Theoretical fan velocity distortions due to inlets and nozzles

Nonuniform velocity profiles imposed on the propulsion system fan can cause fan blade stresses and thrust losses. A theoretical parametric study of the effects of inlets with 0 deg and 90 deg nozzle deflection on the velocity profile at a hypothetical fan is presented. The parameters investigated are fan-to-nozzle spacing and inlet centerline offset. The interaction between the inlet and nozzle is also investigated. The study is made using a two-dimensional analysis

Theoretical study of VTOL tilt-nacelle axisymmetric inlet geometries

A systematic theoretical study of VTOL tilt-nacelle inlet design parameters is reported. The parameters considered are internal-lip contraction ratio, internal-lip major-to-minor axis ratio, diffuser-exit-area to throat-area ratio, maximum diffuser wall angle and shape. Each of the inlets was analyzed at the same given flow condition of free-stream velocity, angle between the free stream and centerline of the inlet, and diffuser-exit Mach number. The effects of these geometric parameters on surface static-pressure distribution, peak surface Mach number, diffusion velocity ratio, and tendency for the inlet flow to separate are presented

Development of MCAERO wing design panel method with interactive graphics module

A reliable and efficient iterative method has been developed for designing wing section contours corresponding to a prescribed subcritical pressure distribution. The design process is initialized by using MCAERO (MCAIR 3-D Subsonic Potential Flow Analysis Code) to analyze a baseline configuration. A second program DMCAERO is then used to calculate a matrix containing the partial derivative of potential at each control point with respect to each unknown geometry parameter by applying a first-order expansion to the baseline equations in MCAERO. This matrix is calculated only once but is used in each iteration cycle to calculate the geometry perturbation and to analyze the perturbed geometry. The potential on the new geometry is calculated by linear extrapolation from the baseline solution. This extrapolated potential is converted to velocity by numerical differentiation, and velocity is converted to pressure by using Bernoulli's equation. There is an interactive graphics option which allows the user to graphically display the results of the design process and to interactively change either the geometry or the prescribed pressure distribution

Subsonic panel method for the efficient analysis of multiple geometry perturbations

An accurate and efficient method was developed for the aerodynamic analysis of a series of arbitrary small geometry perturbations to a given baseline configuration. The method is appropriate for wing-fuselage configurations in incompressible potential flow. Mathematical formulations are presented for three computer programs that are employed. The first program is a conventional surface panel method for calculating the baseline singularity distribution. The second program calculates a partial derivative matrix. Each element of the matrix is the rate of change of singularity strength at one point with respect to a surface coordinate of a different point. For each baseline configuration, the calculated quantities from the first two programs establish an input file for the third. The third program calculates the surface pressure distribution and forces and moments for a series of geometry perturbations

Determinants of body fatness

Between 1960 and 1961 anthropometric measurements, including skinfold thicknesses, were recorded on offspring aged 2 to 15 years in 330 families. Between 1976 and 1977 repeat skinfold measurements have been made on 318 (88#) of the male offspring and 303 (86#) of the female offspring, who now range in age from 17 to 30 years. Skinfold measurements were taken at the triceps, subscapular, suprailiac and biceps sites. The prediction from childhood values of adult individual skinfold measurements was found to vary from age to age in childhood and from site to site. No obvious pattern appeared and no one skinfold emerged as a more reliable predictor than any other. Where prediction was possible, the accuracies of the predictions were estimated to lie in 95% of cases between 13-1% and 2^.2# in the males and between 10.6# and 26.2# in the females. Calculations were repeated using the four skinfold measurements combined. The prediction from childhood values of the adult combined measurements, while more consistent than for the individual skinfolds, continued to vary from age to age in childhood. Where prediction was possible, the accuracies of the predictions were estimated to lie in 95# of cases between 10.6# and 18.0# in the males and between 8.0# and 18.C# in the females. No greater relationship between childhood and adult skinfold measurements was found in the group selected with a childhood triceps or subscapular skinfold on or above the 75th centile. The overall correlations between childhood and adult fatness levels, calculated from standardised scores, were O.56 and 0.^5 in the males and females respectively. It is concluded that there is a moderate relationship between fatness levels in childhood and in adult life; a relationshp in which room is left to manoeuvre. This is also a family study in which resemblances in body fatness have been assessed between 186 fathers, 211 mothers, 378 sons and 372 daughters. Amongst the offspring were 206 twin pairs. No resemblances were found between parents and their offspring either as children or as adults. Midparent-offspring correlations were also not significant. In this study, parents and offspring at the time of measurement were not, largely, sharing common family environments. This suggests the common family environment to have been an important factor in determining resemblances previously noted between relatives. The adult monozygotic twins resembled one another closely, as had been the case in childhood. The adult dizygotic male twins tended to resemble one another more closely than had been the case in childhood. The adult dizygotic female twins, by contrast, did not resemble one another at all. The similarities and differences found between the twins mirrored the similarities and differences noted between their lifestyles and habits. That the resemblances found were largely environmentally determined was supported by the finding that while the twins resembled one another, they did not resemble their singleton brothers or sisters. The family data are considered to indicate the importance of environmental factors in the determination of body fatness levels

Advance crew procedures development techniques: Procedures generation program requirements document

The Procedures Generation Program (PGP) is described as an automated crew procedures generation and performance monitoring system. Computer software requirements to be implemented in PGP for the Advanced Crew Procedures Development Techniques are outlined

Aurora Volume 20

College formerly located at Olivet, Illinois and known as Olivet University, 1912-1923; Olivet College, 1923-1939, Olivet Nazarene College, 1940-1986, Olivet Nazarene University, 1986-https://digitalcommons.olivet.edu/arch_yrbks/1022/thumbnail.jp

The Road to Adopting and Implementing Systemic Disclosure Changes in the Dallas County District Attorney’s Office

Discovery and Brady are currently two of the most discussed and debated topics in our criminal justice system. Americans have become more and more aware of the number of individuals convicted and incarcerated for crimes they did not commit. In 2007, in a very bold and innovative move, the Dallas County District Attorney’s Office created the Conviction Integrity Unit (CIU) to reexamine questionable convictions to determine if a particular defendant was in fact guilty