Results of LFC experiment on slotted swept supercritical airfoil in Langley's 8-foot transonic pressure tunnel

A large chord swept supercritical laminar-flow control (LFC) airfoil was designed, constructed, and tested in the Langley 8-foot Transonic Pressure Tunnel (TPT). The LFC airfoil experiment was established to provide basic information concerning the design and compatibility of high performance supercritical airfoils with suction boundary-layer control achieved through fine slots or porous surface concepts. Shockless pressure distribution was achieved. Full chord laminar flow was achieved on upper and lower surfaces. Full chord laminar flow was maintained at subcritical speeds and over large supercritical zones. Feasibility of combined suction laminarization and supercritical airfoil technology was demonstrated

The NASA Langley laminar-flow-control experiment on a swept, supercritical airfoil - Drag equations

The Langley Research Center has designed a swept, supercritical airfoil incorporating Laminar Flow Control for testing at transonic speeds. Analytical expressions have been developed and an evaluation made of the experimental section drag, composed of suction drag and wake drag, using theoretical design information and experimental data. The analysis shows that, although the sweep-induced boundary-layer crossflow influence on the wake drag is too large to be ignored and there is not a practical method for evaluating these crossflow effects on the experimental wake data, the conventional unswept 2-D wake-drag computation used in the reduction of the experimental data is at worst 10 percent too high

The NASA Langley laminar-flow-control experiment on a swept, supercritical airfoil: Suction coefficient analysis

A swept supercritical wing incorporating laminar flow control at transonic flow conditions was designed and tested. The definition of an experimental suction coefficient and a derivation of the compressible and incompressible formulas for the computation of the coefficient from measurable quantities is presented. The suction flow coefficient in the highest velocity nozzles is shown to be overpredicted by as much as 12 percent through the use of an incompressible formula. However, the overprediction on the computed value of suction drag when some of the suction nozzles were operating in the compressible flow regime is evaluated and found to be at most 6 percent at design conditions

The NASA Langley Laminar-Flow-Control (LFC) experiment on a swept, supercritical airfoil: Design overview

A large-chord, swept, supercritical, laminar-flow-control (LFC) airfoil was designed and constructed and is currently undergoing tests in the Langley 8 ft Transonic Pressure Tunnel. The experiment was directed toward evaluating the compatibility of LFC and supercritical airfoils, validating prediction techniques, and generating a data base for future transport airfoil design as part of NASA's ongoing research program to significantly reduce drag and increase aircraft efficiency. Unique features of the airfoil included a high design Mach number with shock free flow and boundary layer control by suction. Special requirements for the experiment included modifications to the wind tunnel to achieve the necessary flow quality and contouring of the test section walls to simulate free air flow about a swept model at transonic speeds. Design of the airfoil with a slotted suction surface, the suction system, and modifications to the tunnel to meet test requirements are discussed

The NASA Langley laminar-flow-control experiment on a swept, supercritical airfoil: Evaluation of initial perforated configuration

The initial evaluation of a large-chord, swept, supercritical airfoil incorporating an active laminar-flow-control (LFC) suction system with a perforated upper surface is documented in a chronological manner, and the deficiencies in the suction capability of the perforated panels as designed are described. The experiment was conducted in the Langley 8-Foot Transonic Pressure Tunnel. Also included is an evaluation of the influence of the proximity of the tunnel liner to the upper surface of the airfoil pressure distribution

The NASA Langley Laminar-Flow-Control Experiment on a Swept Supercritical Airfoil: Basic Results for Slotted Configuration

The effects of Mach number and Reynolds number on the experimental surface pressure distributions and transition patterns for a large chord, swept supercritical airfoil incorporating an active Laminar Flow Control suction system with spanwise slots are presented. The experiment was conducted in the Langley 8 foot Transonic Pressure Tunnel. Also included is a discussion of the influence of model/tunnel liner interactions on the airfoil pressure distribution. Mach number was varied from 0.40 to 0.82 at two chord Reynolds numbers, 10 and 20 x 1,000,000, and Reynolds number was varied from 10 to 20 x 1,000,000 at the design Mach number

Comparison of Visual Analog Pain Score Reported to Physician vs Nurse in Nonoperatively Treated Foot and Ankle Patients

Background: Patient reported outcome measures (PROMs) are taking a more prominent role in Orthopedics as health care seeks to define treatment outcomes. The Visual Analogue Scale (VAS) is considered a reliable measure of acute pain. A previous study found that operative candidates’ VAS pain score was significantly higher when reported to the surgeon compared to the nurse. This study’s aim is to examine whether this phenomenon occurs in nonoperative patients. We hypothesize that patients’ VAS scores reported to the surgeon and a nurse will be the same Methods: This study is a retrospective cohort of 201 consecutive nonoperative patients treated by a single surgeon. Patients were asked to rate pain intensity by a nurse followed by the surgeon using a horizontal VAS, 0 “no pain” to 10 worst pain”. Differences in reported pain levels were compared with data from the previous cohort of 201 consecutive operative patients. Results: The mean VAS score reported to the nurse was 3.2 whereas the mean VAS score reported to the surgeon was 4.2 (p\u3c.001). The mean difference in VAS scores reported for operative patients was 2.9, whereas the mean difference for nonoperative patients was 1.0 (p \u3c .001). Conclusion: This study found statistically significant differences between VAS scores reported to the surgeon versus the nurse in nonoperative patients which support the trend found in our previous study, where operative patients reported significantly higher scores to the surgeon. The mean difference between reported pain scores is significantly higher for operative patients compared to nonoperative patients

Software and information life cycle (SILC) for the Integrated Information Services Organization

This document describes the processes to be used for creating corporate information systems within the scope of the Integrated Information Services (IIS) Center. Issue B describes all phases of the life cycle, with strong emphasis on the interweaving of the Analysis and Design phases. This Issue B supersedes Issue A, which concentrated on the Analysis and Implementation phases within the context of the entire life cycle. Appendix A includes a full set of examples of the deliverables, excerpted from the Network Database. Subsequent issues will further develop these life cycle processes as we move toward enterprise-level management of information assets, including information meta-models and an integrated corporate information model. The phases described here, when combined with a specifications repository, will provide the basis for future reusable components and improve traceability of information system specifications to enterprise business rules

The larva of Nigronia fasciatus Walker (Megaloptera: Corydalidae)

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