Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Mechanical Engineering

3d Printing Nanostructured Thermoelectric Device, Qianru Jia, Collier Miers, Amy Marconnet Aug 2015

3d Printing Nanostructured Thermoelectric Device, Qianru Jia, Collier Miers, Amy Marconnet

The Summer Undergraduate Research Fellowship (SURF) Symposium

Thermoelectric materials convert thermal energy to electrical energy and vice versa. Thermoelectrics have attracted much attention and research efforts due to the possibility solving electronic cooling problems and reducing energy consumption through waste heat recovery. The efficiency of a thermoelectric material is determined by the dimensionless figure of merit ZT, which depends on both thermal and electrical properties. Researchers have worked for several decades to improve the ZT, but there had been little progress until nanomaterials and nanofabrication became widely available. Nanotechnology makes the ZT enhancement attainable by disconnecting the linkage between thermal and electrical transport. Printing customized, flexible thermoelectric …


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 …


The Effects Of Ivc Modulation On Modern Diesel Engines Equipped With Variable Valve Actuation At High Load And Speed, Troy E. Odstrcil, Gregory M. Shaver, Cody M. Allen Aug 2015

The Effects Of Ivc Modulation On Modern Diesel Engines Equipped With Variable Valve Actuation At High Load And Speed, Troy E. Odstrcil, Gregory M. Shaver, Cody M. Allen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Modern diesel compression engines are known for their increased durability, fuel economy and torque when compared with their spark ignition gasoline counterparts. These are some of the reasons why diesel engines are preferred in heavy duty applications such as trains and semi-trucks. During the Heavy Duty Federal Test Procedure transient drive cycle, or HDFTP, nearly 85% of the total fuel burned is at speeds greater than 2000 revolutions per minute (RPM) for the studied engine. Therefore, it is desirable to increase the fuel economy at these loads and speeds. It is hypothesized that the use of late intake valve close …


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 …


Improvement Of Diesel Engines At High Speeds Via Flexible Valve Actuation And Cylinder Deactivation, Dina M. Caicedo Parra, Gregory M. Shaver, Aswin Ramesh Aug 2015

Improvement Of Diesel Engines At High Speeds Via Flexible Valve Actuation And Cylinder Deactivation, Dina M. Caicedo Parra, Gregory M. Shaver, Aswin Ramesh

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the U.S fuel consumption is expected to increase over 20% from 2010 to 2020 especially in the heavy duty segment. As a consequence of the increase in production of heavy and light duty vehicles, regulations and stricter policies are being applied to the emissions of pollutants, including NOx, and soot. This study outlines strategies for using cylinder deactivation and intake valve closure (IVC) modulation to improve fuel economy and increase the rate at which NOx/soot-mitigating aftertreatment devices reach working temperatures. Effects of opening and squeezing variable geometry turbine (VGT) turbocharger were also analyzed. From the results it was observed …


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 …


Combustion Wave Propagation Enhancement Of A Nitrocellulose Solid Monopropellant, Omar R. Yehia, Shourya Jain, Li Qiao Aug 2015

Combustion Wave Propagation Enhancement Of A Nitrocellulose Solid Monopropellant, Omar R. Yehia, Shourya Jain, Li Qiao

The Summer Undergraduate Research Fellowship (SURF) Symposium

Improvement and control of the burning behavior and characteristics of solid fuels promise improved performance of systems ranging from solid rocket motors to microelectromechanical systems. Introducing methods to enhance combustion wave propagation velocities of solid propellants is a crucial step in realizing improved performance in rocket motors that use organic nitrate-based propellants. This work aims to enhance the burning characteristics of solid fuels through the use of thermally guided combustion waves. In order to increase the burning rate of solid nitrocellulose fuel layers, graphite sheets were used as thermally conductive bases in order to substantially improve heat transfer to unburned …


Numerical Solver For Multiphase Flows, Victor C B Sousa, Carlo Scalo Aug 2015

Numerical Solver For Multiphase Flows, Victor C B Sousa, Carlo Scalo

The Summer Undergraduate Research Fellowship (SURF) Symposium

The technological development of micro-scale electronic devices is bounded by the challenge of dissipating their heat output. Latent heat absorbed by a fluid during phase transition offers exceptional cooling capabilities while allowing for the design of compact heat exchangers. The understanding of heat transport dynamics in the context of multiphase flow physics is hampered by the limited access to detailed flow features offered by experimental measurements. Computational Fluid Dynamics (CFD) can overcome such difficulties by providing a complete description of the three-dimensional instantaneous flow field. Unfortunately, the majority of the numerical investigations in this field at Purdue are carried out …