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Full-Text Articles in Engineering
Unsteady Flow Behaviors Generated By Three-Dimensional Lattice Geometries As Measured By Laser Doppler Velocimetry, Yi Qiao
Doctoral Dissertations
"The relation between flow stream turbulence and heat transfer has been known for a long time, that the heat transfer rate is increased if the turbulence or fluctuation level of the flow increases. Open cell foams and compact heat exchangers are two of the most common models applied for heat transfer augmentation. However, the small ligaments of open cell foams limit the heat conducted and smooth passages in compact heat exchangers cannot cause flow unsteadiness. Accordingly, new geometric models are needed to improve the heat transfer enhancement. Three-dimensional (3D) lattice geometries with a range of features and sizes can be …
A Primal Treatise Of Constant-Force Compliant Segment And Mechanism Design With Applications, Vamsi Lodagala
A Primal Treatise Of Constant-Force Compliant Segment And Mechanism Design With Applications, Vamsi Lodagala
Doctoral Dissertations
"The evolution of compliant mechanisms propelled the development of constant-force mechanisms (CFMs) for various applications because of their unique characteristics. Many research endeavors have presented different techniques that often involve some optimization to design the CFMs. However, the mechanics of the generation of constant force at the elemental level is not well understood. This research effort theorizes and validates that simple, compliant segment with different boundary conditions, subjected to axial loading, produce near-constant force without the need for design optimization. Analytical models are developed based on the pseudo-rigid-body model (PRBM) concept to predict their force-displacement behavior, and to establish that …
Characterization And Improvement Of Powder Properties Through Plasma Spheroidization For Use In The Laser Powder Bed Fusion Process, M. Hossein Sehhat
Characterization And Improvement Of Powder Properties Through Plasma Spheroidization For Use In The Laser Powder Bed Fusion Process, M. Hossein Sehhat
Doctoral Dissertations
"This research was conducted to characterize the powder properties using different characterization techniques to enhance the powder behavior in the Laser Powder Bed Fusion (LPBF) process. One of the shortcomings of LPBF process is the high cost of gas-atomized powder feedstock. To overcome this downside, the cheaper water-atomized powder was characterized and used in LPBF process, and its performance was compared with those of gas-atomized powder. Also, the plasma spheroidization process was used to improve the powder characteristics; if the spheroidized powder could function as well as the virgin powder, plasma spheroidization process could be applied to the used powders …