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Mechanical Engineering Commons™

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Aerospace Engineering

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Purdue University

2015

Articles 1 - 10 of 10

Full-Text Articles in Mechanical Engineering

Assessment Of Critical Technologies For Gas Turbine Engines Using Numerical Tools, Vinicius Pessoa Mapelli, Guillermo Paniagua, Jorge Sousa Aug 2015

Assessment Of Critical Technologies For Gas Turbine Engines Using Numerical Tools, Vinicius Pessoa Mapelli, Guillermo Paniagua, Jorge Sousa

The Summer Undergraduate Research Fellowship (SURF) Symposium

In 2014 gas turbine engine has reached a market value of 82.5 billion dollars, of which 59.5% are related to aircraft propulsion. The continuous market expansion attracts more and more the interest of researchers and industries towards the development of accurate numerical techniques to model thermodynamically the entire engine. This practice allows a performance and optimization analysis before the actual experimental testing, reducing the time and required investment in the design of a new engine. In this paper, a recently developed open source numerical tool named “Toolbox for the Modeling and Analysis of Thermodynamic Systems” (T-MATS) is used to assess …

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Altered Combustion Characteristics Of Aluminum Fuels Through Low-Level Fluoropolymer Inclusions With And Without In Situ Nanoaluminum., Courtney K. Murphy, Brandon Terry, Steven F. Son Aug 2015

Altered Combustion Characteristics Of Aluminum Fuels Through Low-Level Fluoropolymer Inclusions With And Without In Situ Nanoaluminum., Courtney K. Murphy, Brandon Terry, Steven F. Son

The Summer Undergraduate Research Fellowship (SURF) Symposium

Aluminum inclusions have been widely used to increase the specific impulse of solid rocket propellant. However, issues arise with the addition of aluminum in the form of agglomeration, which can cause kinetic and thermal losses (i.e., two-phase flow losses) through the nozzle, which can reduce motor performance by as much as 10%. Reduction of agglomerate size may reduce the effect of two-phase flow losses. Polytetrafluoroethylene (PTFE or TeflonTM) inclusions into aluminum via mechanical activation (MA, milling) have been shown to produce a smaller coarse agglomerate size due to microexplosion of the composite particles at the propellant surface. Perflouroalkoxy …

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High Pressure Combustion And Supersonic Jet Ignition For H2/Air, Michael G. Woodworth, Sayan Biswas, Li Qiao Aug 2015

High Pressure Combustion And Supersonic Jet Ignition For H2/Air, Michael G. Woodworth, Sayan Biswas, Li Qiao

The Summer Undergraduate Research Fellowship (SURF) Symposium

There are many incentives to increase the fuel efficiency of combustion processes. This paper looks at two available options to achieve this goal. The former aims to develop an experimental method that can analyze combustion at extremely high pressures to improve the understanding of high pressure H2/air combustion. Experimental data has been lacking a suitable combustion diagnostic to visualize high pressure combustion processes, making it difficult to improve the process. Improvement of x-ray diffraction tomography in a windowless combustor makes it possible to see flame propagation at high pressure. The procedure and chamber are still in the design phase, yet …

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Hot Surface Ignition, Yerbatyr Tursyn, Vikrant Goyal, Alicia Benhidjeb-Carayon, Richard Simmons, Scott Meyer, Jay P. Gore Aug 2015

Hot Surface Ignition, Yerbatyr Tursyn, Vikrant Goyal, Alicia Benhidjeb-Carayon, Richard Simmons, Scott Meyer, Jay P. Gore

The Summer Undergraduate Research Fellowship (SURF) Symposium

Undesirable hot surface ignition of flammable liquids is one of the hazards in ground and air transportation vehicles, which primarily occurs in the engine compartment. In order to evaluate the safety and sustainability of candidate replacement fuels with respect to hot surface ignition, a baseline low lead fuel (Avgas 100 LL) and four experimental unleaded aviation fuels recommended for reciprocating aviation engines were considered. In addition, hot surface ignition properties of the gas turbine fuels Jet-A, JP-8, and JP-5 were measured. A test apparatus capable of providing reproducible data was designed and fabricated to experimentally investigate the hot surface ignition …

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Entropy Minimization Design Approach Of Supersonic Internal Passages, Jorge Sousa, Guillermo Paniagua Aug 2015

Entropy Minimization Design Approach Of Supersonic Internal Passages, Jorge Sousa, Guillermo Paniagua

School of Aeronautics and Astronautics Faculty Publications

Fluid machinery operating in the supersonic regime unveil avenues towards more compact technology. However, internal supersonic flows are associated with high aerodynamic and thermal penalties, which usually prevent their practical implementation. Indeed, both shock losses and the limited operational range represent particular challenges to aerodynamic designers that should be taken into account at the initial phase of the design process. This paper presents a design methodology for supersonic passages based on direct evaluations of the velocity field using the method of characteristics and computation of entropy generation across shock waves. This meshless function evaluation tool is then coupled to an …

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An Experimental Study On The Effects Of Blade Row Interactions On Aerodynamic Loss Mechanisms In A Multistage Compressor, Natalie Rochelle Smith Apr 2015

An Experimental Study On The Effects Of Blade Row Interactions On Aerodynamic Loss Mechanisms In A Multistage Compressor, Natalie Rochelle Smith

Open Access Dissertations

While the gas turbine engine has existed for nearly 80 years, much of the complex aerodynamics which governs compressor performance is still not well understood. The unsteady flow field consists of periodic blade row interactions from the wakes and potential fields of each blade and vane. Vane clocking is the relative circumferential indexing of adjacent vane rows with the same vane count, and it is one method to change blade row interactions. Though the potential of performance benefits with vane clocking is known, the driving flow physics have yet to be identified. ^ This research examines the effects of blade …

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Real-Time Rss-Based Indoor Navigation For Autonomous Uav Flight, Sangjun Lee Apr 2015

Real-Time Rss-Based Indoor Navigation For Autonomous Uav Flight, Sangjun Lee

Open Access Theses

Navigation for the autonomous flight of Unmanned Aerial Vehicles (UAVs) in an indoor space has attracted much attention recently. One of the main goals of an indoor navigation system is developing an alternative method to obtain position information that can replace or complement the global positioning system. While much research has focused on vision-based indoor navigation systems, this paper aims to develop a Received Signal Strength (RSS)-based navigation system, which is a more cost effective alternative. Then, the position and attitude of a UAV can be computed by the fusion of RSS measurements and measurements from the onboard inertial measurement …

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Asymptotic Modelling Of A Thermopiezoelastic Anisotropic Smart Plate, Yufei Long Apr 2015

Asymptotic Modelling Of A Thermopiezoelastic Anisotropic Smart Plate, Yufei Long

Open Access Theses

Motivated by the requirement of modelling for space flexible reflectors as well as other applications of plate structures in engineering, a general anisotropic laminated thin plate model and a monoclinic Reissner-Mindlin plate model with thermal deformation, two-way coupled piezoelectric effect and pyroelectric effect is constructed using the variational asymptotic method, without any ad hoc assumptions. Total potential energy contains strain energy, electric potential energy and energy caused by temperature change. Three-dimensional strain field is built based on the concept of warping function and decomposition of the rotation tensor. The feature of small thickness and large in-plane dimension of plate structure …

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Delamination Of C/Pekk I-Beam Using Virtual Crack Closure Technique And Cohesive Zone Method, Greeshma Ramakrishna Apr 2015

Delamination Of C/Pekk I-Beam Using Virtual Crack Closure Technique And Cohesive Zone Method, Greeshma Ramakrishna

Open Access Theses

A damage study is conducted on a carbon epoxy/PEKK (poly-ether-ketone-ketone) thermoplastic composite I-Beam, with a pre crack of 100 mm modeled between the top flange and the filler (butt joint between filler and web). This project is in collaboration with Fokker Aerostructures, Netherlands and is part of the Thermoplastic Primary Aircraft Structure innovation program (TAPAS). The C/PEKK I-Beam is modeled after a section of the Gulfstream G650 aircraft's centre beam, which was previously a carbon fiber/epoxy hat-stiffened skin construction. The objective of the thesis is to identify if the crack propagates in the I-Beam within the load range that act …

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A Contribution Toward Better Understanding Of Overbanking Tendency In Fixed-Wing Aircraft, Nihad E. Daidzic Feb 2015

A Contribution Toward Better Understanding Of Overbanking Tendency In Fixed-Wing Aircraft, Nihad E. Daidzic

Journal of Aviation Technology and Engineering

The phenomenon of overbanking tendency for a rigid-body, fixed-wing aircraft is investigated. Overbanking tendency is defined as a spontaneous, unbalanced rolling moment that keeps increasing an airplane’s bank angle in steep turns and must be arrested by opposite aileron action. As stated by the Federal Aviation Administration, the overbanking tendency may lead to a loss of control, especially in instrument meteorological conditions. It was found in this study that the speed differential over wing halves in horizontal turns indeed creates a rolling moment that achieves maximum values for bank angles between 45 and 55 degrees. However, this induced rolling moment …

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