1. Overhauling the 1/50th Scale
NFAC Model
Dorcas Kaweesa
Mechanical Engineering ‘15
University of Portland
NASA Ames Research
Center

2. National Full Scale Aerodynamic Complex (NFAC)
● Used to determine the aerodynamic characteristics and performance of large scale vehicles
o Aircrafts, trucks, parachutes, wind turbines
● Two wind tunnel test sections: 40x80 and 80x120
● Combination of a range of model support systems
o Allow successful completion of aerodynamic and acoustic experiments

3. 1/50th scale NFAC model
● Designed and fabricated to closely simulate the performance of the full scale NFAC facility.
o Performs aerodynamics characteristics’ test of models.
o Used to investigate possible quality of airflow and air exchange.
● Powered by six 10 HP motors in its fan drive system
● Had not been serviced or repaired in several years.

4. 1/50th Scale Project Details
Goal:
● Disassemble motors from fan drive assemblies
● Refurbish motors and and reassemble back in nacelles
● Test and measure RPM, temperature, voltage, current
Motor Specifications:
● Voltage: 480 V
● Frequency: 400 Hz
● Phases: 3
● Horsepower: 10 hp @ 10,000 RPM
● Max RPM: 12,000
● E/F: 1.2 volts/Hz
● Water Cooled

5. Motor Refurbishment Details
● Metal windings steam cleaned and baked to remove moisture
● Water jackets pressure tested
● Dynamic balancing
● Shaft bearings replaced

6. Trial test run
● Baseline for aerodynamic performance testing
● An un-refurbished fan drive assembly was tested for:
o Fan rpm, air speed, temperature, voltage, current, and structural vibrations
o Spun to maximum RPM (10,000 RPM)
● Structural vibrations due to dynamic imbalance

7. Final Phase
● Refurbished motor will be reassembled in nacelle
● Aerodynamic characteristics tested
Future Work:
● Refurbish all motors
● Reassemble a into fan drive assemblies and test aerodynamic characteristics
● All six fan drive assemblies will be assembled in their original configuration in the 1/50th
scale NFAC model circuit and operated to the motors’ maximum rated rpm.

8. Special Thanks to:
The Oregon NASA Space Grant Consortium
Dr. William Warmbrodt and Farid Haddad