Engineering topics

Wagner, William R.

Publications and source records attributed to Wagner, William R..

8 records

NASA NTRS1990

Testing Bearing Balls For Ignition In Liquid Oxygen

Inexpensive, safe apparatus built to test cooling by, ignition in, and nucleate boiling to film boiling of liquid oxygen flowing around ball bearings. Provides for heating of bearing specimens, direct observations, and measurements of temperatures and temperature distributions by thermocouples and infrared sensors. Used to evaluate suitability of various materials and surface treatments for ball bearings in high-pressure liquid-oxygen turbopumps. Ball rests in fixture while liquid oxygen flows around it. Flow reversed so observer or infrared sensor can view phenomena on trailing or leading side of ball.

Wagner, William R.↗

NASA NTRS1990

Thermal-Transient Testing Of Turbine Blades

Testing apparatus applies pulses of heat to turbine blade to determine resistance to thermal fatigue. Uses nonintrusive inductive heating and records distribution of temperature on blade with infrared video camera. Allows precise control of heating and cooling. Designed for testing blades used in advanced high-pressure, high-temperature turbines.

Wagner, William R.↗

NASA NTRS1988

Self-Protecting Heat Exchanger

Double-wall heat-exchanger tube protects from overloads by changing thermal resistance automatically. When temperature at any location on tube increases above prescribed limit, thermal resistance through walls of tube increases at location. Prevents local excess heat load from overheating tube or boosting internal pressure and weakening tube, shortening life expectancy, or destroying it. When heat load falls to normal level, tube automatically lowers thermal resistance and resumes heat exhange at rated capacity.

Wagner, William R.↗

NASA NTRS1988

Predicting Temperatures In Ball Bearings

Computer simulations speed design studies. Analyses performed in two or three dimensions. Sizes and shapes of components approximated by zones or nodes connected by gridlines. From geometric information about grids and boundary conditions, properties of bearing and lubricant materials, and information supplied by users, thermal-analysis programs generate mathematical models for thermal transport. Thermal analysis of high-speed rolling contact bearings matured so much that computerized numerical simulations replace expensive time consuming full scale experiments.

Wagner, William R.↗

NASA NTRS1988

Designing Film-Cooled Turbine Disks

Technique optimizes weight and speeds of disks in film-cooled turbines. Proposed iterative approach to design enables shaping of turbine disks partly according to temperature profiles. Suitable for design of advanced stationary, aircraft, and rocket turbines.

Wagner, William R.↗

NASA NTRS1988

Test Apparatus For Oversize Ball-Bearing Models

See-through machine enables direct observation and indirect measurements at moderate speeds. Model of ball bearing, six times larger than real bearing, rotated in test machine. Transparency of walls and simulated lubricant reveal flow patterns and allow visible-light and infrared photographs to be made.

Wagner, William R.↗

NASA NTRS1988

Designing A Transonic Nozzle For Efficient Cooling

Design for high-pressure transonic-flow nozzle increases effectiveness of coolant flowing in passages in wall nozzle. Revised curvatures of nozzle wall provide shortened transonic region and enable selection of approach- and discharge-wall angles for maximum cooling. Design enables wall to operate at lower temperature, reducing thermal fatigue and increasing life expectancy of wall. Also enables coolant to flow through wall channels with lower pressure drop and lower pumping pressure.

Wagner, William R.↗

NASA NTRS1987

Labyrinthine turbine-rotor-blade tip seal

Means for sealing the tip 18 of a rotor turbine blade 10 against tip leakage flow comprising a multiplicity of recesses 30 formed in the surface of the tip 18. The recesses 30 are preferably formed in a labyrinthine or slaggered pattern which interposes at least one recess 30 in every leakage flow path across the tip 18 from the pressure side 26 to the suction side 28 of the blade 10.

Wagner, William R.↗