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Full-Text Articles in Engineering
Methods For Identifying Acoustic Emissions From The Front Face Of A Small Piezoelectric Blower, Brad K. Solomon
Methods For Identifying Acoustic Emissions From The Front Face Of A Small Piezoelectric Blower, Brad K. Solomon
Theses and Dissertations
This thesis focuses on identifying acoustic noise generating components in piezoelectric blowers through transverse velocity measurements and the development of a numerical fluid model. Piezoelectric ceramics have proven useful for many industries and areas of research involving: high precision actuators, noise control, ultrasonic devices, and many other areas. As of late, a unique adaptation of piezoelectric ceramics is surfacing in the area of pumping and cooling. Air pumps that use these ceramics replace the traditional electric motor, resulting in lower power consumption, less moving parts, constant pressure gradients, lower overall weight, and a low profile. The current drawback of this …
Evaluation Of Turbulence Variable Distributions For Incompressible Fully Rough Pipe Flows, Emilie B. Fowler
Evaluation Of Turbulence Variable Distributions For Incompressible Fully Rough Pipe Flows, Emilie B. Fowler
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The specific turbulent kinetic energy, root-mean-square fluctuating vorticity, and mean-vortexwavelength distributions are presented for fully rough pipe flow. The distributions of these turbulence variables are obtained from a proposed turbulence model. Many of the turbulence models commonly used for computational fluid dynamics are based on an analogy between molecular and turbulent transport. However, traditional k-ε and k-ω models fail to exhibit proper dependence on the molecular viscosity. Based on a rigorous application of the Boussinesq’s hypothesis, Phillips proposed a vorticity-based transport equation for the turbulent kinetic energy. The foundation for this vorticity-based transport equation is presented. In future development of …
Large-Eddy Simulation Of Axially-Rotating, Turbulent Pipe And Particle-Laden Swirling Jet Flows, Nicolas D. Castro
Large-Eddy Simulation Of Axially-Rotating, Turbulent Pipe And Particle-Laden Swirling Jet Flows, Nicolas D. Castro
Mechanical & Aerospace Engineering Theses & Dissertations
The flows of fully-developed turbulent rotating pipe and particle-laden swirling jet emitted from the pipe into open quiescent atmosphere are investigated numerically using Large-Eddy Simulation (LES). Simulations are performed at various rotation rates and Reynolds numbers, based on bulk velocity and pipe diameter, of 5.3x103, 12x103, and 24x103, respectively. Time-averaged LES results are compared with experimental and simulation data from previous studies. Pipe flow results confirm observations in previous studies, such as the deformation of the turbulent mean axial velocity profile towards the laminar Poiseuille-profile, with increased rotation. The Reynolds stress anisotropy tensor shows a redistribution due to pipe rotation. …
Numerical Simulation Of Buoyancy-Driven Turbulent Ventilation In Attic Space Under Winter Conditions, Shimin Wang, Zhigang Shen, Linxia Gu
Numerical Simulation Of Buoyancy-Driven Turbulent Ventilation In Attic Space Under Winter Conditions, Shimin Wang, Zhigang Shen, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
Attic design and construction have significant impacts on residential buildings’ energy performance. In order to understand how passive ventilation rates affect ridge-vent attic’s performance, a two-dimensional steady-state finite volume model is employed to simulate the buoyancy-driven turbulent ventilation and heat transfer in a triangular attic space of a gable-roof residential building under winter conditions. The modeled attic has a pitch of 5/12 and a passive ventilation system, consisting of continuous ridge and soffit vents. The v2f model is used to analyze the turbulent air flow and natural convection heat transfer inside the attic. The effects of ambient air temperature, vent …