Mechanical Engineering Commons^™

Direct Simulations Of Cells Motions And Deformations In Flow, Quan Jin

Dissertations

Direct numerical simulations (DNS) are used to study the motions and deformations of blood cells, especially leukocytes, in pressure driven flows in parallel plate channels with both smooth and uneven walls under adhesion force between the leukocytes and the channel wall.

Leukocytes are represented by two composite fluid models. The first model is the compound-drop model in which the cytoplasm and the nucleus are modeled as fluids, and the second one is the drop-rigid-particle model in which the cytoplasm is modeled as a fluid and the nucleus as a rigid particle. The adhesion force is computed using two adhesion force …

Synthesis And Analysis Of Reactive Nanocomposites Prepared By Arrested Reactive Milling, Swati M. Umbrajkar

Dissertations

Different types of reactive nanocomposites have been synthesized by Arrested Reactive Milling (ARM). The technical approach was to increase the interface area available for heterogeneous reaction between solid fuel and oxidizer components. Using aluminum as the main fuel and different metal oxides as oxidizers, highly energetic reactive nanocomposites with different degrees of structural refinement were synthesized. Specifically, stoichiometric Al-MoO₃, Al-CuO, and Al-NaNO₃ material systems were studied in detail.

The correlation of heterogeneous exothermic reactions occurring in the nanocomposite powders upon their heating at low rates and ignition events observed for the same powders heated rapidly was of …

Nanoparticle Formation And Coating Using Supercritical Fluids, Abhijit Aniruddha Gokhale

Dissertations

Jet breakup phenomenon and nanoparticle formation

The focus of this dissertation is to study the SAS process to manufacture nanoparticles with minimum agglomeration, controlled size and size distribution. Solution jet breakup and solvent evaporation into supercritical fluid (SC CO₂) is studied using high speed charged coupled device (CCD) camera facilitated with double shot particle image veloimetry (PIV) laser and a high pressure view cell. Particles formation using SAS is studied. Polyvinylpyrrolidone (PVP) particles are formed using micron size capillary nozzles and combination of thermodynamically good and poor solvents in order to achieve nano-sized particles with reduced agglomeration and …

Flow Characteristics And Phase Interactions Of Evaporating Sprays In Gas-Solid Suspensions, Muhammad Mushahid Rafique Qureshi

Dissertations

Evaporating spray jets have a wide range of applications in many industrial processes such as fluidized catalytic cracking of crude oil in petroleum refinery, coal gasification, fluidized coking to make synthetic crude oil, and condensed mode gas polymerization. The rapid evaporation of spray jets significantly affects the gas-solids mixing, solids concentration, gas/solids temperature and gas/solids velocity acceleration. The complex interactions mechanism of phase change, three phase interaction, heat and mass transfer of gas, solids and evaporating droplets dominate the process efficiency and product quality. In such three-phase flows, the phase transport characteristics are influenced by both droplet-gas interaction and droplet-solid …

Investigation Of Formation And Applications Of High-Speed Liquid Projectiles, Oleg Petrenko

Dissertations

The work comprises experimental and numerical studies of generation and application of high-speed liquid projectiles. Numerical models were created for a projectile formation by two kinds of launchers, water extruder and water cannon. In the water extruder the kinetic energy of a fast moving piston is transferred to the water load and extrudes the load at a high speed. By contrast in the water cannon the water load itself accumulates the kinetic energy from the expanding combustion gasses. Then, in the course of water motion through the converging nozzle the energy is redistributed between head and tail of the projectile. …

Numerical Analysis Of The Operation Of A Water Cannon, Teymuraz G. Bitadze

Theses

This study was designed to investigate the operational process of a launcher for generation of high speed water projectiles, and it involved the optimization of the geometry of a launcher body. The objective of the optimization of the internal geometry was to increase the effective momentum of the projectile while the optimization of the external geometry resulted in the reduction of the mass of the launcher.

In the course of the optimization of the internal geometry the exit velocity variation was determined, and used to compute an effective projectile momentum, which actually affects a workpiece. In this research, it was …

Burmester Curve And Numerical Motion Generation Of Grashof Mechanisms With Perimeter And Transmission Angle Optimization In Mathcad, Peter J. Martin

Theses

An infinite number of planar four-bar mechanism solutions exist for a series of prescribed rigid-body positions. Given a set of Burmester curves or numerically-generated fixed and moving pivot curves, sorting through the limitless number of possible mechanism solutions to find one that ensures full link rotatibility, satisfies compactness criteria and produces feasible transmission angles can be a daunting task. In this work, two algorithms are developed and presented by which the user can select optimum planar four-bar motion generators (optimum with respect to Grashof criteria, mechanism perimeter criteria and transmission angle criteria) from a set of all mechanism solutions produced …