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Full-Text Articles in Engineering Science and Materials

A Nonequilibrium Finite-Rate Carbon Ablation Model For Radiating Earth Re-Entry Flows, Christopher R. Alba Sep 2015

A Nonequilibrium Finite-Rate Carbon Ablation Model For Radiating Earth Re-Entry Flows, Christopher R. Alba

Theses and Dissertations

Vehicles entering planetary atmospheres at high speed require an ablative heat shield in order to withstand the high thermal energy flux to the body. The interaction between the ablative products and the flow field is not well characterized. Numerical simulations were conducted to investigate the influence of carbon ablation on shock layer radiation. Data collected from experiments performed in the X-2 expansion tunnel at the University of Queensland was used to compare to the simulations. The model was a short half-cylinder made of isomolded graphite and was tested in 8.6 km/s Earth entry flow. The model surface was ...


Effect Of Time Delay Between Etching And Adhesive Bonding (“Outlife” Time) On Lap-Shear Strength Of Aluminum Alloys Using Environmentally-Friendly P2 Etch, Josh Barkhimer, Matthew Erich, Gokul Nair Jun 2015

Effect Of Time Delay Between Etching And Adhesive Bonding (“Outlife” Time) On Lap-Shear Strength Of Aluminum Alloys Using Environmentally-Friendly P2 Etch, Josh Barkhimer, Matthew Erich, Gokul Nair

Materials Engineering

Raytheon Company currently uses a Forest Products Laboratory (FPL) paste etchant for preparing aluminum surfaces for adhesive bonding, and FPL is a source of hazardous hexavalent chromium. The goal of this study was to evaluate a less-toxic P2 paste etchant as a possible replacement. Coupons of 2024-T3, 6061-T6, and 7075-T6 grades of aluminum alloy were solvent-degreased, abrasively cleaned, and etched at room temperature using P2 paste following a strict protocol adopted from Raytheon. Coupons were then left exposed to air for assigned time intervals (or “outlife” times) of 0, 1, 4, 8, 16, and 63 or 72 hours. The aluminum ...


Suborbital Spaceflight: A Student Team’S Plan To Send A Rocket To Space, Bryce Chanes, William Carpenter, Julio Benavides, Matthew Haslam, Brenda Haven Jan 2015

Suborbital Spaceflight: A Student Team’S Plan To Send A Rocket To Space, Bryce Chanes, William Carpenter, Julio Benavides, Matthew Haslam, Brenda Haven

Aviation / Aeronautics / Aerospace International Research Conference

The Eagle Space Flight Team was created with the goal of becoming the first undergraduate team to design, build, and launch a rocket capable of suborbital spaceflight. In order to achieve this goal, the team will have to design a rocket capable of atmospheric flight at speeds over Mach 5 and launch it on one of the largest amateur rocket motors ever made. Over the next three years, the team will progress towards accomplishing this feat through a series of incremental test flights. Before the space flight, the team will build three sub-scale rockets designed to reach altitudes of 30 ...


Transient Thermoelectric Supercooling: Isosceles Current Pulses From A Response Surface Perspective And The Performance Effects Of Pulse Cooling A Heat Generating Mass, Alfred Piggott Jan 2015

Transient Thermoelectric Supercooling: Isosceles Current Pulses From A Response Surface Perspective And The Performance Effects Of Pulse Cooling A Heat Generating Mass, Alfred Piggott

Dissertations, Master's Theses and Master's Reports

With increased public interest in protecting the environment, scientists and engineers aim to improve energy conversion efficiency. Thermoelectrics offer many advantages as thermal management technology. When compared to vapor compression refrigeration, above approximately 200 to 600 watts, cost in dollars per watt as well as COP are not advantageous for thermoelectrics. The goal of this work was to determine if optimized pulse supercooling operation could improve cooling capacity or efficiency of a thermoelectric device. The basis of this research is a thermal-electrical analogy based modeling study using SPICE. Two models were developed. The first model, a standalone thermocouple with no ...


Magnus Effect In Duct Flow, Jesse S. Batko, Cameron W. Clarke, Kenneth W. Smith Jr. Jan 2015

Magnus Effect In Duct Flow, Jesse S. Batko, Cameron W. Clarke, Kenneth W. Smith Jr.

Williams Honors College, Honors Research Projects

The following research paper details the preliminary research carried out by this team. The project was originally conceived to determine if Magnus Lift could be utilized in an unconventional way to assist rockets during takeoff. Several conceptual designs were proposed, but the idea was scrapped when it became apparent that the team would not be able to generate the desired lift without inducing significant amounts of drag and additional weight on a rocket. Instead, the team focused on researching an interesting topic that hasn’t been previously explored: Magnus lift on a cylinder within a duct.

An experimental procedure that ...


Magnus Effect In Duct Flow, Cameron W. Clarke, Jesse S. Batko, Kenneth W. Smith Jr. Jan 2015

Magnus Effect In Duct Flow, Cameron W. Clarke, Jesse S. Batko, Kenneth W. Smith Jr.

Williams Honors College, Honors Research Projects

The following research paper details the preliminary research carried out by this team. The project was originally conceived to determine if Magnus Lift could be utilized in an unconventional way to assist rockets during takeoff. Several conceptual designs were proposed, but the idea was scrapped when it became apparent that the team would not be able to generate the desired lift without inducing significant amounts of drag and additional weight on a rocket. Instead, the team focused on researching an interesting topic that hasn’t been previously explored: Magnus lift on a cylinder within a duct. An experimental procedure that ...


High Temperature Flow Solver For Aerothermodynamics Problems, Huaibao Zhang Jan 2015

High Temperature Flow Solver For Aerothermodynamics Problems, Huaibao Zhang

Theses and Dissertations--Mechanical Engineering

A weakly ionized hypersonic flow solver for the simulation of reentry flow is firstly developed at the University of Kentucky. This code is the fluid dynamics module of known as Kentucky Aerothermodynamics and Thermal Response System (KATS). The solver uses a second-order finite volume approach to solve the laminar Navier– Stokes equations, species mass conservation and energy balance equations for flow in chemical and thermal non-equilibrium state, and a fully implicit first-order backward Euler method for the time integration. The hypersonic flow solver is then extended to account for very low Mach number flow using the preconditioning and switch of ...


Acoustic Emission Characteristics Of Damage Accumulation In Kevlar® 49 Composites, Eduardo Andrade Jan 2015

Acoustic Emission Characteristics Of Damage Accumulation In Kevlar® 49 Composites, Eduardo Andrade

Open Access Theses & Dissertations

Acoustic emission (AE) data attained during tensile testing of epoxy impregnated Kevlar® 49 (K/Ep) composite strands were reduced and analyzed to monitor progressive damage accumulation during the approach to tensile failure. The K/Ep material tested in this study was chosen due to its similarity to the material-of-construction used in composite overwrapped pressure vessels (COPVs) used on the NASA Space Shuttle Orbiter. Insight into the progressive microstructural degradation of K/Ep strands was gained by monitoring AE event rate and energy. Source location based on energy attenuation and arrival time data was used to differentiate between significant AE attributable ...


Aero-Thermal Characterization Of Silicon Carbide Flexible Tps Using A 30kw Icp Torch, Walten Owens Jan 2015

Aero-Thermal Characterization Of Silicon Carbide Flexible Tps Using A 30kw Icp Torch, Walten Owens

Graduate College Dissertations and Theses

Flexible thermal protection systems are of interest due to their necessity for the success of future atmospheric entry vehicles. Current non-ablative flexible designs incorporate a two-dimensional woven fabric on the leading surface of the vehicle. The focus of this research investigation was to characterize the aerothermal performance of silicon carbide fabric using the 30 kW Inductively Coupled Plasma Torch located at the University of Vermont. Experimental results have shown that SiC fabric test coupons achieving surface temperatures between 1000°C and 1500°C formed an amorphous silicon dioxide layer within seconds after insertion into air plasmas. The transient morphological changes ...