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Aerodynamics and Fluid Mechanics Commons™

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2016

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Articles 31 - 40 of 40

Full-Text Articles in Aerodynamics and Fluid Mechanics

Flame-Turbulence Interaction For Deflagration To Detonation, Jessica Chambers Jan 2016

Flame-Turbulence Interaction For Deflagration To Detonation, Jessica Chambers

Honors Undergraduate Theses

Detonation is a high energetic mode of pressure gain combustion that exploits total pressure rise to augment high flow momentum and thermodynamic cycle efficiencies. Detonation is initiated through the Deflagration-to-Detonation Transition (DDT). This process occurs when a deflagrated flame is accelerated through turbulence induction, producing shock-flame interactions that generate violent explosions and a supersonic detonation wave. There is a broad desire to unravel the physical mechanisms of turbulence induced DDT. For the implementation of efficient detonation methods in propulsion and energy applications, it is crucial to understand optimum turbulence conditions for detonation initiation. The study examines the role of turbulence-flame …

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Effects Of Altitude On Monarch Butterfly Aerodynamics, Brittany Greene Jan 2016

Effects Of Altitude On Monarch Butterfly Aerodynamics, Brittany Greene

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

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The Effects Of Rarefaction And Thermal Non-Equilibrium On A Blunt Body And A Bicone In Hypersonic Flow And Their Shape Optimization For Reducing Both Drag And Heat Transfer, Samuel Gardner Jan 2016

The Effects Of Rarefaction And Thermal Non-Equilibrium On A Blunt Body And A Bicone In Hypersonic Flow And Their Shape Optimization For Reducing Both Drag And Heat Transfer, Samuel Gardner

McKelvey School of Engineering Graduate Student Theses & Dissertations

Design of space vehicles pose many challenging problems due to their hypersonic speeds since they need to travel through different flow regimes due to changes in the density of the atmosphere with altitude. Some of the key characteristics associated with hypersonic flow are extremely high temperatures and heat transfer to the wall of the spacecraft. At these temperatures, the assumption of thermal equilibrium is no longer valid and the effect of rotational non-equilibrium must be included in the modeling of diatomic gas flow. This thesis employs the Navier-Stokes equations, which are modified to include a rotational non-equilibrium relaxation model to …

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An Experimental Investigation Of Heat Transfer For Arrays Of Impingement Jets Onto The Featured Surfaces With Cylindrical And Elliptical Raised Surfaces, Marc A. Medina Jan 2016

An Experimental Investigation Of Heat Transfer For Arrays Of Impingement Jets Onto The Featured Surfaces With Cylindrical And Elliptical Raised Surfaces, Marc A. Medina

Honors Undergraduate Theses

This study focuses on multi-jet impingement for gas turbine geometries in which the objective is to understand the influence of the roughness elements on a target surface to the heat transfer. Current work has proven that implementing roughness elements for multi-jet impingement target surfaces has increased heat transfer ranging anywhere from 10-30%. This study has chosen to investigate three different roughness elements, elliptical in cross-section, to compare to smooth surface geometries for multi-jet impingement. An experimental was taken for this study to extend the current knowledge of multi-jet impingement geometries and to further understand the heat transfer performance. A temperature …

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Comparisons Of Ablator Experimental Performance To Response Modeling And Effects Of Water Phase Transition In Porous Tps Materials, David L. Smith Jan 2016

Comparisons Of Ablator Experimental Performance To Response Modeling And Effects Of Water Phase Transition In Porous Tps Materials, David L. Smith

Theses and Dissertations--Mechanical and Aerospace Engineering

The Mars Science Laboratory Entry Descent and Landing Instrumentation (MEDLI) project performed extensive arc jet tests for development, qualification, and calibration of instrumented heat shield plugs. These plugs each contained several thermocouples for recording near-surface and in-depth temperature response of the Phenolic Impregnated Carbon Ablator (PICA) heat shield. The arc jet test results are entered into a comprehensive database so that broad trends across the test series can be compared. One method of analysis is to compare with ablator material response calculations and solve the in-depth heat conduction equations. Using the near-surface thermocouple measurements as a boundary condition in numerical …

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High Temperature Shock Tube Ignition Studies Of Co2 Diluted Mixtures, Owen Pryor Jan 2016

High Temperature Shock Tube Ignition Studies Of Co2 Diluted Mixtures, Owen Pryor

Electronic Theses and Dissertations

Energy demand is expected to grow by 20% over the next 10 years. In order to account for this increase in energy consumption new and novel combustion techniques are required to mitigate the effects of pollution and fossil fuel dependency. Oxy-fuel combustion in supercritical carbon dioxide (sCO2) cycles can increase plant efficiencies up to 52% and reduce pollutants such as NOX and CO2 by 99%. Supercritical engine cycles have demonstrated electricity costs of $121/MWh, which is competitive in comparison to conventional coal ($95.60/MWh) and natural gas power plants ($128.4/MWe). This increase in efficiency is mainly driven by the near-liquid density …

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First-Year Project Experience In Aerospace: Apogee Determination Of Model Rockets With Explicit Consideration Of Drag Effect, Hüseyin Sarper, Drew Landman, Linda Vahala Jan 2016

First-Year Project Experience In Aerospace: Apogee Determination Of Model Rockets With Explicit Consideration Of Drag Effect, Hüseyin Sarper, Drew Landman, Linda Vahala

Electrical & Computer Engineering Faculty Publications

This paper describes a student team project using model rockets and engines to learn engineering solution methods for determining the apogee of model rocket when the drag effect is considered explicitly instead of estimating its effect later. Model rocketry is a powerful tool for instructors who wish to incorporate science, engineering, and mathematics into a fun, engaging, and challenging activity for the students. The apogee can be determined using a number of distinct methods: trigonometry, onboard altimeters, analytical calculations, and simulation. This paper emphasizes numerical analytical solution using spreadsheet programming instead of a full analytical solution that requires higher mathematics. …

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Rocket Fin Test Fixture Development & Exploration Of Rotation Inducing Fin Design, Ryan A. Saylor Mr., David J. Royak Mr., Jacob P. Byron Mr. Jan 2016

Rocket Fin Test Fixture Development & Exploration Of Rotation Inducing Fin Design, Ryan A. Saylor Mr., David J. Royak Mr., Jacob P. Byron Mr.

Williams Honors College, Honors Research Projects

The purpose of this senior project was to develop a method of applying rotation inducing rocket fin concepts to rockets for the benefit of the University of Akron Akronauts; the student led rocket design team. The project was performed independently of the team’s current efforts as a research and development endeavor for future team projects. Main project goals were divided into three parts: design a fin test fixture for verification testing in the University’s wind tunnel, develop a parameter-driven software model that could be used to generate design options with theoretical performance data as an output, and run fluid dynamics …

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Quantitative Assessment Of Secondary Flows Of Single-Phase Fluid Through Pipe Bends, Z. Kaldy, O. Ayala Jan 2016

Quantitative Assessment Of Secondary Flows Of Single-Phase Fluid Through Pipe Bends, Z. Kaldy, O. Ayala

Engineering Technology Faculty Publications

Single-phase fluid flow was simulated passing through various three dimensional pipe elbows. The simulations varied by Reynolds number, curvature ratios, and sweep angles and were all conducted using the k-e model available in COMSOL Multiphysics 5.1. The intent of this research was to qualitatively assess the flow characteristics under several different conditions. Many similarities were seen especially when comparing curvature ratios, the vorticity location for the turbulent cases show near identical behavior at the elbow midsection. One of the variables quantified in this paper is the maximum secondary velocity module which shows increasing values until the midsection of the elbow.

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Secondary Flow Of Liquid-Liquid Two-Phase Fluids In A Pipe Bend, M. Ayala, P. Santos, G. Hamester, O. Ayala Jan 2016

Secondary Flow Of Liquid-Liquid Two-Phase Fluids In A Pipe Bend, M. Ayala, P. Santos, G. Hamester, O. Ayala

Engineering Technology Faculty Publications

A simulated study of oil and water in 90 degree bend was carried on COMSOL 5.1 to characterize flow pattern and analyze the secondary flow. The Euler-Euler k-e Reynolds Averaged Navier-Stokes model was used to represent the fluid motion. Changes in the Reynolds number, curvature ratio and direction of gravity were made to evaluate the effects in the intensity of the secondary flow. In the end, it was possible to see that the bend direction does not affect the formation of secondary flow for Reynolds above 100,000. It appears that the fluid behavior on the pipe bend is strongly related …

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