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Full-Text Articles in Engineering

Double Wall Cooling Of An Effusion Plate With Simultaneous Cross Flow And Impingement Jet Array Internal Cooling, Phil Ligrani, Austin Click, David Ritchie, Federico Liberatore, Rajeshriben Patel, Yin-Hsiang Ho Dec 2019

Double Wall Cooling Of An Effusion Plate With Simultaneous Cross Flow And Impingement Jet Array Internal Cooling, Phil Ligrani, Austin Click, David Ritchie, Federico Liberatore, Rajeshriben Patel, Yin-Hsiang Ho

PRC-Affiliated Research

The present study considers comparisons of hot-side effusion plate results for a mainstream flow passage with CR = 1 and for a mainstream flow passage with CR = 4. The coolant supply arrangement for both CR contraction ratio values includes simultaneous use of cross flow and an impingement jet array. For the effusion cooled/hot surface, presented are spatially-resolved distributions of surface adiabatic film cooling effectiveness, and surface heat transfer coefficients (measured using infrared thermography). These results are given for main flow Reynolds numbers Rems of 89,900 to 95,800. For this main flow Reynolds number range, four different combination values of …


Double Wall Cooling Of An Effusion Plate With Simultaneous Cross Flow And Impingement Jet Array Internal Cooling, Phil Ligrani, Austin Click, David Ritchie, Federico Liberatore, Rajeshriben Patel, Yin-Hsiang Ho Dec 2019

Double Wall Cooling Of An Effusion Plate With Simultaneous Cross Flow And Impingement Jet Array Internal Cooling, Phil Ligrani, Austin Click, David Ritchie, Federico Liberatore, Rajeshriben Patel, Yin-Hsiang Ho

PRC-Affiliated Research

The present study considers comparisons of hot-side effusion plate results for a mainstream flow passage with CR = 1 and for a mainstream flow passage with CR = 4. The coolant supply arrangement for both CR contraction ratio values includes simultaneous use of cross flow and an impingement jet array. For the effusion cooled/hot surface, presented are spatially-resolved distributions of surface adiabatic film cooling effectiveness, and surface heat transfer coefficients (measured using infrared thermography). These results are given for main flow Reynolds numbers Rems of 89,900 to 95,800. For this main flow Reynolds number range, four different combination values of …


Double Wall Cooling Of An Effusion Plate With Simultaneous Cross Flow And Impingement Jet Array Internal Cooling, Phil Ligrani, Austin Click, David Ritchie, Federico Liberatore, Rajeshriben Patel, Yin-Hsiang Ho Dec 2019

Double Wall Cooling Of An Effusion Plate With Simultaneous Cross Flow And Impingement Jet Array Internal Cooling, Phil Ligrani, Austin Click, David Ritchie, Federico Liberatore, Rajeshriben Patel, Yin-Hsiang Ho

PRC-Affiliated Research

The present study considers comparisons of hot-side effusion plate results for a mainstream flow passage with CR = 1 and for a mainstream flow passage with CR = 4. The coolant supply arrangement for both CR contraction ratio values includes simultaneous use of cross flow and an impingement jet array. For the effusion cooled/hot surface, presented are spatially-resolved distributions of surface adiabatic film cooling effectiveness, and surface heat transfer coefficients (measured using infrared thermography). These results are given for main flow Reynolds numbers Rems of 89,900 to 95,800. For this main flow Reynolds number range, four different combination values of …


Analysis Of Shock Wave Unsteadiness Using Space And Time Correlations Applied To Shadowgraph Flow Visualization Data, Shannon Marko, Phillip M. Ligrani Dec 2019

Analysis Of Shock Wave Unsteadiness Using Space And Time Correlations Applied To Shadowgraph Flow Visualization Data, Shannon Marko, Phillip M. Ligrani

PRC-Affiliated Research

Unsteady flow characteristics of a normal shock wave, a lambda foot, and a separated turbulent boundary layer are investigated within a unique test section with supersonic inlet flow. The supersonic wind tunnel facility, containing this test section, provides a Mach number of approximately 1.54 at the test section entrance. Digitized shadowgraph flow visualization data are employed to visualize shock wave structure within the test section. These data are analyzed to determine shock wave unsteadiness characteristics, including grayscale spectral energy variations with frequency, as well as time and space correlations, which give coherence and time lag properties associated with perturbations associated …


Analysis Of Shock Wave Unsteadiness Using Space And Time Correlations Applied To Shadowgraph Flow Visualization Data, Shannon Marko, Phillip M. Ligrani Dec 2019

Analysis Of Shock Wave Unsteadiness Using Space And Time Correlations Applied To Shadowgraph Flow Visualization Data, Shannon Marko, Phillip M. Ligrani

PRC-Affiliated Research

Unsteady flow characteristics of a normal shock wave, a lambda foot, and a separated turbulent boundary layer are investigated within a unique test section with supersonic inlet flow. The supersonic wind tunnel facility, containing this test section, provides a Mach number of approximately 1.54 at the test section entrance. Digitized shadowgraph flow visualization data are employed to visualize shock wave structure within the test section. These data are analyzed to determine shock wave unsteadiness characteristics, including grayscale spectral energy variations with frequency, as well as time and space correlations, which give coherence and time lag properties associated with perturbations associated …


Analysis Of Shock Wave Unsteadiness Using Space And Time Correlations Applied To Shadowgraph Flow Visualization Data, Shannon Marko, Phillip M. Ligrani Dec 2019

Analysis Of Shock Wave Unsteadiness Using Space And Time Correlations Applied To Shadowgraph Flow Visualization Data, Shannon Marko, Phillip M. Ligrani

PRC-Affiliated Research

Unsteady flow characteristics of a normal shock wave, a lambda foot, and a separated turbulent boundary layer are investigated within a unique test section with supersonic inlet flow. The supersonic wind tunnel facility, containing this test section, provides a Mach number of approximately 1.54 at the test section entrance. Digitized shadowgraph flow visualization data are employed to visualize shock wave structure within the test section. These data are analyzed to determine shock wave unsteadiness characteristics, including grayscale spectral energy variations with frequency, as well as time and space correlations, which give coherence and time lag properties associated with perturbations associated …


Demonstration Of A Quasi-Cw Diode-Pumped Metastable Xenon Laser, Carl R. Sanderson, Charles W. Ballmann, Jiande Han, Amanda B. Clark, Brett H. Hokr, Kunning G. Xu, Michael C. Heaven Nov 2019

Demonstration Of A Quasi-Cw Diode-Pumped Metastable Xenon Laser, Carl R. Sanderson, Charles W. Ballmann, Jiande Han, Amanda B. Clark, Brett H. Hokr, Kunning G. Xu, Michael C. Heaven

PRC-Affiliated Research

In this work, we present the first demonstration of a quasi-continuous-wave diode-pumped metastable xenon laser at atmospheric pressures. Lasing in metastable noble gas species has received increased attention in the last few years as a possible high-power laser source. This demonstration shows that metastable xenon has a sufficiently broad absorption spectrum to be pumped with a broad-bandwidth diode laser. This implies that a high-power metastable xenon gas laser should be achievable using high-power pump diodes.


Demonstration Of A Quasi-Cw Diode-Pumped Metastable Xenon Laser, Carl R. Sanderson, Charles W. Ballmann, Jiande Han, Amanda B. Clark, Brett H. Hokr, Kunning G. Xu, Michael C. Heaven Nov 2019

Demonstration Of A Quasi-Cw Diode-Pumped Metastable Xenon Laser, Carl R. Sanderson, Charles W. Ballmann, Jiande Han, Amanda B. Clark, Brett H. Hokr, Kunning G. Xu, Michael C. Heaven

PRC-Affiliated Research

In this work, we present the first demonstration of a quasi-continuous-wave diode-pumped metastable xenon laser at atmospheric pressures. Lasing in metastable noble gas species has received increased attention in the last few years as a possible high-power laser source. This demonstration shows that metastable xenon has a sufficiently broad absorption spectrum to be pumped with a broad-bandwidth diode laser. This implies that a high-power metastable xenon gas laser should be achievable using high-power pump diodes.


Demonstration Of A Quasi-Cw Diode-Pumped Metastable Xenon Laser, Carl R. Sanderson, Charles W. Ballmann, Jiande Han, Amanda B. Clark, Brett H. Hokr, Kunning G. Xu, Michael C. Heaven Nov 2019

Demonstration Of A Quasi-Cw Diode-Pumped Metastable Xenon Laser, Carl R. Sanderson, Charles W. Ballmann, Jiande Han, Amanda B. Clark, Brett H. Hokr, Kunning G. Xu, Michael C. Heaven

PRC-Affiliated Research

In this work, we present the first demonstration of a quasi-continuous-wave diode-pumped metastable xenon laser at atmospheric pressures. Lasing in metastable noble gas species has received increased attention in the last few years as a possible high-power laser source. This demonstration shows that metastable xenon has a sufficiently broad absorption spectrum to be pumped with a broad-bandwidth diode laser. This implies that a high-power metastable xenon gas laser should be achievable using high-power pump diodes.


Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr. Oct 2019

Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr.

PRC-Affiliated Research

The ultimate design values for a friction stir weld (FSW) are not based on the average strength, but the lowest strength or outlier. Thus, the robustness of the process could be ultimately increased by understanding and minimizing the sources of data scatter within the mechanical properties of a FSW panel. Internal voids are known to result in reduced strength, but are detectable using non-destructive evaluation (NDE). Other metallurgical discontinuities, such as internal oxides, are difficult to detect using NDE and are often blamed for random variations in the mechanical properties of FSWs. Current efforts to minimize internal oxides within a …


Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr. Oct 2019

Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr.

PRC-Affiliated Research

The ultimate design values for a friction stir weld (FSW) are not based on the average strength, but the lowest strength or outlier. Thus, the robustness of the process could be ultimately increased by understanding and minimizing the sources of data scatter within the mechanical properties of a FSW panel. Internal voids are known to result in reduced strength, but are detectable using non-destructive evaluation (NDE). Other metallurgical discontinuities, such as internal oxides, are difficult to detect using NDE and are often blamed for random variations in the mechanical properties of FSWs. Current efforts to minimize internal oxides within a …


Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr. Oct 2019

Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr.

PRC-Affiliated Research

The ultimate design values for a friction stir weld (FSW) are not based on the average strength, but the lowest strength or outlier. Thus, the robustness of the process could be ultimately increased by understanding and minimizing the sources of data scatter within the mechanical properties of a FSW panel. Internal voids are known to result in reduced strength, but are detectable using non-destructive evaluation (NDE). Other metallurgical discontinuities, such as internal oxides, are difficult to detect using NDE and are often blamed for random variations in the mechanical properties of FSWs. Current efforts to minimize internal oxides within a …


Oh Production And Jet Length Of An Atmospheric-Pressure Plasma Jet For Soft And Biomaterial Treatment, Ryan P. Gott, Kunning G. Xu Oct 2019

Oh Production And Jet Length Of An Atmospheric-Pressure Plasma Jet For Soft And Biomaterial Treatment, Ryan P. Gott, Kunning G. Xu

PRC-Affiliated Research

Atmospheric-pressure plasma jets (APPJs) are currently being studied and developed for the biomedical, chemistry, and physics communities because of their ability to produce desirable reactive species at low temperatures and at atmospheric pressures. Due to the high particle densities, small scales, and nonequilibrium nature of these plasmas, they can be difficult to predict and compare across devices. In this article, a plasma jet is operated over a range of conditions and characterized by using optical emission spectroscopy (OES) and synchronized imaging. The effect of the operating conditions on the gas temperature, jet length, plasma formation, and reactive species produced is …


Oh Production And Jet Length Of An Atmospheric-Pressure Plasma Jet For Soft And Biomaterial Treatment, Ryan P. Gott, Kunning G. Xu Oct 2019

Oh Production And Jet Length Of An Atmospheric-Pressure Plasma Jet For Soft And Biomaterial Treatment, Ryan P. Gott, Kunning G. Xu

PRC-Affiliated Research

Atmospheric-pressure plasma jets (APPJs) are currently being studied and developed for the biomedical, chemistry, and physics communities because of their ability to produce desirable reactive species at low temperatures and at atmospheric pressures. Due to the high particle densities, small scales, and nonequilibrium nature of these plasmas, they can be difficult to predict and compare across devices. In this article, a plasma jet is operated over a range of conditions and characterized by using optical emission spectroscopy (OES) and synchronized imaging. The effect of the operating conditions on the gas temperature, jet length, plasma formation, and reactive species produced is …


Oh Production And Jet Length Of An Atmospheric-Pressure Plasma Jet For Soft And Biomaterial Treatment, Ryan P. Gott, Kunning G. Xu Oct 2019

Oh Production And Jet Length Of An Atmospheric-Pressure Plasma Jet For Soft And Biomaterial Treatment, Ryan P. Gott, Kunning G. Xu

PRC-Affiliated Research

Atmospheric-pressure plasma jets (APPJs) are currently being studied and developed for the biomedical, chemistry, and physics communities because of their ability to produce desirable reactive species at low temperatures and at atmospheric pressures. Due to the high particle densities, small scales, and nonequilibrium nature of these plasmas, they can be difficult to predict and compare across devices. In this article, a plasma jet is operated over a range of conditions and characterized by using optical emission spectroscopy (OES) and synchronized imaging. The effect of the operating conditions on the gas temperature, jet length, plasma formation, and reactive species produced is …


Application Of Acquisition Theory, Elizabeth Rose Cavin, Hillary Palmer, Paul Collopy Sep 2019

Application Of Acquisition Theory, Elizabeth Rose Cavin, Hillary Palmer, Paul Collopy

Von Braun Symposium Student Posters

No abstract provided.


Characterization Of A Pulse-Recharge Circuit For Puff, Nathan Schilling Sep 2019

Characterization Of A Pulse-Recharge Circuit For Puff, Nathan Schilling

Von Braun Symposium Student Posters

No abstract provided.


Design And Development Of An Autonomous Return Vehicle, Sean Widmier, An Nguyen, Colin Oberthur, Sean Mitchell, Fred Snopl Sep 2019

Design And Development Of An Autonomous Return Vehicle, Sean Widmier, An Nguyen, Colin Oberthur, Sean Mitchell, Fred Snopl

Von Braun Symposium Student Posters

No abstract provided.


Experimental And Numerical Analysis Of Quasi-Static Deformation Mechanisms Of Additively Manufactured Lattice Structures, Behzad Bahrami Babamiri Sep 2019

Experimental And Numerical Analysis Of Quasi-Static Deformation Mechanisms Of Additively Manufactured Lattice Structures, Behzad Bahrami Babamiri

Von Braun Symposium Student Posters

No abstract provided.


Evaluation Of Varying Surface Finishes On Thin-Walled Blown Powdered Deposition Inconel 625, Noah Naden, Giancarlo Puerto, Judy Schneider Sep 2019

Evaluation Of Varying Surface Finishes On Thin-Walled Blown Powdered Deposition Inconel 625, Noah Naden, Giancarlo Puerto, Judy Schneider

Von Braun Symposium Student Posters

No abstract provided.


Seeded Hydrogen In Nuclear Thermal Propulsion (Ntp) Engines, Dennis Nikitaev Sep 2019

Seeded Hydrogen In Nuclear Thermal Propulsion (Ntp) Engines, Dennis Nikitaev

Von Braun Symposium Student Posters

No abstract provided.


Synthesis Of Zif-8 For Carbon Dioxide Adsorption, Fausat Isu, Yu Lei Sep 2019

Synthesis Of Zif-8 For Carbon Dioxide Adsorption, Fausat Isu, Yu Lei

Von Braun Symposium Student Posters

No abstract provided.


Analyzing Failure Classifications For Patterns And Trends, Casey Eaton, Amanda Banks Sep 2019

Analyzing Failure Classifications For Patterns And Trends, Casey Eaton, Amanda Banks

Von Braun Symposium Student Posters

No abstract provided.


An Investigation Of Nasa Affordability Culture And Implications On Engineering Management, Jonathon Sullivan, Christopher White Sep 2019

An Investigation Of Nasa Affordability Culture And Implications On Engineering Management, Jonathon Sullivan, Christopher White

Von Braun Symposium Student Posters

No abstract provided.


Structure And Reactivity Of Single Site Ti Catalysts For Propylene Epoxidation, Zheng Lu, Xiaoyang Liu, Bin Zhang, Zhuoran Gan, Siwen Tang, Lu Ma, Tianpin Wu, George J. Nelson, Yong Qin, Heath C. Turner, Yu Lei Sep 2019

Structure And Reactivity Of Single Site Ti Catalysts For Propylene Epoxidation, Zheng Lu, Xiaoyang Liu, Bin Zhang, Zhuoran Gan, Siwen Tang, Lu Ma, Tianpin Wu, George J. Nelson, Yong Qin, Heath C. Turner, Yu Lei

PRC-Affiliated Research

Propylene epoxidation using molecular oxygen and hydrogen mixture on Au-based catalysts has attracted attention because of high propylene oxide selectivity and the use of an inexpensive and environmental friendly oxidant. Single-site titanium on metal oxide supports plays an important role in achieving high reactivity and selectivity in propylene epoxidation. Here we used TiO2 atomic layer deposition (ALD) to synthesize single-site titanium imbedded in the SiO2 framework for propylene epoxidation. High temperature calcination was used as post-treatment to control the titania structure and Tisingle bondO coordination number. Using UV–vis spectroscopy and X-ray absorption spectroscopy, we successfully established that under similar propylene …


Structure And Reactivity Of Single Site Ti Catalysts For Propylene Epoxidation, Zheng Lu, Xiaoyang Liu, Bin Zhang, Zhuoran Gan, Siwen Tang, Lu Ma, Tianpin Wu, George J. Nelson, Yong Qin, Heath C. Turner, Yu Lei Sep 2019

Structure And Reactivity Of Single Site Ti Catalysts For Propylene Epoxidation, Zheng Lu, Xiaoyang Liu, Bin Zhang, Zhuoran Gan, Siwen Tang, Lu Ma, Tianpin Wu, George J. Nelson, Yong Qin, Heath C. Turner, Yu Lei

PRC-Affiliated Research

Propylene epoxidation using molecular oxygen and hydrogen mixture on Au-based catalysts has attracted attention because of high propylene oxide selectivity and the use of an inexpensive and environmental friendly oxidant. Single-site titanium on metal oxide supports plays an important role in achieving high reactivity and selectivity in propylene epoxidation. Here we used TiO2 atomic layer deposition (ALD) to synthesize single-site titanium imbedded in the SiO2 framework for propylene epoxidation. High temperature calcination was used as post-treatment to control the titania structure and Tisingle bondO coordination number. Using UV–vis spectroscopy and X-ray absorption spectroscopy, we successfully established that under similar propylene …


Structure And Reactivity Of Single Site Ti Catalysts For Propylene Epoxidation, Zheng Lu, Xiaoyang Liu, Bin Zhang, Zhuoran Gan, Siwen Tang, Lu Ma, Tianpin Wu, George J. Nelson, Yong Qin, Heath C. Turner, Yu Lei Sep 2019

Structure And Reactivity Of Single Site Ti Catalysts For Propylene Epoxidation, Zheng Lu, Xiaoyang Liu, Bin Zhang, Zhuoran Gan, Siwen Tang, Lu Ma, Tianpin Wu, George J. Nelson, Yong Qin, Heath C. Turner, Yu Lei

PRC-Affiliated Research

Propylene epoxidation using molecular oxygen and hydrogen mixture on Au-based catalysts has attracted attention because of high propylene oxide selectivity and the use of an inexpensive and environmental friendly oxidant. Single-site titanium on metal oxide supports plays an important role in achieving high reactivity and selectivity in propylene epoxidation. Here we used TiO2 atomic layer deposition (ALD) to synthesize single-site titanium imbedded in the SiO2 framework for propylene epoxidation. High temperature calcination was used as post-treatment to control the titania structure and Tisingle bondO coordination number. Using UV–vis spectroscopy and X-ray absorption spectroscopy, we successfully established that under similar propylene …


Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris Aug 2019

Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris

PRC-Affiliated Research

The isobaric heat capacity and the coefficient of thermal expansion of a binary liquid mixture with a critical point of solution diverge as functions of temperature in the critical region. When the same liquids are used as solvents for chemical reactions, the van't Hoff plot of the extent of reaction diverges in the critical region. According to the phase rule, the physical and chemical properties are isomorphic in the sense that in each case the critical behavior is determined by three fixed thermodynamic intensive variables.


Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris Aug 2019

Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris

PRC-Affiliated Research

The isobaric heat capacity and the coefficient of thermal expansion of a binary liquid mixture with a critical point of solution diverge as functions of temperature in the critical region. When the same liquids are used as solvents for chemical reactions, the van't Hoff plot of the extent of reaction diverges in the critical region. According to the phase rule, the physical and chemical properties are isomorphic in the sense that in each case the critical behavior is determined by three fixed thermodynamic intensive variables.


Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris Aug 2019

Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris

PRC-Affiliated Research

The isobaric heat capacity and the coefficient of thermal expansion of a binary liquid mixture with a critical point of solution diverge as functions of temperature in the critical region. When the same liquids are used as solvents for chemical reactions, the van't Hoff plot of the extent of reaction diverges in the critical region. According to the phase rule, the physical and chemical properties are isomorphic in the sense that in each case the critical behavior is determined by three fixed thermodynamic intensive variables.