in a thermal cycling reliability study is described. The reported time-to-failure data were then compared based on four different failure criteria: …

A Prototype Microwave Cavity Control Circuit For Use In Next Generation Free Electron Laser, Josh Thompson, Peter Neal Barrina, Jiayi Jiang, Joe Frisch, Steve Smith, Daniel Van Winkle

STAR Program Research Presentations

One of the current programs at SLAC National Accelerator Laboratory is the Linac Coherent Light Source, or LCLS. Using the existing hardware of the last third of their linear accelerator (or “linac”), SLAC has created one of the most energetic X-ray free electron lasers (or “FEL”). Since 2009, LCLS has used this FEL to perform a wide range of experiments across all sciences, most notably ultrafast filming at the molecular scale. As requests for beam-time with this laser increases, SLAC is purposing a linac upgrade to better match this demand. This upgrade, named LCLS-II, will replace existing copper radio frequency …

Foss Big Data Storage Solution, Gary L. Jaffe

STAR Program Research Presentations

Utilizing the AERO Institute as an IT test bed or “sandbox”, a small-agile development team will design, build, and test a data management storage system to support post processing of archived and in-flight data collected with the Piccolo flight control system and Compact Fiber Optic Sensing System (C-FOSS). Both systems are integrated on the APV3 aircraft, a small remote-operated vehicle. Due to the amount of data collected from C-FOSS, a system will be designed to sort and organize large data sets. An open-source database will be explored as a viable solution to manage large data loads and provide multi-cluster system …

Local Buckling Behavior Of Round Steel Tubes Subjected To Compressive Loads, Joseph Moore, Ben Fell

STAR Program Research Presentations

This project will investigate the local buckling induced fracture behavior of round steel tubes subjected to axial compressive loads, representative of observed failures in buried pipelines during seismic events. Nine initial tests will be conducted across three lengths of round steel tube: 8”, 12”, and 20”. Another twelve tests will be conducted on the lengths of 12” and 20” to test varying initial compressive force upon the round steel tubes. Three D/t ratios will be considered for each length of round steel tube: 52.6, 78.9, and 121.2. To verify the material properties of the test specimens an ancillary tensile coupon …

Transonic And Supersonic Ground Effect Aerodynamics, Graham Doig

Aerospace Engineering

A review of recent and historical work in the field of transonic and supersonic ground effect aerodynamics has been conducted, focussing on applied research on wings and aircraft, present and future ground transportation, projectiles, rocket sleds and other related bodies which travel in close ground proximity in the compressible regime. Methods for ground testing are described and evaluated, noting that wind tunnel testing is best performed with a symmetry model in the absence of a moving ground; sled or rail testing is ultimately preferable, though considerably more expensive. Findings are reported on shock-related ground influence on aerodynamic forces and moments …

Foss Big Data Storage Solution, Nurdeen Salami

STAR Program Research Presentations

NASA projects require a reliable approach to store large volumes of data. Accordingly, it is crucial to adopt a lightweight, reliable, and scalable database. Current NASA databases bear costly license fees with undesirable speed and flexibility. The purpose of utilizing the AERO Institute as an IT test bed, or “Sandbox,” is to design, build, test, and implement software solutions prior to transfer to NASA projects. Cassandra coupled with the Astyanax API is a viable solution for storing big data. Store a minimum of 2GB of C-FOSS data in multiple file formats (.csv, .log, .xml, and .jpg). Use benchmark tests to …

Particle Image Velocimetry Of Transverse Jets In Crossflow, Jesse K. Tsai, Kayla Kuzmich, David Forliti, Kriss Vanderhyde, Nils Sedano

STAR Program Research Presentations

The jet in crossflow (JICF) has been an ongoing study for the past several decades with applications in the field of fluid mechanics. This particular flow field produces vortical structures tied to the entrainment and mixing of two separate fluids. Research of the JICF seeks to determine a model and trajectory scaling law for future designs. This will help future designers to optimize the mixing and homogeneity of the two fluids to decrease emissions from pollutants, make ignition easier, and improve combustion efficiency of rockets.

Our experiment will employ Particle Image Velocimetry (PIV) to determine the fluid motion of the …

Space Race: Capturing An Orbiting Sample And A Nation’S Imagination, Stephanie La Liberte, Andrew Chavarin, Shubham Gogna, C. Daniel Thomas, Vy Phung, Gabriel Udomkesmalee

STAR Program Research Presentations

A proposed architecture for future planetary sample return missions would consist of capturing on-orbit a sample container (collected from the surface of a planetary body and launched into space) and transferring the sample container into an earth return/reentry capsule. A challenge to this proposed architecture is integrating space applicable sensor technologies with sufficient capturing devices. While useful technologies on Earth, Earth-related rendezvous/capture technologies, such as magnetic field sensors, sound-based sensors, and Earth orbit-based radios like GPS, are not applicable to space. Inspired by the in-orbit sample capture challenge, NASA JPL has designed the Space Rendezvous And Capture Experiment (Space RACE). …

Does A Plastron Improve Heat Transfer?, Madani A. Khan, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Superamphiphobic surfaces strongly repel both water and oils. In this work, aluminum coupons are processed by sanding with various grit of sand paper to impart microscale roughness. Subsequent submersion of the aluminum substrate in boiling water grows nanoscale grass-like structures. The oxide layer of Al is slightly soluble in water. During a fast diffusion/equilibrium, Al₂O₃ nanograss grows on the surface. A low energy coating is then deposited on the surface. The micro and nanoscale features create re-entrant structures that trap air enabling contact liquid to be in a Cassie-Baxter state. Superamphiphobicity of the samples were confirmed by …

Organic-Based Microwave Frequency Absorbers Using Corn Stover, Ben Smythe, Sean Casserly, Dean Arakaki

Electrical Engineering

Commercial antenna test chambers (anechoic) currently use polyurethane foam absorbers on chamber interiors to eliminate undesired radio-frequency (RF) reflections. While effectively absorbing microwave signals, polyurethane material particulates over time adding contaminants to clean rooms and reducing absorber lifetime. These absorbers also release toxic gas when operating under high temperatures and pose a health risk to direct-contact personnel. This paper presents reflectivity analysis and performance of alternative organic-based (corn stover) microwave frequency absorbers for use in anechoic chambers. These absorbers are composed of renewable materials and eliminate the toxic gas release problem for polyurethane materials under high power test conditions. Preliminary …

Multi-Technique Broadband Microstrip Patch Antenna Design, Daniel Colles, Dean Arakaki

Electrical Engineering

Microstrip patch antennas offer low profile and small footprint advantages, but limited operating bandwidth. Substantial research focuses on broadband techniques. This paper presents the design, simulation, fabrication, and characterization of a 30% bandwidth microstrip patch antenna that incorporates multiple broadband techniques while minimizing footprint area. Methods include patch shape, dielectric thickness, and coupling slot optimization, with capacitively-coupled L-probe feeds. The final design incorporates an electrically thick dielectric and circular-E patch geometry. Microstrip L-probe feed and coupling slot dimensions were optimized via HFSS simulations. The final design was fabricated, and then tested in an anechoic chamber. The new design has measured …

Cost Performance Dynamics In Lean Production Leveling, Ahmed Deif, Hoda Elmaraghy

Industrial Technology and Packaging

Balancing of production systems is one of the main lean manufacturing principles as it reduces in-process storage and related forms of waste. A dynamic systems approach is proposed to investigate challenges of implementing production leveling and associated costs. A lean cell producing at takt time is modeled using system dynamics. The model captures various lean tools influencing production leveling and their implications. Comparative cost analysis between various leveling implementation policies for stochastic demand with multiple products is conducted. Results showed that determining the most feasible leveling policy is highly dictated by both the cost and limitations of capacity scalability. In …

The Aerodynamics Of A Cornering Inverted Wing In Ground Effect, James Keogh, Graham Doig, Tracie J. Barber, Sammy Diasinos

Aerospace Engineering

For racing car configurations an inverted wing produces negative lift that allows increased levels of acceleration to be maintained through corners. Routine aerodynamic analysis, however, will typically be in the straight-line condition. A numerical analysis of the inverted T026 wing geometry through the curved path of a constant radius corner was conducted. The asymmetrical properties of the oncoming flow resulted in the introduction of a rolling and yawing moment along the span, as well as side-force. Yaw angle, flow curvature and a velocity gradient resulted in changes to the pressure distribution over the wing surface. Primary vortex behaviour was observed …

Application Of Kriging To Motorsport Aerodynamic Analysis, Matthew Cruickshank, Graham Doig

Aerospace Engineering

Aerodynamic analysis in motorsport is conducted using three methods, computational, scaled experimental and full-scale operational. However, the varying fidelity, different sampling resolutions and unavoidable errors of each technique make valid comparisons between datasets from each method difficult and time consuming. Kriging is a geostatistical method to estimate values within a data field by examining and applying the trends of the dataset. This research examines how such techniques can be used to aid comparison between aerodynamic measurements of a race car. It examines how kriging can be used to transform discrete measurements, of varying fidelity and sampling resolution, into semi-continuous measurements, …

Computational Simulation Of An Altitude Adaptive Nozzle Concept, K. Schomberg, G. Doig, J. Olsen

Aerospace Engineering

A computational analysis of an annular converging-diverging (CD) and an altitude adaptive expansion-deflection (ED) nozzle is presented. Numerical results were generated using a 2D axisymmetric, pressure-coupled solver in conjunction with the Spalart-Allmaras turbulence closure model and second order spatial discretisation schemes. Results were recorded over a theoretical altitude range and compared to experimental static pressure readings and schlieren images. The correlation between numerical and experimental static pressure values was high for all cases. Comparison of schlieren imagery outlined the large variety of flow regions within the ED nozzle flow field. The interactions between these regions were highly sensitive to turbulence …

Fundamental Studies Of Vortices Induced By A Vortex-Generator For Automotive Applications, Asiful Islam, Graham Doig

Aerospace Engineering

For automotive applications, passive flow control devices can be used to reduce, delay or prevent flow separation. This study explores the nature of vortex generation and behaviour, numerically and experimentally, for a simple geometry at a Reynolds Number (Rex) of 5×105 and 1.945×106. The setup comprised a triangular vane vortex-generator mounted on a shallow ramp referenced from literature. Flow over the isolated ramp was validated with past experimental particle-image-velocimetry (PIV) data, which also highlighted the relative performance of various turbulence models. A parametric study was undertaken with the vane orientation defined by an angle-of-attack (β) and stream-wise location (xedge/xVG). These …

Implementation Of New Irrigation Protocols On Strawberry Transplants On The California Central Coast, Stuart Styles, Kerilyn Ambrosini

BioResource and Agricultural Engineering

For the past five growing seasons, the Cal Poly Irrigation Training and Research Center (ITRC) has conducted research on water use, salinity levels and various other factors related to strawberry transplant establishment. This report summarizes research that can be found online: www.itrc.org/projects.htm.

The project’s goal was to develop an analysis of irrigation practices of the strawberry growers on the central coast of California, primarily during the establishment of transplants. From the analysis, sprinkler use reduction methods were developed. These methods conserve water, save pumping costs, and reduce the runoff that can potentially contaminate local waterways. California growers contributed control and …

Pressure Recorders: Low-Cost, Robust, Low-Battery-Use Field Measurement Techniques For Trending Water Pressure, Stuart Styles, Kerilyn Ambrosini

BioResource and Agricultural Engineering

Water users across California need robust, low-cost water level/pressure sensors with integrated data loggers for a high level of precision and accuracy. The Cal Poly Irrigation Training and Research Center (ITRC) has installed Telog Instruments devices in California and Nevada over the last 12 years to provide a performance review of the devices. The two devices focused on were the Telog Instruments WLS-31 Level Tracker and LPR-31i Line Pressure Recorder. Over the study period, ITRC has collected several sets of data in varying situations. After 11 years of use on a reservoir, the two Telog WLS-31 units had a 1% …

Dynamic Modelling Of Impact Of Lean Policies On Production Levelling Feasibility, Hoda Elmaraghy, Ahmed Deif

Industrial Technology and Packaging

A dynamic systems approach is proposed to investigate challenges of implementing production leveling and associated costs. A model of a lean cell is developed using system dynamics. The model captures various lean tools influencing production leveling. Comparative cost analysis between various leveling implementation policies for stochastic demand with multiple products is conducted. Results showed that determining the most feasible leveling policy is highly dictated by both capacity scalability cost and limitations. The developed model and revealed insights can help lean practitioners to better decide on when and how to implement production leveling as well as determine production lots sizes.

Impact Of Dynamic Capacity Policies On Wip Level In Mix Leveling Lean Environment, Ahmed Deif, Hoda Elmaraghy

Industrial Technology and Packaging

Balancing demand's product variety in production planning is one aspect of variety management challenge. This phenomenon is described in lean systems as mix leveling. This paper approach product mix leveling problem from a dynamic perspective. A system dynamics model is developed to explore the dynamics associated with the WIP level performance at different mix leveling policies in a lean environment. The system captures different lean tools and policies. Results showed that the best WIP performance is sensitive to both the degree of lean tools implementation as well as the capacity scalability level of the system. The presented analysis showed that …

Dynamic Lean Assessment For Takt Time Implementation, Rehab M. Ali, Ahmed M. Deif

Industrial Technology and Packaging

Increasing volatility, global competitiveness, and sales crisis all force the manufacturers to commit to the journey of world-class manufacturing performance via adopting “lean systems” to enable economic success in difficult times. Among the journey to lean, one of the hardest steps is measuring the progress of lean polices implementation especially in this highly dynamic market. This paper presents a dynamic model to evaluate the degree of leanness in manufacturing firms. The model is based on system dynamics approach and presents a “leanness score” for the manufacturing system. In addition, it examines the dynamics associated with the application of “One-piece flow” …

An Integrated Approach To Assess Manufacturing Greeness Level, Ahmed H. Salen, Ahmed Deif

Industrial Technology and Packaging

This paper proposes an integrated approach for relative greenness level assessment in selected manufacturing industries at the system level. The approach builds on existing methodologies to develop a multi-layer tool box called “Greenometer” which focus on the strategic comparison for cross industries evaluation as well as tactical comparison for intra-industries. The assessment tool captures the fundamental evaluation parameters of green manufacturing namely; Environment, Energy, Resources and Economy. In addition, the Greenometer employs geometric mean method (GMM) for the strategic layer and data envelopment analysis (DEA) for the tactical layer and will be used for different selected manufacturing disciplines. The proposed …

Routing Strategies For Emergency Management Decision Support Systems During Evacuation, Joseph Yu, Anurag Pande, N. Nezamuddin, Vinayak Dixit, Frances Edwards

Civil and Environmental Engineering

Simulation studies of urban transportation networks have been increasingly applied to evacuation planning. The level of detail provided within a traffic simulation model allows for devising strategies for evacuation and emergency response. In this research, simulation model of downtown San Jose, California, transportation network is developed to evaluate the efficiency of the evacuation process under hypothetical scenarios. Although the scenarios evaluated herein are not exhaustive, they demonstrate the potential of the simulation approach for managing traffic engineering aspects of the emergency response. The scenarios described here include the use of contraflow lanes, traffic incidents on the network, and a modal …