Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “coordinate system”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

Automated RTOP Management System

The structure of NASA's Office of Aeronautics and Space Technology electronic information system network from 1983 to 1985 is illustrated. The RTOP automated system takes advantage of existing hardware, software, and expertise, and provides: (1) computerized cover sheet and resources forms; (2) electronic signature and transmission; (3) a data-based information system; (4) graphics; (5) intercenter communications; (6) management information; and (7) text editing. The system is coordinated with Headquarters efforts in codes R,E, and T.

Hayes, P.↗
NASA NTRS1982

Effect of perceived threat on avoidance maneuvers selected while viewing cockpit traffic displays

Ten airline pilots rated the collision danger of air traffic presented on cockpit displays of traffic information (CDTI) while they monitored simulated departures from Denver. They selected avoidance maneuvers when necessary for separation. Most evasive maneuvers were turns rather than vertical maneuvers. Evasive maneuvers chosen for encounters with low or moderate perceived collision danger were generally toward the intruding aircraft. This tendency lessened as the perceived threat level increased. In the highest threat situations pilots turned toward the intruder only at chance levels. Some of the implications of the pilots' turning-towards tendencies are discussed with respect to automatic collision avoidance systems and coordination of avoidance maneuvers of conflicting aircraft.

Smith, J. D.↗
NASA NTRS1984

Perceived threat and avoidance maneuvers in response to cockpit traffic displays

Airline pilots rated their perception of the danger of an air-to-air collision based on cockpit displays of traffic information while they monitored simulated departures. They selected avoidance maneuvers when necessary for separation. Most evasive maneuvers were turns rather than vertical maneuvers. Evasive maneuvers chosen for encounters with lowor moderate-collision danger were generally toward the intruding aircraft. This tendency lessened as the perceived threat level increased. In the highest threat situations, pilots turned toward the intruder only at chance levels. Intruders coming from positions in front of the pilot's ship were more frequently avoided by turns toward than when intruders approached laterally or from behind. Some of the implications of the pilot's turning-toward tendencies are discussed with respect to automatic collision avoidance systems and coordination of avoidance maneuvers of conflicting aircraft.

Smith, J. D.↗
NASA NTRS1984

Goertler instability of compressible boundary layers

The instability of the laminar compressible boundary-layer flows along concave surfaces is investigated. The linearized disturbance equations for the three-dimensional, counter-rotating, longitudinal-type vortices in two-dimensional boundary layers are presented in an orthogonal curvilinear system of coordinates. The basic approximation of the disturbance equations, which includes the effect of the growth of the boundary layer, is considered and solved numerically.

El-Hady, N. M.↗
NASA NTRS1976

Foreign civil aviation competition: 1976 summary and implications

A summary assessment is made of foreign civil aviation as it relates to the posture of the United States civil aviation industry. Major findings include: (1) Main competitors - European Economic Community (EEC) and Union of Soviet Socialist Republics (USSR). (2) Largest commercial market - Transport aircraft. (3) Current market status and projections - U.S. currently dominates the civil aviation market but foreign markets show greater growth trends. (4) Competitive comparisons - Status comparisons are made in technology (aerodynamics, structures and materials, propulsion, avionics, systems, design coordination, and manufacturing); production runs; marketing; and postsales support. The U.S. generally leads except in aerodynamics and propulsion. (5) Multinational ventures - Joint U.S. industry/foreign government development of advanced technology engines is well developed; airframe industry discussions are now underway. (6) Implications - Although the U.S., is currently preeminent in most areas, this may be only a temporary condition. Past U.S. success in aviation has provided many benefits to the nation. These benefits may be lost.

Alford, W. J., Jr.↗
NASA NTRS1987

Case history of FAA/SRI wind shear models

In order to understand the development of the FAA/SRI wind fields, it is important to understand the operating philosophy of the FAA's Wind Shear Program Office. The goal of the office was to ensure an integrated solution to the wind shear problem which addressed three area: ground based equipment and coordination; airborne systems and procedures; and weather prediction. This triply addressed goal was central to the development of the wind fields. The primary user of the wind shear modeling during the FAA's program was airborne simulation. The project requirement was to use wind shear models that resulted from accidents so that effective procedures and/or equipment could be found for hazardous wind shear encounters. The wind shear model development is discussed in detail.

Schlickenmaier, Herbert↗
NASA NTRS1988

Transient heat transfer from shrinking LOX-drop

In order to achieve prescribed experimental conditions in wind tunnels, the nitrogen-oxygen mixture is enriched by injection of liquid oxygen (LOX) upstream of methane burners. The objective of the study is to determine the LOX drop evaporation rate, which is dominated by heat transfer from the air stream (mass transfer mechanism can be later coupled with the solution from the present work). Since the concentration of drops in the surrounding gas is quite high, the concept of infinite medium cannot be utilized. Drop evaporation, as part of system's mass balance, is an important source-term in the finite-difference 2/3-dimensional network terms of laboratory-system (Eulerian) coordinates, while individual drop behavior, including its thermal history, is analyzed in Lagrangian coordinates.

Kondic, Nenad N.↗
NASA NTRS1989

Earth system science: A program for global change

The Earth System Sciences Committee (ESSC) was appointed to consider directions for the NASA Earth-sciences program, with the following charge: review the science of the Earth as a system of interacting components; recommend an implementation strategy for Earth studies; and define the role of NASA in such a program. The challenge to the Earth system science is to develop the capability to predict those changes that will occur in the next decade to century, both naturally and in response to human activity. Sustained, long-term measurements of global variables; fundamental descriptions of the Earth and its history; research foci and process studies; development of Earth system models; an information system for Earth system science; coordination of Federal agencies; and international cooperation are examined.

Source record↗
NASA NTRS1989

Dynamics of articulated structures

An articulated structure is defined as an assembly of flexible bodies that may be coupled by kinematic connections and force elements that permit large relative displacement and rotation. Kinematics of such systems is defined using one reference frame for each body in the system and deformation modal coordinates that define displacement fields within flexible bodies. Deformation kinematics are defined by both elastic vibration and static correction deformation modes. Linear elastic deformation is presumed; i.e., a linear stress-strain relation is valid and relative displacements within each elastic component are small enough so that the theory of linear elasticity applies. Coupling of reference and modal coordinates leads to a system of nonlinear equations of motion. Methods of automatically generating and solving these equations of motion are outlined.

Haug, Edward J.↗
NASA NTRS1990

Control framework for hand-arm coordination

Coordination of multiple manipulators requires cooperation at several levels in the control hierarchy. A distributed processing environment with no hardware dependencies except at the motor servo level would provide a flexible architecture for coordination. A system on these lines is being built to control an articulated hand and an arm. The four levels of control envisaged include a task decomposition level, a planning level, a scheduling level, and a server level. The hand will carry both force and tactile sensors, feedback from these are used to provide adaptive control in grasping tasks. The processing of the sensory information is performed by independent processes, with analyzed information being sent to the relevant layer of the system. The manipulators are also controlled by individual processes. All process can open communications with an active process sending commands or data, or receiving them. The scope of the system and the current setup are described along with future lines of development.

Agrawal, Sanjay↗
NASA NTRS1936

Potential flow about elongated bodies of revolution

This report presents a method of solving the problem of axial and transverse potential flows around arbitrary elongated bodies of revolution. The solutions of Laplace's equation for the velocity potentials of the axial and transverse flows, the system of coordinates being an elliptic one in a meridian plane, are given. The theory is applied to a body of revolution obtained from a symmetrical Joukowsky profile, a shape resembling an airship hull. The pressure distribution and the transverse-force distribution are calculated and serve as examples of the procedure to be followed in the case of an actual airship. A section on the determination of inertia coefficients is also included in which the validity of some earlier work is questioned.

Kaplan, Carl↗
NASA NTRS1994

A 3D-CFD code for accurate prediction of fluid flows and fluid forces in seals

Current and future turbomachinery requires advanced seal configurations to control leakage, inhibit mixing of incompatible fluids and to control the rotodynamic response. In recognition of a deficiency in the existing predictive methodology for seals, a seven year effort was established in 1990 by NASA's Office of Aeronautics Exploration and Technology, under the Earth-to-Orbit Propulsion program, to develop validated Computational Fluid Dynamics (CFD) concepts, codes and analyses for seals. The effort will provide NASA and the U.S. Aerospace Industry with advanced CFD scientific codes and industrial codes for analyzing and designing turbomachinery seals. An advanced 3D CFD cylindrical seal code has been developed, incorporating state-of-the-art computational methodology for flow analysis in straight, tapered and stepped seals. Relevant computational features of the code include: stationary/rotating coordinates, cylindrical and general Body Fitted Coordinates (BFC) systems, high order differencing schemes, colocated variable arrangement, advanced turbulence models, incompressible/compressible flows, and moving grids. This paper presents the current status of code development, code demonstration for predicting rotordynamic coefficients, numerical parametric study of entrance loss coefficients for generic annular seals, and plans for code extensions to labyrinth, damping, and other seal configurations.

Athavale, M. M.↗
NASA NTRS1996

STS 65 Final Report

The report is organized into sections representing the phases of work performed in analyzing the STS 65 results and preparing the instrument for STS 73. Section 1 briefly outlines the Orbital Acceleration Research Experiment (OARE) system features, coordinates, and measurement parameters. Section 2 describes the results from STS 65. The mission description, data calibration, and representative data obtained on STS 65 are presented. Also, the anomalous performance of OARE on STS 65 is discussed. Finally, Section 3 presents a discussion of accuracy achieved and achievable with OARE.

Rice, James E.↗
NASA NTRS1996

STS-73 (USML-2) Final Report

The report is organized into sections representing the phases of work performed in analyzing the STS-73 (USML-2) results. Section 1 briefly outlines the Orbital Acceleration Research Experiment (OARE), system features, coordinates, and measurement parameters. Section 2 describes the results from STS-73. The mission description, data calibration, and representative data obtained on STS-73 are presented. Also, the anomalous performance of OARE on STS-73 is discussed. Finally, Section 3 presents a discussion of accuracy achieved and achievable with OARE.

Rice, James E.↗
NASA NTRS1996

OARE STS-78 (LMS-1) Final Report

The report is organized into sections representing the phases of work performed in analyzing the STS-78 (LMS-1) results. Section 1 briefly outlines the Orbital Acceleration Research Experiment (OARE) system features, coordinates, and measurement parameters. Section 2 describes the results from STS-78. The mission description, data calibration, and representative data obtained on STS-78 are presented. Also, the anomalous performance of OARE on STS-78 is discussed. Finally, Section 3 presents a discussion of accuracy achieved and achievable with OARE. Appendix A discusses the data processing methodology in detail.

Rice, James E.↗
NASA NTRS1996

OARE STS-75 (USMP-3) Final Report

The report is organized into sections representing the phases of work performed in analyzing the STS-75 (USMP-3) results. Section 1 briefly outlines the Orbital Acceleration Research Experiment (OARE) system features, coordinates, and measurement parameters. Section 2 describes the results from STS-75. The mission description, data calibration, and representative data obtained on STS-75 are presented. Also, the anomalous performance of OARE on STS-75 is discussed. Finally, Section 3 presents a discussion of accuracy achieved and achievable with OARE.

Rice, James E.↗
NASA NTRS1998

OARE STS-94 (MSL-1R)

The report is organized into sections representing the phases of work performed in analyzing the STS-94 (MSL-IR) results. STS-94 (MSL1R) is a reflight of the STS-83 (MSL-1) mission which was terminated early because of a fuel cell problem. Section I briefly outlines the OARE system features, coordinates, and measurement parameters. Section 2 describes the results from STS-94. The mission description, data calibration, and representative data obtained on STS-94 are presented. Also, the anomalous performance of OARE on STS-94 is discussed. Finally, Section 3 presents a discussion of accuracy achieved and achievable with OARE. Appendix A discuss the calibration and data processing methodology in detail.

Rice, James E.↗
NASA NTRS1998

OARE STS-87 (USMP-4)

The report is organized into sections representing the phases of work performed in analyzing the STS-87 (USMP-4) results. Section 1 briefly outlines the OARE system features, coordinates, and measurement parameters. Section 2 describes the results from STS-87. The mission description, data calibration, and representative data obtained on STS-87 are presented. Finally, Section 3 presents a discussion of accuracy achieved and achievable with OARE. Appendix A discusses the calibration and data processing methodology in detail.

Rice, James E.↗