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

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

Field‐dependent relaxation and absolute nuclear shielding of 207Pb in liquid PbCl4

Relaxation times T1 and T2 of 207Pb in liquid PbCl4 have been studied for the purpose of establishing an absolute nuclear shielding scale for lead. T1 has been decomposed into scalar and spin‐rotation contributions using variable temperature measurements at the two field strengths 6.59 and 16.90 kG. T2 is much shorter than T1 and is strongly dominated by scalar coupling to chlorine. Knowledge of the scalar contributions to T1 and T2 determines the halogen relaxation times (τ35 = 7.15 μsec at 25°C), the lead‐chlorine coupling constant [(J(207Pb−35Cl) = 705 Hz)], and the reorientational correlation time (τθ = 1.72 × 10−11 sec at 25°C). A correlation time τJ for the angular momentum vector has been computed using J diffusion theory, but the value obtained appears to be too short (0.8–2.9 × 10−14 sec) to be meaningful in terms of classical diffusion of rigid molecules. Nevertheless, the known range of 207Pb chemical shifts places an absolute upper limit on τJ of 6 × 10−14 sec at 263°K. The physical significance of such short correlation times is discussed, and it is concluded that τJ probably describes collision‐induced distortions in the molecular structure. Experimental values of the spin‐rotation contribution to (T1)−1 are used in conjunction with estimated values of τJ to compute limiting values for the spin‐rotation constant that place limits on the paramagnetic part of the magnetic shielding constant. A shielding scale previously deduced from optical pumping data is discussed, and a source of possibly substantial error in this scale is pointed out.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70479/2/JCPSA6-60-3-1009-1.pd

Field dependence of nuclear magnetic relaxation of 207Pb in aqueous Pb(ClO4)2

Nuclear magnetic relaxation times of the 207Pb resonance have been measured as a function of temperature and concentration at field strengths of 16.9, 11.7, and 6.56 kG in aqueous Pb(ClO4)2. Longitudinal relaxation is composed of spin‐rotation, chemical shift anisotropy, and dipolar contributions in a 3.5M solution, while spin‐rotation strongly dominates the relaxation at all temperatures between the melting and boiling points in a 1.15M solution. T2 accurately equals T1 at 1.15M, as is expected for a dominant spin‐rotation interaction, but is 20–30% shorter in the 3.5M solution, possibly due to a minor relaxation component arising from scalar coupling to naturally abundant H217OH217O. Chemical shifts of 207Pb have also been measured in aqueous Pb(ClO4)2 and Pb(NO3)2. The chemical shift and relaxation data show that ClO4− penetrates the Pb+2 hydration sphere at concentrations above about 2M, but no effects of such penetration are seen at lower concentration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70168/2/JCPSA6-60-4-1522-1.pd

The Association Between Trauma History and Body Image, Depression, Posttraumatic Stress, and Relationship Satisfaction in Postpartum Women

The postpartum period can be a time of significant change and transition. Little is known regarding how a history of trauma may impact functioning during this critical time. The literature is consistent regarding the relationship between trauma and body image-related issues, but this has not been investigated with this population. While posttraumatic stress symptoms are considered a significant public health concern, the association between depression and interpersonal concerns has not been thoroughly explored. The purpose of this observational, cross-sectional study is to explore the relationship between trauma and body image, mood, and relationship satisfaction in postpartum women. Proposed Methods: English speaking adult women (age ≥ 18 years, N = 200) who gave birth in the past year and are currently in an intimate relationship will be eligible to participate in the study. Participants will be recruited through social media and online forums that focus on topics related to pregnancy and the postpartum period. Screened and eligible participants will be asked to complete surveys including a demographic and trauma history questionnaire, PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (PCL-5), Body Attitude Questionnaire (BAQ), Edinburgh Postnatal Depression Scale (EPDS), and The Couples Satisfaction Index (CSI). Survey data will be captured using REDCap. Proposed Hypotheses: Postpartum women who endorse a history of trauma will report significantly greater body image concerns and depressions levels, as well as lower relationship satisfaction compared to postpartum women who do not endorse a history of trauma. In postpartum women with a history of trauma, higher posttraumatic stress symptoms will be associated with greater body image concerns and depression levels, and lower relationship satisfaction. We will descriptively explore levels of body image concerns, depression levels, and relationship satisfaction in postpartum women who endorse a history of sexual trauma. Proposed Analyses: Descriptive statistics will be used to characterize the sample. Correlations will evaluate the relationship between demographic variables and outcome measures. Regression or independent samples t-tests will be utilized to evaluate the hypotheses. Implications: This research has important implications for postpartum women for both their therapeutic and medical care. Findings may clarify conceptualizations of trauma and, therefore, inform treatment strategies and trauma-informed postpartum care. Additionally, results may provide further support for universal screenings during postpartum to identify women at-risk of various perinatal psychosocial concerns

Subsonic panel method for designing wing surfaces from pressure distribution

An iterative method has been developed for designing wing section contours corresponding to a prescribed subcritical distribution of pressure. The calculations are initialized by using a surface panel method to analyze a baseline wing or wing-fuselage configuration. A first-order expansion to the baseline panel method equations is then used to calculate a matrix containing the partial derivative of potential at each control point with respect to each unknown geometry parameter. In every iteration cycle, the matrix is used both to calculate the geometry perturbation and to analyze the perturbed geometry. The distribution of potential on the perturbed geometry is established by simple linear extrapolation from the baseline solution. The extrapolated potential is converted to pressure by Bernoulli's equation. Not only is the accuracy of the approach good for very large perturbations, but the computing cost of each complete iteration cycle is substantially less than one analysis solution by a conventional panel method

Crew procedures development techniques

The study developed requirements, designed, developed, checked out and demonstrated the Procedures Generation Program (PGP). The PGP is a digital computer program which provides a computerized means of developing flight crew procedures based on crew action in the shuttle procedures simulator. In addition, it provides a real time display of procedures, difference procedures, performance data and performance evaluation data. Reconstruction of displays is possible post-run. Data may be copied, stored on magnetic tape and transferred to the document processor for editing and documentation distribution

Three-Dimensional Numerical Modeling of Magnetohydrodynamic Augmented Propulsion Experiment

Over the past several years, NASA Marshall Space Flight Center has engaged in the design and development of an experimental research facility to investigate the use of diagonalized crossed-field magnetohydrodynamic (MHD) accelerators as a possible thrust augmentation device for thermal propulsion systems. In support of this effort, a three-dimensional numerical MHD model has been developed for the purpose of analyzing and optimizing accelerator performance and to aid in understanding critical underlying physical processes and nonideal effects. This Technical Memorandum fully summarizes model development efforts and presents the results of pretest performance optimization analyses. These results indicate that the MHD accelerator should utilize a 45deg diagonalization angle with the applied current evenly distributed over the first five inlet electrode pairs. When powered at 100 A, this configuration is expected to yield a 50% global efficiency with an 80% increase in axial velocity and a 50% increase in centerline total pressure