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Full-Text Articles in Engineering

Comparisons Of Cooling Performance And Flow Characteristics Of A Combustor Liner Plate With Compound Angle And Simple Angle Effusion Holes, Hwabhin Kwon, Phillip M. Ligrani, Sneha R. Vanga, Heesung Park Mar 2023

Comparisons Of Cooling Performance And Flow Characteristics Of A Combustor Liner Plate With Compound Angle And Simple Angle Effusion Holes, Hwabhin Kwon, Phillip M. Ligrani, Sneha R. Vanga, Heesung Park

PRC-Affiliated Research

The present investigation considers a unique compound angle arrangement, never previously considered, with α = 30°, β = ±30°, such that the compound angle of the effusion holes changes from β = +30° to β = −30°, as adjacent rows of effusion holes are encountered. Also provided are data for comparison from a simple angle configuration with α = 30°, β = 0°. Coolant is supplied to both effusion hole arrays using arrays of impingement cooling jets. The results of the numerical simulations are obtained using the ANSYS FLUENT V 21.1 numerical code, with a shear stress transport (SST) k–ω …


Feasibility Of Low-Enriched Uranium Fueled Nuclear Thermal Propulsion In The Low-Thrust Region Below 16klbf, Samantha B. Rawlins, Dale L. Thomas Sep 2022

Feasibility Of Low-Enriched Uranium Fueled Nuclear Thermal Propulsion In The Low-Thrust Region Below 16klbf, Samantha B. Rawlins, Dale L. Thomas

PRC-Affiliated Research

No abstract provided.


Flow And Heat Transfer Characteristics In A Pre-Swirl Rotor-Stator Cavity, Xiaoyu Yang, Zhong Ren, Jing Ren, Philip M. Ligrani Feb 2022

Flow And Heat Transfer Characteristics In A Pre-Swirl Rotor-Stator Cavity, Xiaoyu Yang, Zhong Ren, Jing Ren, Philip M. Ligrani

PRC-Affiliated Research

The present study investigates flow and heat transfer characteristics in a rotor-stator pre-swirl system. Considered are rotational Reynolds numbers ReФ ranging from 3.4 × 105 to 6.8 × 105, with jet Reynolds numbers Rew of approximately 8.8 × 104 to 3.81 × 105, and associated turbulent flow parameter λT = Cw/ReФ0.8 varying from 0 to 0.4. Experimentally-measured and numerically-predicted results illustrate the combined and separate influences of jet impingement and rotor entrainment, as they affect and govern flow and heat transfer characteristics within the cavity. These results show that the relative strength of the two effects varies with ReФ and …


Small Hall Effect Thruster With 3d Printed Discharge Channel: Design And Thrust Measurements, Ethan P. Hopping, Wensheng Huang, Kunning G. Xu Aug 2021

Small Hall Effect Thruster With 3d Printed Discharge Channel: Design And Thrust Measurements, Ethan P. Hopping, Wensheng Huang, Kunning G. Xu

PRC-Affiliated Research

Citation: Hopping, E.P.; Huang, W.; Xu, K.G. Small Hall Effect Thruster with 3D Printed Discharge Channel: Design and Thrust Measurements. Aerospace 2021, 8, 227. https:// Abstract: This paper presents the design and performance of the UAH-78AM, a low-power small Hall effect thruster. The goal of this work is to assess the feasibility of using low-cost 3D printing to create functioning Hall thrusters, and study how 3D printing can expand the design space. The thruster features a 3D printed discharge channel with embedded propellant distributor. Multiple materials were tested including ABS, ULTEM, and glazed ceramic. Thrust measurements were obtained at the …


Small Hall Effect Thruster With 3d Printed Discharge Channel: Design And Thrust Measurements, Ethan P. Hopping, Wensheng Huang, Kunning G. Xu Aug 2021

Small Hall Effect Thruster With 3d Printed Discharge Channel: Design And Thrust Measurements, Ethan P. Hopping, Wensheng Huang, Kunning G. Xu

PRC-Affiliated Research

Citation: Hopping, E.P.; Huang, W.; Xu, K.G. Small Hall Effect Thruster with 3D Printed Discharge Channel: Design and Thrust Measurements. Aerospace 2021, 8, 227. https:// Abstract: This paper presents the design and performance of the UAH-78AM, a low-power small Hall effect thruster. The goal of this work is to assess the feasibility of using low-cost 3D printing to create functioning Hall thrusters, and study how 3D printing can expand the design space. The thruster features a 3D printed discharge channel with embedded propellant distributor. Multiple materials were tested including ABS, ULTEM, and glazed ceramic. Thrust measurements were obtained at the …


Thermochemistry Of Combustion In Polyvinyl Alcohol + Hydroxylammonium Nitrate, James K. Baird, Robert A. Frederick Jr. May 2021

Thermochemistry Of Combustion In Polyvinyl Alcohol + Hydroxylammonium Nitrate, James K. Baird, Robert A. Frederick Jr.

PRC-Affiliated Research

A mixture of polyvinyl alcohol (PVA) and hydroxylammoniun nitrate (HAN) forms a gummy solid known as a plastisol, which is ionically conducting. When an electrostatic potential of 200 V DC is applied across the plastisol, it ignites. Combustion ceases upon removal of the applied voltage. The products of PVA + HAN combustion are known to include the molecular gases carbon monoxide, carbon dioxide, water, nitrogen, and hydrogen. When the electric field within the plastisol is spatially uniform, combustion occurs preferentially at the anode. The fact that HAN is an ionic conductor suggests that the mechanism of combustion is electrolytic in …


Thermochemistry Of Combustion In Polyvinyl Alcohol + Hydroxylammonium Nitrate, James K. Baird, Robert A. Frederick Jr. May 2021

Thermochemistry Of Combustion In Polyvinyl Alcohol + Hydroxylammonium Nitrate, James K. Baird, Robert A. Frederick Jr.

PRC-Affiliated Research

A mixture of polyvinyl alcohol (PVA) and hydroxylammoniun nitrate (HAN) forms a gummy solid known as a plastisol, which is ionically conducting. When an electrostatic potential of 200 V DC is applied across the plastisol, it ignites. Combustion ceases upon removal of the applied voltage. The products of PVA + HAN combustion are known to include the molecular gases carbon monoxide, carbon dioxide, water, nitrogen, and hydrogen. When the electric field within the plastisol is spatially uniform, combustion occurs preferentially at the anode. The fact that HAN is an ionic conductor suggests that the mechanism of combustion is electrolytic in …


Louver Slot Cooling And Full-Coverage Film Cooling With A Combination Internal Coolant Supply, Austin J. Click, Phillip M. Ligrani, Maggie Hockensmith, Joseph Knox, Chandler Larson, Avery Fairbanks, Federico Liberayore, Rajeshriben Patel Feb 2021

Louver Slot Cooling And Full-Coverage Film Cooling With A Combination Internal Coolant Supply, Austin J. Click, Phillip M. Ligrani, Maggie Hockensmith, Joseph Knox, Chandler Larson, Avery Fairbanks, Federico Liberayore, Rajeshriben Patel

PRC-Affiliated Research

Within the present investigation, a louver slot is employed upstream of an array full-coverage film cooling holes. Cooling air is supplied using a combination arrangement, with cross-flow and impingement together. The louver consists of a row of film cooling holes, contained within a specially designed device that concentrates and directs the coolant from a slot, so that it then advects as a layer downstream along the test surface. This louver-supplied coolant is then supplemented by coolant which emerges from different rows of downstream film cooling holes. The same coolant supply passage is employed for the louver row of holes, as …


Louver Slot Cooling And Full-Coverage Film Cooling With A Combination Internal Coolant Supply, Austin J. Click, Phillip M. Ligrani, Maggie Hockensmith, Joseph Knox, Chandler Larson, Avery Fairbanks, Federico Liberayore, Rajeshriben Patel Feb 2021

Louver Slot Cooling And Full-Coverage Film Cooling With A Combination Internal Coolant Supply, Austin J. Click, Phillip M. Ligrani, Maggie Hockensmith, Joseph Knox, Chandler Larson, Avery Fairbanks, Federico Liberayore, Rajeshriben Patel

PRC-Affiliated Research

Within the present investigation, a louver slot is employed upstream of an array full-coverage film cooling holes. Cooling air is supplied using a combination arrangement, with cross-flow and impingement together. The louver consists of a row of film cooling holes, contained within a specially designed device that concentrates and directs the coolant from a slot, so that it then advects as a layer downstream along the test surface. This louver-supplied coolant is then supplemented by coolant which emerges from different rows of downstream film cooling holes. The same coolant supply passage is employed for the louver row of holes, as …


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 …


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 …