Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

144,662 Full-Text Articles 166,242 Authors 56,080,941 Downloads 298 Institutions

All Articles in Engineering

Faceted Search

144,662 full-text articles. Page 5 of 4147.

Long And Short-Range Air Navigation On Spherical Earth, Nihad E. Daidzic 2019 AAR Aerospace Consulting, LLC

Long And Short-Range Air Navigation On Spherical Earth, Nihad E. Daidzic

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

Global range air navigation implies non-stop flight between any two airports on Earth. Such effort would require airplanes with the operational air range of at least 12,500 NM which is about 40-60% longer than anything existing in commercial air transport today. Air transportation economy requires flying shortest distance, which in the case of spherical Earth are Orthodrome arcs. Rhumb-line navigation has little practical use in long-range flights, but has been presented for historical reasons and for comparison. Database of about 50 major international airports from every corner of the world has been designed and used in testing and route ...


Modeling And Computation Of The Maximum Braking Energy Speed For Transport Category Airplanes, Nihad E. Daidzic 2019 AAR Aerospace Consulting, LLC

Modeling And Computation Of The Maximum Braking Energy Speed For Transport Category Airplanes, Nihad E. Daidzic

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

Transport-category or FAR/CS 25 certified airplanes may occasionally become braking energy capacity limited. Such limitation may exist when heavy airplanes are departing airports at high-density altitudes, on relatively long runways, and/or possibly with some tailwind component. A maximum braking energy VMBE speed exists which may limit the maximum allowable takeoff decision/action speed V1. The ever-existing possibility of high-speed rejected takeoff in such conditions may also limit the airplane gross weight for declared available distances. To gain deeper insights and acquire better understanding of the topic, a theoretical model of the maximum braking energy and the related VMBE ...


Improving Airplane Touchdown Control By Utilizing The Adverse Elevator Effect, Nihad E. Daidzic Ph.D., Sc.D. 2019 AAR Aerospace Consulting, LLC

Improving Airplane Touchdown Control By Utilizing The Adverse Elevator Effect, Nihad E. Daidzic Ph.D., Sc.D.

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

The main objective of this original research article is to understand the short-term dynamic behavior of the transport-category airplane during landing flare elevator control application. Increasing the pitch angle to arrest the sink rate, the elevator will have to produce negative lift to rotate the airplane’s nose upward. This has an immediate adverse effect of initially accelerating airplane downward. A mathematical model of landing flare based on the flat-Earth longitudinal dynamics of rigid airplane was developed which is realistic only on very short time-scales as pitch stiffness and damping were neglected. Pilot control scenarios using impulse and step elevator ...


Global Optimized Isothermal And Nonlinear Models Of Earth’S Standard Atmosphere, Nihad E. Daidzic, Ph.D., 2019 AAR Aerospace Consulting, LLC

Global Optimized Isothermal And Nonlinear Models Of Earth’S Standard Atmosphere, Nihad E. Daidzic, Ph.D.,

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

Both, a global isothermal temperature model and a nonlinear quadratic temperature model of the ISA was developed and presented here. Constrained optimization techniques in conjunction with the least-square-root approximations were used to design best-fit isothermal models for ISA pressure and density changes up to 47 geopotential km for NLPAM, and 86 orthometric km for ISOAM respectively. The mass of the dry atmosphere and the relevant fractional-mass scale heights have been computed utilizing the very accurate eight-point Gauss-Legendre numerical quadrature for both ISOAM and NLPAM. Both, the ISOAM and the NLPAM represent viable alternatives to ISA in many practical applications and ...


Estimation Of Performance Airspeeds For High-Bypass Turbofans Equipped Transport-Category Airplanes, Nihad E. Daidzic 2019 AAR Aerospace Consulting, LLC

Estimation Of Performance Airspeeds For High-Bypass Turbofans Equipped Transport-Category Airplanes, Nihad E. Daidzic

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

Conventional Mach-independent subsonic drag polar does not replicate the real airplane drag characteristics exactly and especially not in the drag-divergence region due to shock-induced transonic wave drag. High-bypass turbofan thrust is a complicated function of many parameters that eludes accurate predictions for the entire operating envelope and must be experimentally verified. Fuel laws are also complicated functions of many parameters which make optimization and economic analysis difficult and uncertain in the conceptual design phase. Nevertheless, mathematical models and predictions have its important place in aircraft development, design, and optimization. In this work, airspeed-dependent turbofan thrust and the new fuel-law model ...


Efficient General Computational Method For Estimation Of Standard Atmosphere Parameters, Nihad E. Daidzic Ph.D., Sc.D. 2019 AAR Aerospace Consulting, LLC

Efficient General Computational Method For Estimation Of Standard Atmosphere Parameters, Nihad E. Daidzic Ph.D., Sc.D.

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

Knowledge of standard air temperature, pressure, density, speed of sound, and viscosity as a function of altitude is essential information in aircraft design, performance testing, pressure altimeter calibration, and several other aeronautical engineering and aviation science applications. A new efficient computational method for rapid calculations of standard atmospheric parameters up to 86 orthometric km is presented. Additionally, mass and weight of each standard atmospheric layer were calculated using a numerical integration method. The sum of all fractional masses and weights represents the total mass and weight of Earth’s atmosphere. The results obtained here agree well with measurements and models ...


Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D. 2019 AAR Aerospace Consulting, LLC

Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D.

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

No commercial airplane in service today is able to fly half great-circle distances over the globe and achieve the non-stop or the global range to any antipodal location on Earth. A subsonic jetliner has the optimum cruising speed at Mach numbers approaching the drag divergence Mach number while still preserving relatively high aerodynamic efficiency. Various fuel-flow laws were used to investigate the cruise performance of subsonic and supersonic aircraft. The effect of wind and aircraft weight and how it affects the optimal cruising airspeed was investigated. Of all different operational cruising techniques, the cruise-climb at high Mach numbers is the ...


Design Of Dc-Link Vscf Ac Electrical Power System For The Embraer 190/195 Aircraft, Eduardo Francis Carvalho Freitas, Nihad E. Daidzic 2019 ETEP – Faculdade de Tecnologia de São José dos Campos, Brazil

Design Of Dc-Link Vscf Ac Electrical Power System For The Embraer 190/195 Aircraft, Eduardo Francis Carvalho Freitas, Nihad E. Daidzic

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

A proposed novel DC-Link VSCF AC-DC-AC electrical power system converter for Embraer 190/195 transport category airplane is presented. The proposed converter could replace the existing conventional system based on the CSCF IDGs. Several contemporary production airplanes already have VSCF as a major or backup source of electrical power. Problems existed with the older VSCF systems in the past; however, the switched power electronics and digital controllers have matured and can be now, in our opinion, safely integrated and replace existing constant-speed hydraulic transmissions powering CSCF AC generators. IGBT power transistors for medium-level power conversion and relatively fast efficient switching ...


Determination Of Rejected Landing Roll Runway Point-Of-No-Return And Go-Around In Transport Category Airplanes, Nihad E. Daidzic, Ph.D., Sc.D. 2019 AAR Aerospace Consulting, LLC

Determination Of Rejected Landing Roll Runway Point-Of-No-Return And Go-Around In Transport Category Airplanes, Nihad E. Daidzic, Ph.D., Sc.D.

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

The decelerate-accelerate-takeoff maneuver in transport category airplanes has been discussed. Mathematical model based on total energy conservation has been used to calculate the rejected landing point-of-no-return on a runway which will still enable the airplane to safely execute go-around and achieve regulatory screen heights and takeoff safety speeds. After this point has been exceeded or below the point-of-no-return speed no go-around should ever be considered. Landing long and fast and/or decelerating on slippery runways may very well result in an overrun which could be prevented if the go-around is attempted before reaching this critical runway point. The point-of-no-return on ...


A Contribution Toward Better Understanding Of Overbanking Tendency In Fixed-Wing Aircraft, Nihad E. Daidzic 2019 AAR Aerospace Consulting, LLC

A Contribution Toward Better Understanding Of Overbanking Tendency In Fixed-Wing Aircraft, Nihad E. Daidzic

Nihad E. Daidzic, Dr.-Ing., D.Sc., ATP, CFII, MEI

The phenomenon of overbanking tendency for a rigid-body, fixed-wing aircraft is investigated. Overbanking tendency is defined as a spontaneous, unbalanced rolling moment that keeps increasing an airplane’s bank angle in steep turns and must be arrested by opposite aileron action. As stated by the Federal Aviation Administration, the overbanking tendency may lead to a loss of control, especially in instrument meteorological conditions. It was found in this study that the speed differential over wing halves in horizontal turns indeed creates a rolling moment that achieves maximum values for bank angles between 45 and 55 degrees. However, this induced rolling ...


Reimagining Icarus: Ethics, Law And Policy Considerations For Commercial Human Spaceflight, Sara M. Langston 2019 Senmurv Consulting LLC

Reimagining Icarus: Ethics, Law And Policy Considerations For Commercial Human Spaceflight, Sara M. Langston

Sara Langston

Commercial human spaceflight presents an area for engaging novel human activity and objectives, to include space exploration, entertainment, transportation and extraterrestrial resource acquisition. The inherent dangers and lack of scientific and medical certainty involved however raise interrelated questions of ethics, bioethics, law and public policy. This is particularly the case with spaceflight participant (SFP) screening, selection, and commercial human spaceflight activities where regulations are currently silent or lacking. In the absence of established law, ethics can play an important role by informing industry standards, policies and best practices. Understanding the fundamental ethical values at stake in the application of new ...


Fluid Transport In Porous Media For Engineering Applications, Eric M. Benner 2019 University of New Mexico

Fluid Transport In Porous Media For Engineering Applications, Eric M. Benner

Chemical and Biological Engineering ETDs

This doctoral dissertation presents three topics in modeling fluid transport through porous media used in engineering applications. The results provide insights into the design of fuel cell components, catalyst and drug delivery particles, and aluminum- based materials. Analytical and computational methods are utilized for the modeling of the systems of interest. Theoretical analysis of capillary-driven transport in porous media show that both geometric and evaporation effects significantly change the time dependent behavior of liquid imbibition and give a steady state flux into the medium. The evaporation–capillary number is significant in determining the time-dependent behavior of capillary flows in porous ...


Self-Driving Cars: Evaluation Of Deep Learning Techniques For Object Detection In Different Driving Conditions, Ramesh Simhambhatla, Kevin Okiah, Shravan Kuchkula, Robert Slater 2019 SMU

Self-Driving Cars: Evaluation Of Deep Learning Techniques For Object Detection In Different Driving Conditions, Ramesh Simhambhatla, Kevin Okiah, Shravan Kuchkula, Robert Slater

SMU Data Science Review

Deep Learning has revolutionized Computer Vision, and it is the core technology behind capabilities of a self-driving car. Convolutional Neural Networks (CNNs) are at the heart of this deep learning revolution for improving the task of object detection. A number of successful object detection systems have been proposed in recent years that are based on CNNs. In this paper, an empirical evaluation of three recent meta-architectures: SSD (Single Shot multi-box Detector), R-CNN (Region-based CNN) and R-FCN (Region-based Fully Convolutional Networks) was conducted to measure how fast and accurate they are in identifying objects on the road, such as vehicles, pedestrians ...


Returns On Library Investment: A Study Of The Leading Engineering And Technology Institutes In India, Shivendra Singh, Ramesh Pandita Mr. 2019 All India Institute of Medical Sciences, Patna, India

Returns On Library Investment: A Study Of The Leading Engineering And Technology Institutes In India, Shivendra Singh, Ramesh Pandita Mr.

Library Philosophy and Practice (e-journal)

The study is based on the secondary data compiled by the Ministry of Human Resource & Development, Govt., of India for the period 2012-13, 2013-14 & 2014-15 and was released as the ranking list of Institutes of Engineering and Technology in India for the year 2016. The study aims to assess the Returns on Investment (ROI) of the twenty leading libraries of the Institutes of Engineering and Technology in India in the form of institutional research output. An attempted has also been made to rank the each individual library on the basis of seven different parameters chosen for the study and worked ...


A Sophomore Level Introduction To Engineering Design Course, Norman Muzzy, Michelle L. Soupir, Steven J. Hoff 2019 Iowa State University

A Sophomore Level Introduction To Engineering Design Course, Norman Muzzy, Michelle L. Soupir, Steven J. Hoff

Norman Muzzy

Iowa State University has a sophomore level course that is known as ABE 218. The objectives of this course include learning a structured approach to engineering design, preparing the students for internships, learning the basics of project management, and connecting the theoretical engineering paper designs to physical reality. This informal paper discusses how the course is structured, identifies the lab projects that are part of the course, and discusses some of the results and challenges associated with ABE 218.


Applying What You Have Learned, Gretchen Mosher, Norman Muzzy, Dana Woolley 2019 Iowa State University

Applying What You Have Learned, Gretchen Mosher, Norman Muzzy, Dana Woolley

Norman Muzzy

Last April, a group of over 110 students presented their Capstone projects in the Department of Agricultural and Biosystems Engineering at Iowa State University. The Capstone program serves students in engineering and technology and is a required component of all ABE undergraduates. Capstone programs in engineering and technology are divided into two phases: a first-semester focus on defining the scope of the problem, and an emphasis on solution development and evaluation in the second semester. At the end of the first semester, the teams present their accomplishments at a poster session, where they receive feedback from ABE faculty and industry ...


Global Validation Of Columnar Water Vapor Derived From Eos Modis-Maiac Algorithm Against The Ground-Based Aeronet Observations, Vitor S. Martins, Alexei Lyapustin, Yujie Wang, David M. Giles, Alexander Smirnov, Ilya Slutsker, Sergey Korkin 2019 Iowa State University

Global Validation Of Columnar Water Vapor Derived From Eos Modis-Maiac Algorithm Against The Ground-Based Aeronet Observations, Vitor S. Martins, Alexei Lyapustin, Yujie Wang, David M. Giles, Alexander Smirnov, Ilya Slutsker, Sergey Korkin

Vitor Martins

The water vapor is a relevant greenhouse gas in the Earth's climate system, and satellite products become one of the most effective way to characterize and monitor the columnar water vapor (CWV) content at global scale. Recently, a new product (MCD19) was released as part of MODIS (Moderate Resolution Imaging Spectroradiometer) Collection 6 (C6). This operational product from Multi-Angle Implementation for Atmospheric Correction (MAIAC) algorithm includes a high 1 km resolution CWV retrievals. This study presents the first global validation of MAIAC C6 CWV obtained from MODIS MCD19A2 product. This evaluation was performed using Aerosol Robotic Network (AERONET) observations ...


Validation Of High‐Resolution Maiac Aerosol Product Over South America, Vitor S. Martins, Alexei Lyapustin, Lino A.S. de Carvalho, Claudio C.F. Barbosa, Evlyn M.L.M. Novo 2019 Iowa State University

Validation Of High‐Resolution Maiac Aerosol Product Over South America, Vitor S. Martins, Alexei Lyapustin, Lino A.S. De Carvalho, Claudio C.F. Barbosa, Evlyn M.L.M. Novo

Vitor Martins

Moderate Resolution Imaging Spectroradiometer (MODIS) algorithm that combines time series approach and image processing to derive surface reflectance and atmosphere products, such as aerosol optical depth (AOD) and columnar water vapor (CWV). The quality assessment of MAIAC AOD at 1 km resolution is still lacking across South America. In the present study, critical assessment of MAIAC AOD550 was performed using ground‐truth data from 19 Aerosol Robotic Network (AERONET) sites over South America. Additionally, we validated the MAIAC CWV retrievals using the same AERONET sites. In general, MAIAC AOD Terra/Aqua retrievals show high agreement with ground‐based measurements, with ...


Seasonal And Interannual Assessment Of Cloud Cover And Atmospheric Constituents Across The Amazon (2000–2015): Insights For Remote Sensing And Climate Analysis, Vitor S. Martins, Evlyn M.L.M. Novo, Alexei Lyapustin, Luiz E.O.C. Aragão, Saulo R. Freitas, Claudio C.F. Barbosa 2019 Iowa State University

Seasonal And Interannual Assessment Of Cloud Cover And Atmospheric Constituents Across The Amazon (2000–2015): Insights For Remote Sensing And Climate Analysis, Vitor S. Martins, Evlyn M.L.M. Novo, Alexei Lyapustin, Luiz E.O.C. Aragão, Saulo R. Freitas, Claudio C.F. Barbosa

Vitor Martins

The quantitative assessment of cloud cover and atmospheric constituents improves our ability to exploit the climate feedback into the Amazon basin. In the 21st century, three droughts have already occurred in the Amazonia (e.g. 2005, 2010, 2015), inducing regional changes in the seasonal patterns of atmospheric constituents. In addition to climate, the atmospheric dynamic and attenuation properties are long-term challenges for satellite-based remote sensing of this ecosystem: high cloudiness, abundant water vapor content and biomass burning season. Therefore, while climatology analysis supports the understanding of atmospheric variability and trends, it also offers valuable insights for remote sensing applications. In ...


Observation Of Η-Al41sm5 Reveals Motif-Aware Structural Evolution In Al-Sm Alloys, Zhuo Ye, F. Meng, Feng Zhang, Yang Sun, L. Yang, S. H. Zhou, Ralph E. Napolitano, Mikhail I. Mendelev, Ryan T. Ott, Matthew J. Kramer, Cai-Zhuang Wang, Kai-Ming Ho 2019 Ames Laboratory

Observation Of Η-Al41sm5 Reveals Motif-Aware Structural Evolution In Al-Sm Alloys, Zhuo Ye, F. Meng, Feng Zhang, Yang Sun, L. Yang, S. H. Zhou, Ralph E. Napolitano, Mikhail I. Mendelev, Ryan T. Ott, Matthew J. Kramer, Cai-Zhuang Wang, Kai-Ming Ho

Ralph E. Napolitano

Using an effective genetic algorithm, we uncover the structure of a metastable Al41Sm5 phase that supplements its family sharing similar short-range orders. The phase evolves upon heating an amorphous Al-9.7 at.% Sm ribbon, produced by melt-spinning. The dynamical phase selection is discussed with respect to the structural connections between the short-range packing motifs in the amorphous precursor and those observed in the selected phases. The phase elucidated here is one of several newly discovered large-unit-cell phases found to form during devitrification from the glass in this binary system, further illustrating the power and efficiency of our approach, the important ...


Digital Commons powered by bepress