Numerical Investigation of a 1/3- and Full-Scale Partially-Dressed Small Business Jet Landing Gear

2012 ◽  
Author(s):  
Mohammad Tabesh ◽  
George Waller
Keyword(s):  
Small Business ◽  
Numerical Investigation ◽  
Landing Gear ◽  
Full Scale ◽  
Business Jet

Numerical Investigation of the Performance of a Roadside Safety Barrier Located Behind the Break Point of a Slope

2011 ◽  
Author(s):  
M. Mongiardini ◽  
J. D. Reid
Keyword(s):  
Numerical Investigation ◽  
Experimental Tests ◽  
Break Point ◽  
Full Scale ◽  
Crash Test ◽  
Construction Costs ◽  
Roadside Safety ◽  
The Road ◽  
Safety Barrier ◽  
Mechanically Stabilized

Numerical simulations allow engineers in roadside safety to investigate the safety of retrofit designs minimizing or, in some cases, avoiding the high costs related to the execution of full-scale experimental tests. This paper describes the numerical investigation made to assess the performance of a roadside safety barrier when relocated behind the break point of a 3H:1V slope, found on a Mechanically Stabilized Earth (MSE) system. A safe barrier relocation in the slope would allow reducing the installation width of the MSE system by an equivalent amount, thus decreasing the overall construction costs. The dynamics of a pick-up truck impacting the relocated barrier and the system deformation were simulated in detail using the explicit non-linear dynamic finite element code LS-DYNA. The model was initially calibrated and subsequently validated against results from a previous full-scale crash test with the barrier placed at the slope break point. After a sensitivity analysis regarding the role of suspension failure and tire deflation on the vehicle stability, the system performance was assessed when it was relocated into the slope. Two different configurations were considered, differing for the height of the rail respect to the road surface and the corresponding post embedment into the soil. Conclusions and recommendations were drawn based on the results obtained from the numerical analysis.

Numerical Investigation On Flow Generated by Invent Mixer In Full-Scale Wastewater Stirred Tank

2014 ◽  
Vol 8 (4) ◽  
pp. 503-517 ◽  
Author(s):  
A. A. Alleyne ◽  
S. Xanthos ◽  
K. Ramalingam ◽  
K. Temel ◽  
H. Li ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Full Scale ◽  
Stirred Tank

scholarly journals Full-Scale Turbofan Demonstration of a Deployable Engine Air-Brake for Drag Management Applications1

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Parthiv N. Shah ◽  
Gordon Pfeiffer ◽  
Rory Davis ◽  
Thomas Hartley ◽  
Zoltán Spakovszky
Keyword(s):  
Passive Control ◽  
Radial Pressure ◽  
Full Scale ◽  
Noise Sources ◽  
Fuel Burn ◽  
Business Jet ◽  
Readiness Level ◽  
Deployable Mechanism ◽  
Swirl Vane ◽  
Aircraft Application

This paper presents the design and full-scale ground-test demonstration of an engine air-brake (EAB) nozzle that uses a deployable swirl vane mechanism to switch the operation of a turbofan's exhaust stream from thrust generation to drag generation during the approach and/or descent phase of flight. The EAB generates a swirling outflow from the turbofan exhaust nozzle, allowing an aircraft to generate equivalent drag in the form of thrust reduction at a fixed fan rotor speed. The drag generated by the swirling exhaust flow is sustained by the strong radial pressure gradient created by the EAB swirl vanes. Such drag-on-demand is an enabler to operational benefits such as slower, steeper, and/or aeroacoustically cleaner flight on approach, addressing the aviation community's need for active and passive control of aeroacoustic noise sources and access to confined airports. Using NASA's technology readiness level (TRL) definitions, the EAB technology has been matured to a level of six, i.e., a fully functional prototype. The TRL-maturation effort involved design, fabrication, assembly, and ground-testing of the EAB's deployable mechanism on a full-scale, mixed-exhaust, medium-bypass-ratio business jet engine (Williams International FJ44-4A) operating at the upper end of typical approach throttle settings. The final prototype design satisfied a set of critical technology demonstration requirements that included (1) aerodynamic equivalent drag production equal to 15% of nominal thrust in a high-powered approach throttle setting (called dirty approach), (2) excess nozzle flow capacity and fuel burn reduction in the fully deployed configuration, (3) acceptable engine operability during dynamic deployment and stowing, (4) deployment time of 3–5 s, (5) stowing time under 0.5 s, and (6) packaging of the mechanism within a notional engine cowl. For a typical twin-jet aircraft application, a constant-speed, steep approach analysis suggests that the EAB drag could be used without additional external airframe drag to increase the conventional glideslope from 3 deg to 4.3 deg, with about 3 dB noise reduction at a fixed observer location.

scholarly journals Full-Scale Turbofan Demonstration of a Deployable Engine Air-Brake for Drag Management Applications

2016 ◽  
Author(s):  
Parthiv N. Shah ◽  
Gordon Pfeiffer ◽  
Rory Davis ◽  
Thomas Hartley ◽  
Zoltán Spakovszky
Keyword(s):  
Passive Control ◽  
Radial Pressure ◽  
Full Scale ◽  
Noise Sources ◽  
Fuel Burn ◽  
Business Jet ◽  
Readiness Level ◽  
Deployable Mechanism ◽  
Swirl Vane ◽  
Aircraft Application

This paper presents the design and full-scale ground-test demonstration of an engine air-brake (EAB) nozzle that uses a deployable swirl vane mechanism to switch the operation of a turbofan’s exhaust stream from thrust generation to drag generation during the approach and/or descent phase of flight. The EAB generates a swirling outflow from the turbofan exhaust nozzle, allowing an aircraft to generate equivalent drag in the form of thrust reduction at a fixed fan rotor speed. The drag generated by the swirling exhaust flow is sustained by the strong radial pressure gradient created by the EAB swirl vanes. Such drag-on-demand is an enabler to operational benefits such as slower, steeper, and/or aeroacoustically cleaner flight on approach, addressing the aviation community’s need for active and passive control of aeroacoustic noise sources and access to confined airports. Using NASA’s Technology Readiness Level (TRL) definitions, the EAB technology has been matured to a level of 6, i.e., a fully functional prototype. The TRL-maturation effort involved design, fabrication, assembly, and ground-testing of the EAB’s deployable mechanism on a full-scale, mixed-exhaust, medium-bypass-ratio business jet engine (Williams International FJ44-4A) operating at the upper end of typical approach throttle settings. The final prototype design satisfied a set of critical technology demonstration requirements that included (1) aerodynamic equivalent drag production equal to 15% of nominal gross thrust in a high-powered approach throttle setting (called dirty approach), (2) excess nozzle flow capacity and fuel burn reduction in the fully deployed configuration, (3) acceptable engine operability during dynamic deployment and stowing, (4) deployment time of 3–5 seconds, (5) stowing time under 0.5 second, and (6) packaging of the mechanism within a notional engine cowl. For a typical twin-jet aircraft application, a constant-speed, steep approach analysis suggests that the EAB drag could be used without additional external airframe drag to increase the conventional glideslope from 3 to 4.3 degrees, with about 3 dB noise reduction at a fixed observer location.

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