Pre-Flight Ground Testing of the Full-Scale FRESH FX-1 at Fully Duplicated Flight Conditions

2007 ◽  
Author(s):  
Timothy Wadhams ◽  
Matthew MacLean ◽  
Michael Holden ◽  
Eric Mundy
Keyword(s):  
Full Scale ◽  
Ground Testing

Pre-Flight Ground Testing of the Full-Scale HIFiRE-1 at Fully Duplicated Flight Conditions

2008 ◽  
Author(s):  
Tim P. Wadhams ◽  
Matthew G. MacLean ◽  
Michael S. Holden ◽  
Erik Mundy
Keyword(s):  
Full Scale ◽  
Ground Testing

scholarly journals Complex Flow Generation and Development in a Full-Scale Turbofan Inlet

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Tamara Guimarães ◽  
K. Todd Lowe ◽  
Walter F. O'Brien
Keyword(s):  
Secondary Flow ◽  
Full Scale ◽  
Stereoscopic Particle Image Velocimetry ◽  
Complex Flow ◽  
Mean Velocity ◽  
Ground Testing ◽  
Turbofan Engines ◽  
Flow Generation ◽  
Image Velocimetry ◽  
The Mean

The future of aviation relies on the integration of airframe and propulsion systems to improve aerodynamic performance and efficiency of aircraft, bringing design challenges, such as the ingestion of nonuniform flows by turbofan engines. In this work, we describe the behavior of a complex distorted inflow in a full-scale engine rig. The distortion, as in engines on a hybrid wing body (HWB) type of aircraft, is generated by a 21-in diameter StreamVane, an array of vanes that produce prescribed secondary flow distributions. Data are acquired using stereoscopic particle image velocimetry (PIV) at three measurement planes along the inlet of the research engine (Reynolds number of 2.4 × 106). A vortex dynamics-based model, named StreamFlow, is used to predict the mean secondary flow development based on the experimental data. The mean velocity profiles show that, as flow develops axially, the vortex present in the profile migrates clockwise, opposite to the rotation of the fan, and toward the spinner of the engine. The turbulent stresses indicate that the center of the vortex meanders around a preferred location, which tightens as flow gets closer to the fan, yielding a smaller radius mean vortex near the fan. Signature features of the distortion device are observed in the velocity gradients, showing the wakes generated by the distortion screen vanes in the flow. The results obtained shed light onto the aerodynamics of swirling flows representative of distorted turbofan inlets, while further advancing the understanding of the complex vane technology presented herein for advanced ground testing.

Complex Flow Generation and Development in a Full-Scale Turbofan Inlet

2017 ◽  
Author(s):  
Tamara Guimarães ◽  
K. Todd Lowe ◽  
Walter F. O’Brien
Keyword(s):  
Fuel Efficiency ◽  
Full Scale ◽  
Complex Flow ◽  
Body Type ◽  
Mean Velocity ◽  
Ground Testing ◽  
Turbofan Engines ◽  
Velocity Gradients ◽  
Flow Generation ◽  
Image Velocimetry

The future of aviation relies on the integration of airframe and propulsion systems to increase fuel efficiency and improve the aerodynamic performance of aircraft. This need brings design challenges, such as the ingestion of non-uniform flows by turbofan engines. In this work, we seek to understand the behavior of a complex distorted inflow in a full-scale engine rig. A 21-inch diameter distortion screen previously designed is used to mimic the behavior of an adverse inlet flow encountered by a hybrid wing body type of aircraft. Three measurement planes along the inlet of the research engine are selected for the acquisition of data using particle image velocimetry at a duct diameter Reynolds number of 2.6 million. The resulting mean velocity profiles, velocity gradients and turbulent stresses are analyzed in order to describe the evolution of the flow along the inlet of the turbofan engine and as it approaches the fan face. As flow develops downstream, the vortex present in the profile migrates clockwise, opposite to the rotation of the fan, and towards the spinner of the engine. The turbulent stresses indicate that the center of the vortex meanders around a preferred location, and that location tightens as flow gets closer to the fan, yielding a smaller radius mean vortex near the fan. An analysis of velocity gradients shows the influence of the distortion screen in the flow, mainly in the streamwise direction, where signature features of the distortion device are observed, as an effect from the wakes of the vanes. The results obtained shed light onto the aerodynamics of swirling flows representative of distorted turbofan inlets, while further advancing the understanding of the complex vane technology presented herein for advanced ground testing of swirling inflows.

Relation of Statistically Significant, Abnormal, and Typical WAIS-R VIQ-PIQ Discrepancies to Full Scale IQs

2000 ◽  
Vol 16 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Louis M. Hsu ◽  
Judy Hayman ◽  
Judith Koch ◽  
Debbie Mandell
Keyword(s):  
Graphical Method ◽  
The United States ◽  
Full Scale ◽  
True Score ◽  
Absolute Value ◽  
Normative Population ◽  
The Us ◽  
The Mean ◽  
And Performance ◽  
Quadratic Models

Summary: In the United States' normative population for the WAIS-R, differences (Ds) between persons' verbal and performance IQs (VIQs and PIQs) tend to increase with an increase in full scale IQs (FSIQs). This suggests that norm-referenced interpretations of Ds should take FSIQs into account. Two new graphs are presented to facilitate this type of interpretation. One of these graphs estimates the mean of absolute values of D (called typical D) at each FSIQ level of the US normative population. The other graph estimates the absolute value of D that is exceeded only 5% of the time (called abnormal D) at each FSIQ level of this population. A graph for the identification of conventional “statistically significant Ds” (also called “reliable Ds”) is also presented. A reliable D is defined in the context of classical true score theory as an absolute D that is unlikely (p < .05) to be exceeded by a person whose true VIQ and PIQ are equal. As conventionally defined reliable Ds do not depend on the FSIQ. The graphs of typical and abnormal Ds are based on quadratic models of the relation of sizes of Ds to FSIQs. These models are generalizations of models described in Hsu (1996) . The new graphical method of identifying Abnormal Ds is compared to the conventional Payne-Jones method of identifying these Ds. Implications of the three juxtaposed graphs for the interpretation of VIQ-PIQ differences are discussed.

A Modification of the Payne-Jones Method of Identifying Abnormal Differences in WISC-R Performance and Verbal IQ's

1996 ◽  
Vol 12 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Louis M. Hsu
Keyword(s):  
Full Scale ◽  
True Score ◽  
Verbal Iq ◽  
Score Difference ◽  
The Difference ◽  
And Performance

The difference (D) between a person's Verbal IQ (VIQ) and Performance IQ (PIQ) has for some time been considered clinically meaningful ( Kaufman, 1976 , 1979 ; Matarazzo, 1990 , 1991 ; Matarazzo & Herman, 1985 ; Sattler, 1982 ; Wechsler, 1984 ). Particularly useful is information about the degree to which a difference (D) between scores is “abnormal” (i.e., deviant in a standardization group) as opposed to simply “reliable” (i.e., indicative of a true score difference) ( Mittenberg, Thompson, & Schwartz, 1991 ; Silverstein, 1981 ; Payne & Jones, 1957 ). Payne and Jones (1957) proposed a formula to identify “abnormal” differences, which has been used extensively in the literature, and which has generally yielded good approximations to empirically determined “abnormal” differences ( Silverstein, 1985 ; Matarazzo & Herman, 1985 ). However applications of this formula have not taken into account the dependence (demonstrated by Kaufman, 1976 , 1979 , and Matarazzo & Herman, 1985 ) of Ds on Full Scale IQs (FSIQs). This has led to overestimation of “abnormality” of Ds of high FSIQ children, and underestimation of “abnormality” of Ds of low FSIQ children. This article presents a formula for identification of abnormal WISC-R Ds, which overcomes these problems, by explicitly taking into account the dependence of Ds on FSIQs.

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