Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Engineering
Selective Actuation And Sensing Of Antisymmetric Lamb Wave Mode Using D15 Piezoelectric Transducers, Parry Carrison
Selective Actuation And Sensing Of Antisymmetric Lamb Wave Mode Using D15 Piezoelectric Transducers, Parry Carrison
Theses and Dissertations
Undetected damage in aircraft can lead to catastrophic failures and loss of life. Automated embedded damage detection systems can reduce manhours and downtime due to inspection. Ultrasonic inspection has become one of the most capable methods for thin plate-like structures, such as aircraft spars, stiffeners, and skins. Piezoelectric transducers can inspect structures by generating ultrasonic Lamb waves and sensing how they propagate. Many Lamb wave modes exist at a given frequency, which makes signal interpretation challenging. Selective actuation of a single mode simplifies the signal analysis. The A0 mode has the shortest wavelength, which increases sensitivity to small defects, and …
Impact Load Identification Using Optimal Sensor Placement And Model Reduction, Bella Jackson Chembakassery
Impact Load Identification Using Optimal Sensor Placement And Model Reduction, Bella Jackson Chembakassery
Theses and Dissertations
Any structure which is used in service can be subjected to different kinds of loads such as static, dynamic, moving or impact loads. It is very much necessary such structures are reliable and robust enough to be used for service. Hence accurately estimating the load acting on the structure is very important. In case of impact loading, it is very difficult to estimate the load because it acts for a short period of time. For such loading, the structural response of the system can be used as a medium to estimate the applied load. The structural response used could be …
Investigation Of A Novel Turbulence Model And Using Leading-Edge Slots For Improving The Aerodynamic Performance Of Airfoils And Wind Turbines, Saman Beyhaghi
Investigation Of A Novel Turbulence Model And Using Leading-Edge Slots For Improving The Aerodynamic Performance Of Airfoils And Wind Turbines, Saman Beyhaghi
Theses and Dissertations
Because of the problems associated with increase of greenhouse gases, as well as the limited supplies of fossil fuels, the transition to alternate, clean, renewable sources of energy is inevitable. Renewable sources of energy can be used to decrease our need for fossil fuels, thus reducing impact to humans, other species and their habitats. The wind is one of the cleanest forms of energy, and it can be an excellent candidate for producing electrical energy in a more sustainable manner. Vertical- and Horizontal-Axis Wind Turbines (VAWT and HAWT) are two common devices used for harvesting electrical energy from the wind. …
Numerical And Experimental Study Of Liquid Breakup Process In Solid Rocket Motor Nozzle, Yi-Hsin Yen
Numerical And Experimental Study Of Liquid Breakup Process In Solid Rocket Motor Nozzle, Yi-Hsin Yen
Theses and Dissertations
Rocket propulsion is an important travel method for space exploration and national defense, rockets needs to be able to withstand wide range of operation environment and also stable and precise enough to carry sophisticated payload into orbit, those engineering requirement makes rocket becomes one of the state of the art industry. The rocket family have been classified into two major group of liquid and solid rocket based on the fuel phase of liquid or solid state. The solid rocket has the advantages of simple working mechanism, less maintenance and preparing procedure and higher storage safety, those characters of solid rocket …
Computational And Experimental Study On Innovative Horizontal-Axis Wind Turbine Blade Designs, Abdulrahman A. Alsultan
Computational And Experimental Study On Innovative Horizontal-Axis Wind Turbine Blade Designs, Abdulrahman A. Alsultan
Theses and Dissertations
This study was made to explore three novel blade geometries with intent to increase power production of a horizontal axes, three blade arrangement wind turbine. This was done by designing the blades using computer aided design (CAD) modeling software, followed by a rigorous testing phase, utilizing a computational fluid dynamics software (CFD). The blades then went into a cycle of iterative design to achieve the best parameters that will positively impact the overall power generation efficiency. These steps were followed by printing the blades utilizing 3D Printing technology, testing them for the power generation, and finally, tabulating these findings to …
Aerodynamic Analysis And Drag Coefficient Evaluation Of Time-Trial Bicycle Riders, Peter Nicholas Doval
Aerodynamic Analysis And Drag Coefficient Evaluation Of Time-Trial Bicycle Riders, Peter Nicholas Doval
Theses and Dissertations
Evaluation of drag coefficient often requires wind tunnel experiments and can be prohibitively expensive if not impossible for large objects or systems. Computational Fluid Dynamics (CFD) aerodynamic analysis offers an alternative approach and can be used as a very effective design tool in many industries: automotive, aerospace, marine, etc. The main objective of this research is to investigate feasibility of using non-contact digitizers for developing finite element models of large objects for subsequent CFD analysis. The developed methodology is applied to investigation of time-trial bicycle rider efficiency. Companies competing in this class of racing spend millions trying to optimize bicycle …