Wind tunnel productivity status and improvement activities at NASA Langley Research Center

Putnam, L. E.

doi:10.2514/6.1996-2260

Cited by 3 publications

(2 citation statements)

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“…has been kept since the facility first came on line. 2 Since the formation of the RFB and the initiation of the WTE, all facilities are routinely gathering productivity data. When fully configured, the test planning management system will track the following measures of performance: Figure 7 illustrates how the activity at a wind tunnel is typically proportioned.…”

Section: Ii: Measure Each Stepmentioning

confidence: 99%

“…This process, illustrated in figure 6, accounts for all activities in the testing process from initial request for test time by the customer to delivery of the final data and test close-out. 2 Each step of the process is being examined to reduce time, to reduce resource requirements, and to improve customer satisfaction. For example, all facilities now use an electronic, web-based test request process, a standard test plan format, and standardized pre-test and post-test meeting agendas.…”

Section: 5mentioning

confidence: 99%

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Accelerating ground-test cycle time - The six-minute model change and other visions for the 21st century

Jérôme

1998

36th AIAA Aerospace Sciences Meeting and Exhibit

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The advantage of managing organizations to minimize product development cycle time has been well established. This paper provides an overview of the wind tunnel testing cycle time reduction activities at Langley Research Center (LaRC) and gives the status of several improvements in the wind tunnel productivity and cost reductions that have resulted from these activities. Processes have been examined and optimized. Metric data from monitoring processes provides guidance for investments in advanced technologies. The most promising technologies under implementation today include the use of formally designed experiments, a diverse array of quick disconnect technology and the judicious use of advanced electronic and information technologies.

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Section: Ii: Measure Each Stepmentioning

confidence: 99%

Section: 5mentioning

confidence: 99%

Accelerating ground-test cycle time - The six-minute model change and other visions for the 21st century

Jérôme

1998

36th AIAA Aerospace Sciences Meeting and Exhibit

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Development and status of data quality assurance program at NASA Langley Research Center - Toward national standards

Hemsch

1996

Advanced Measurement and Ground Testing Conference

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Increasing Efficiency at the NTF by Optimizing Model AoA Positioning

Crawford

Spells

2006

44th AIAA Aerospace Sciences Meeting and Exhibit

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The National Transonic Facility (NTF) at NASA Langley Research Center (LaRC) is a national resource for aeronautical research and development. The government, military and private industries rely on the capability of this facility for realistic flight data. Reducing the operation costs and keeping the NTF affordable is essential for aeronautics research. The cost concern here is the liquid nitrogen (LN 2 ) and how much is used in the process of setting the model pitch. Tests were conducted at the NTF in January 2005 to reduce lag in the angle of attack (AoA) data used by the model pitch control system. Lag in both the filter and the digital voltmeter (DVM) contribute to long set times between data points. Reducing these lags was investigated and is discussed here. I IntroductionThe current LN 2 cost is around $90 per ton and NTF can use a ton in about 4 seconds when operating at high Reynolds number conditions. In NTF's effort to reduce cost, a test was undertaken to determine how to reduce the average range of time between data points which is currently 15s -18s. A substantial amount of money can be saved by reducing this time. For example, in a recent test the customer required 5000 data points. If a 4 second per data point reduction could be achieved then that would equate to a savings of roughly $450,000. Putnam1 and Kegelman 2 take a global look at the productivity improvement needs at the NTF in the mid to late 1990s but this test focused on reducing costly nitrogen consumption through reducing lag in the control system. Specifically it concentrated on two aspects of the AoA signal being provided to the control system. The first area is filtering the signal dynamics and the second deals with removing the integrating DVM from the system. Both of these systems create lag that could be reduced but need to be studied to ensure there is not an unacceptable loss in data quality.NTF typically uses an active 4 pole Bessel low-pass filter with the cut-off frequency set to 0.4 Hz. This smoothes the dynamic accelerometer signal to an acceptable level but it induces a lag of about 0.7s (at a 2 deg/s slew rate). As the cut-off frequency is increased the lag will decrease but the dynamics will have more influence on the AoA reading. Doing this has the potential of reducing 0.5s of lag out of the system as long as the data quality remains within acceptable levels.The integrating DVM, by its nature, introduces lag into the system. Integrating at 10 power line cycles coupled with the overhead associated with processing the readings creates about 0.25s to 0.33s of lag. Removing them from the system would have many advantages, it would: eliminate this lag, not require 1 Aerospace Technologist, Aeronautics Systems Engineering Branch, MS 238, Senior Member.

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Wind tunnel productivity status and improvement activities at NASA Langley Research Center

Cited by 3 publications

References 1 publication

Accelerating ground-test cycle time - The six-minute model change and other visions for the 21st century

Accelerating ground-test cycle time - The six-minute model change and other visions for the 21st century

Development and status of data quality assurance program at NASA Langley Research Center - Toward national standards

Increasing Efficiency at the NTF by Optimizing Model AoA Positioning

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