Investigation of a supersonic cruise fighter model flow field

An investigation was conducted in the Langley 16-Foot Transonic Tunnel to survey the flow field around a model of a supersonic cruise fighter configuration. Local values of angle of attack, side flow, Mach number, and total pressure ratio were measured with a single multi-holed probe in three survey areas on a model previously used for nacelle/nozzle integration investigations. The investigation was conducted at Mach numbers of 0.6, 0.9, and 1.2, and at angles of attack from 0 deg to 10 deg. The purpose of the investigation was to provide a base of experimental data with which theoretically determined data can be compared. To that end the data are presented in tables as well as graphically, and a complete description of the model geometry is included as fuselage cross sections and wing span stations. Measured local angles of attack were generally greater than free stream angle of attack above the wing and generally smaller below. There were large spanwise local angle-of-attack and side flow gradients above the wing at the higher free stream angles of attack

Static internal performance of convergent single-expansion-ramp nozzles with various combinations of internal geometric parameters

An investigation was conducted in the Static Test Facility of the Langley 16-Foot Transonic Tunnel to determine the effects of five geometric design parameters on the internal performance of convergent single expansion ramp nozzles. The effects of ramp chordal angle, initial ramp angle, flap angle, flap length, and ramp length were determined. All nozzles tested has a nominally constant throat area and aspect ratio. Static pressure distributions along the centerlines of the ramp and flap were also obtained for each configuration. Nozzle pressure ratio was varied up to 10.0 for all configurations

Static internal performance of a two-dimensional convergent-divergent nozzle with thrust vectoring

A parametric investigation of the static internal performance of multifunction two-dimensional convergent-divergent nozzles has been made in the static test facility of the Langley 16-Foot Transonic Tunnel. All nozzles had a constant throat area and aspect ratio. The effects of upper and lower flap angles, divergent flap length, throat approach angle, sidewall containment, and throat geometry were determined. All nozzles were tested at a thrust vector angle that varied from 5.60 tp 23.00 deg. The nozzle pressure ratio was varied up to 10 for all configurations

Multiaxis control power from thrust vectoring for a supersonic fighter aircraft model at Mach 0.20 to 2.47

The aeropropulsive characteristics of an advanced twin-engine fighter aircraft designed for supersonic cruise have been studied in the Langley 16-Foot Tansonic Tunnel and the Lewis 10- by 10-Foot Supersonic Tunnel. The objective was to determine multiaxis control-power characteristics from thrust vectoring. A two-dimensional convergent-divergent nozzle was designed to provide yaw vector angles of 0, -10, and -20 deg combined with geometric pitch vector angles of 0 and 15 deg. Yaw thrust vectoring was provided by yaw flaps located in the nozzle sidewalls. Roll control was obtained from differential pitch vectoring. This investigation was conducted at Mach numbers from 0.20 to 2.47. Angle of attack was varied from 0 to about 19 deg, and nozzle pressure ratio was varied from about 1 (jet off) to 28, depending on Mach number. Increments in force or moment coefficient that result from pitch or yaw thrust vectoring remain essentially constant over the entire angle-of-attack range of all Mach numbers tested. There was no effect of pitch vectoring on the lateral aerodynamic forces and moments and only very small effects of yaw vectoring on the longitudinal aerodynamic forces and moments. This result indicates little cross-coupling of control forces and moments for combined pitch-yaw vectoring

Effects of twin-vertical-tail parameters on twin-engine afterbody/nozzle aerodynamic characteristics

The Langley 16-foot transonic tunnel was used to determine the effects of several empennage and afterbody parameters on twin-engine aft-end aerodynamic characteristics. Model variables included twin-vertical-tail cant angle, toe angle, airfoil camber, and root-chord length and afterbody/engine interfairing shape. Tests were conducted over a Mach number range from 0.6 to 1.2 and over an angle-of-attack range from 2 deg to 10 deg. Nozzle pressure ratio was varied from 1.0 (jet off) to approximately 10.0

Investigation of installation effects on twin-engine convergent-divergent nozzles

An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine installation effects on convergent-divergent nozzles applicable to twin-engine reduced-power supersonic cruise aircraft. Tests were conducted at Mach numbers from 0.50 to 1.20, angles of attack from -5 deg to 9 deg, and at nozzle pressure ratios from jet off (1.0) to 8.0. The effects of empennage arrangement, nozzle length, and afterbody closure on total and component drag coefficients were investigated

Predictive Abilities of Neuropsychological Measures on Functional Outcomes in the Mild Cognitive Impairment (MCI) and Dementia Populations

During the aging process, a decline in ability to perform everyday tasks is commonly observed. This is increasingly so for those with dementia and is a diagnostic requirement. These daily tasks require certain cognitive skills which can be measured by various neuropsychological measures. The purpose of this study is to examine which neuropsychological measures are able to detect various deficits in self-reported activities of daily living (ADL) and instrumental activities of daily living (IADL) in individuals with mild cognitive impairment (MCI) and dementia. It is hypothesized that Trail Making Test– B (TMT-B) would be the most sensitive predictor in functional abilities for IADLs and ADLs in both the dementia and MCI populations. This is a quasi-experimental study using archival data and regression statistical models. The only statistically significant finding was that the TMT-B and Mini Mental Status Exam (MMSE) were predictive of IADL functioning within the MCI group, thus incorporating these measures in neuropsychological batteries is warranted. By knowing this information, neuropsychologists may refine their understanding of the utility of neuropsychological assessment and its relationship to disability, implement early intervention techniques to further preserve cognition, as well as assess the most appropriate environmental supports such as residential placements

Competition, Compromises, and Complicity: An Analysis of the Humanitarian Aid Sector

This paper analyzes humanitarian assistance to complex humanitarian emergencies to understand why suboptimal outcomes result even when humanitarians have ethical principles and good intentions. It focuses on the International Committee of the Red Cross, the United Nations, and Médecins Sans Frontières to understand their core principles before looking at how these principles operationalize during emergencies. Challenges arise due to complex relationships with donors, local actors, and recipients, along with issues of marketization and competition. This paper’s case studies of the post-genocide Rwandan refugee crisis and post-9/11 Afghanistan explore how humanitarian principles clash with such dilemmas. In the end, humanitarian organizations are often unable to adhere to principles in the midst of crises and make compromises of competition and complicity that lead to suboptimal outcomes for the people they are trying to help. Looking to modern emergencies in Syria, Yemen, and South Sudan, it is critical to understand these dynamics and seek to improve institutions of humanitarian aid to make assistance actually beneficial for those in need

Immobilization of electrochemical mediators to derivatives of a conducting polymer: toward the development of biofuel cells

The goal of this project is to develop a more efficient biofuel cell with the use of mediators and modification of electrode surfaces. This project focuses on a mediator, ferroceneaceticc acid (FcAA), which is expected to assist the transfer of electrons between the electrode surface and enzyme, resulting in a more efficient cell. This project is aimed toward the electropolymerization of monomer, coupling of mediator to monomer, and electropolymerization of mediator- monomer product. The monomer, hydroxymethyl 3,4-ethylenedioxythiophene (HMEDOT), was successfully polymerized onto the surface of a gold electrode using a solution of 0.01 M HMEDOT, 0.001 M β-CDSS, and ultrapure 18.2 MΩ*cm water from 0.0 V to 1.2 V at a scan rate of 5 mV/s. Coupling of the mediator, ferroceneacetic acid (FcAA), to the monomer, HMEDOT, using an esterification procedure was attempted. Future work is needed in order to optimize the coupling of FcAA to HMEDOT and to verify the product of the esterification. The product can then be electropolymerized onto a gold electrode using the parameters established above for HMEDOT

Effect of nozzle and vertical-tail variables on the performance of a 3-surface F-15 model at transonic Mach numbers

An investigation was conducted in the Langley 16 foot transonic tunnel to determine the longitudinal aerodynamic characteristics of twin two dimensional nozzles and twin baseline axisymmetric nozzles installed on a fully metric 0.047 scale model of the F-15 three surface configuration (canards, wing, horizontal tails). The effects on performance of two dimensional nozzle in flight thrust reversing, locations and orientation of the vertical tails, and deflections of the horizontal tails were also determined. Test data were obtained at static conditions and at Mach numbers from 0.60 to 1.20 over an angle of attack range from -2 deg to 15 deg. Nozzle pressure ratio was varied from jet off to about 6.5