Engineering topics

Williams, F. E.

Publications and source records attributed to Williams, F. E..

6 records

NASA NTRS1974

Asymmetrical booster ascent guidance and control system design study. Volume 1: Summary

Dynamics and control, stability, and guidance analyses are summarized for the asymmetrical booster ascent guidance and control system design studies, performed in conjunction with space shuttle planning. The mathematical models developed for use in rigid body and flexible body versions of the NASA JSC space shuttle functional simulator are briefly discussed, along with information on the following: (1) space shuttle stability analysis using equations of motion for both pitch and lateral axes; (2) the computer program used to obtain stability margin; and (3) the guidance equations developed for the space shuttle powered flight phases.

Williams, F. E.↗

NASA NTRS1974

Asymmetrical booster ascent guidance and control system design study. Volume 2: SSFS math models - Ascent

The engineering equations and mathematical models developed for use in the space shuttle functional simulator (SSFS) are presented, and include extensive revisions and additions to earlier documentation. Definitions of coordinate systems used by the SSFS models and coordinate tranformations are given, along with documentation of the flexible body mathematical models. The models were incorporated in the SSFS and are in the checkout stage.

Williams, F. E.↗

NASA NTRS1974

Asymmetrical booster guidance and control system design study. Volume 3: Space shuttle vehicle SRB actuator failure study

The investigation of single actuator failures on the space shuttle solid rocket booster required the analysis of both square pattern and diamond pattern actuator configurations. It was determined that for failures occuring near or prior to the region of maximum dynamic pressure, control gain adjustments can be used to achieve virtually nominal mid-boost vehicle behavior. A distinct worst case failure condition was established near staging that could significantly delay staging. It is recommended that the square pattern be retained as a viable alternative to the baseline diamond pattern because the staging transient is better controlled resulting in earlier staging.

Williams, F. E.↗

NASA NTRS1972

Spacecraft boost and abort guidance and control systems requirement study, boost dynamics and control analysis study. Exhibit A: Boost dynamics and control anlaysis

The simulation developments for use in dynamics and control analysis during boost from liftoff to orbit insertion are reported. Also included are wind response studies of the NR-GD 161B/B9T delta wing booster/delta wing orbiter configuration, the MSC 036B/280 inch solid rocket motor configuration, the MSC 040A/L0X-propane liquid injection TVC configuration, the MSC 040C/dual solid rocket motor configuration, and the MSC 049/solid rocket motor configuration. All of the latest math models (rigid and flexible body) developed for the MSC/GD Space Shuttle Functional Simulator, are included.

Williams, F. E.↗

NASA NTRS1972

The Valuation of Scientific and Technical Experiments

Rational selection of scientific and technical experiments for space missions is studied. Particular emphasis is placed on the assessment of value or worth of an experiment. A specification procedure is outlined and discussed for the case of one decision maker. Experiments are viewed as multi-attributed entities, and a relevant set of attributes is proposed. Alternative methods of describing levels of the attributes are proposed and discussed. The reasonableness of certain simplifying assumptions such as preferential and utility independence is explored, and it is tentatively concluded that preferential independence applies and utility independence appears to be appropriate.

Williams, F. E.↗

NASA NTRS1972

Aerothermodynamic measurements for space shuttle configuration in hypersonic wind tunnels

The effect of shuttle configuration geometry, angle of attack, and free stream flow conditions on the heat-transfer distribution as influenced by three-dimensional effects, the wing-fuselage shock-interaction, and resultant wing-impingement phenomena are examined. In addition, the data provided information regarding the flow field in the vicinity of the nose and boundary layer transition in the plane of symmetry of the fuselage. The data included measurements of the surface pressure, the heat transfer rate distributions, (using models instrumented with thermocouples and models painted with thermographic phosphor) and schlieren and shadowgraph photographs. Posttest photographs of the painted models supplemented the heat transfer data.

Bertin, J. J.↗